CHAPTER V

DEBATING

60. The Nature of Debate. The essential difference between debate

and written argument lies not so much in the natural difference between

all spoken and written discourse as in the fact that in a debate of any

kind there is the chance for an immediate answer to an opponent.

Quickness of wit to see the weak points on the other side, readiness in

attacking them, and resource in defending one's own points make the

debater, as distinguished from the man who, if he be given plenty of

time, can make a formidable and weighty argument in writing. The best

debating is heard in deliberative bodies which are not too large, and

where the rules are not too elaborate. Perhaps the best in the world is

in the British House of Commons, for there the room is not so large that

hearing is difficult, and skill in thrust and parry has been valued and

practiced for generations.

The military figure for argument is more apposite in debate than

anywhere else, for in the taking of the vote there is an actual victory

and defeat, very different in nature from the barren decision of judges

in intercollegiate and interscholastic contests. It is undoubtedly rare

that a particular debate in any legislative body actually changes the

result; but in the long run the debates in such bodies do mold public

opinion, and within the body amalgamate or break up party ties. The

resource and the ready knowledge of the subject under debate necessary

to hold one's own in such running contests of wit Is an almost essential

characteristic of a party leader. It is on these two qualities that I

shall chiefly dwell in this chapter.

61. Subjects for Debate. Debate almost always deals with questions

of policy. In trials before a jury there is something approaching a

debate over questions of fact; but the rules of evidence are so special,

and within their range so strict, that even though the arguments are

spoken, they can have little of the free give and take which makes the

life and the interest of a real debate. Accordingly I shall draw my

illustrations here from questions of policy, and so far as is possible

from the sort of question that students are likely to turn their

attention to. The later years of school and the whole of the college

course are often the molding years for a man's views on all sorts of

public questions. It has been said that a man's views rarely change

after he is twenty-five years old; and though one must not take such a

dictum too literally, yet unquestionably it has truth. At any rate it is

certain that a student, whether in high school or college, if he is to

do his duty as a citizen, must begin to think out many of the questions

which are being decided in Congress, in state legislatures, and in

smaller, more local bodies. At the same time, in every school and

college questions are constantly under discussion of a nature to provide

good practice in debate. Some of these questions must be decided by

school committee, principal, faculty, or trustees, and most of them call

for some looking up of facts. They would provide admirable material for

the development of judgment and resource in debating, and in some cases

a debate on them might have effect on the actual decision.

The choice of subject is even more important for debating than for

written argument. In a written argument if you have a question which has

two defensible sides, it does not make much difference whether one is

easier to defend than the other: in a debate such a difference might

destroy the usefulness of the subject. Though to some older minds the

abolition of football is a debatable question, before an audience of

undergraduates who had to vote on the merits of the question the subject

would be useless, since the side which had to urge the abolition would

here have an almost impossible task. So in a debate on the "closed

shop," in most workingmen's clubs the negative would be able to

accomplish little, for the other side would be intrenched in the

prejudices and prepossessions of the audience. In political bodies

unevenness of sides is of common occurrence, for a minority must always

defend its doctrines, no matter how overwhelming the vote is certain to

be. In the formal debates of school and college, on the other hand,

where the conditions must be more or less artificial, the first

condition is to choose a question which will give the two sides an even

chance.

A fair test of this evenness of sides is to see whether the public which

is concerned with the question is evenly divided: if about the same

number of men who are acquainted with the subject and are recognized as

fair-minded take opposite sides, the question is probably a good subject

for debate. Even this test, however, may be deceptive, since believing a

policy to be sound and being able to show that it is so are very

different matters. The reasons for introducing the honor system into a

certain school or college are probably easier to state and to support

than the reasons against introducing it; yet the latter may be

unquestionably weighty.

In general, arguments which rest on large and more or less abstract

principles are at a disadvantage as against arguments based on some

immediate and pressing evil or on some obvious expediency. Arguments for

or against a protective tariff on general principles of political

economy are harder to make interesting and, therefore, cogent to the

average audience than are those based on direct practical gains or

losses. This difference in the ease with which the two sides of a

question can be argued must be taken into account in the choice of a

subject.

In the second place, the subject should be so phrased that it will

inevitably produce a "head-on" collision between the two sides. If such

a proposition as "The present city government should be changed" were

chosen for a debate, one side might argue it as a question of the party

or of the men who happened to be in control at the time, and the other

as a question of the form of government. So on the question of

self-government for a college or school, unless the type of

self-government were carefully defined, the two sides might argue

through the debate and not come in sight of each other. What was said in

Chapter II about framing the proposition for an argument applies with

even more force to finding the proposition for a debate; for here if

they do not meet on an irreconcilable difference, there is little use in

their coming together.

In the third place, it is desirable that the proposition should be so

framed as to throw the burden of proof on the affirmative. Unless the

side which opens the debate has something definite to propose, the

debate must open more or less lamely, for it is hard to attack or oppose

something which is going to be set forth after you have finished

talking. Here, however, as in the case of written arguments, it must be

remembered that burden of proof is a vague and slippery term; "he who

asserts must prove" is a maxim that in debate applies to the larger

issues only, and the average audience will give themselves little

trouble about the finer applications of it. If you are proposing a

change in present conditions, and the present conditions are not very

bad, they will expect you to show why there should be a change, and to

make clear that the change you propose will work an improvement. It is

only when conditions have become intolerable that an audience thinks

first of the remedy. In the ordinary school or college, for example,

there is little reason in current conditions for introducing the honor

system in examinations: in such a case the burden of proof on the

affirmative would be obvious, If, however, as occasionally happens,

there has been an epidemic of dishonesty in written work, then the

authorities of the school and the parents would want to know why there

should not be a change. But it would both bore and confuse an audience

to explain to them at length the theory of the shifting of the burden of

proof; and the chances are that they would say, "Why doesn't he prove

his point, and not spend his time beating about the bush?"

Finally, the proposition should, if possible, give to the negative as

well as to the affirmative some constructive argument. If one side

occupies itself wholly with showing the weakness of the arguments on the

other side, you get nowhere on the merits of the question; for all that

has been shown in the debate, the proposition put forward by the

affirmative may be sound, and the only weakness lie in its defenders.

Moreover, where the negative side finds no constructive argument on the

merits of the question, or elects to confine itself to destructive,

arguments, it must beware of the fallacy "of objections"; that is, of

assuming that when it has brought forward some objections to the

proposition it has settled the matter. As I have so often pointed out in

this treatise, no question is worth arguing unless it has two sides; and

that is merely saying, in another way, that to both sides there are

reasonable objections. Where a negative side confines itself to

destructive arguments it must make clear that the objections it presents

are really destructive, or at any rate are clearly more grave than those

which can be brought against leaving things as they are. And if they

confine themselves to destroying the arguments brought forward by the

affirmative in this particular debate, they must make clear that these

arguments are the strongest that can be brought forward on that side.

On all questions as to construction of terms and burden of proof, it

should be understood beforehand that the judges of a formal debate will

heavily penalize anything like pettifogging or quibbling. The two sides

should do their best to come to a "head-on" issue; and any attempt at

standing on precise definition, or sharp practice in leading the other

side away from the main question, should be held to be not playing the

game. Where the judges are drawn from men of experience in affairs, as

is usually the case, they will estimate such boyish smartnesses at their

true value.

62. Technical Forms. The formal debates of school and college have

certain forms and conventions which are partly based on parliamentary

procedure, partly have been worked out to make these debates more

interesting and better as practice; and there are certain preliminary

arrangements that improve debating both as intellectual training and as

fun. I shall speak first of the forms and conventions.

In debates in school and college it is usual to have two or three on a

side, and for good reasons. In the first place, the labor of working up

the subject is shared, and it is better fun working with some one else.

Then, in the debate itself there is more variety. In class debates there

are usually two speakers on each side, with provision of time for

several four- or five-minute speeches from the floor before the closing

speeches in rebuttal.[64] If there are as many speakers as this a

two-hour period must be allowed. This allotment of time will naturally

be adapted to special conditions; as, for example, where it is desirable

that there shall be more speakers from the floor, or where it is desired

to give the whole time to the regular debaters. In important

intercollegiate debates there are usually three speakers, each of whom

has ten minutes for his main speech and five minutes for rebuttal. This

arrangement varies greatly, however, in different places, and not

infrequently there is only one speech in rebuttal. The affirmative is

usually given the last speech, on the theory that it is a disadvantage

to have to open the debate. Obviously, however, in practice the reverse

may often be true, since a skillful speech in opening may largely

determine the course of the debate; and for this reason many debating

societies and colleges allow the closing speech to the negative. It is

wise not to look on any of these rules as inviolable.[65]

The distribution of the points between the speakers on a side should be

made beforehand, but always with the understanding that the exigencies

of the debate may upset the arrangement. We shall see presently the

advantage there is in having each member of a "team" prepared to defend

all the points on his side. The only speech for which a fixed program

can be made beforehand is the first speech on the affirmative: obviously

this must at any rate expound the main facts which the audience must

know in order to understand the speeches that follow. After that each

speaker should be prepared either to answer directly what has just been

said or to explain why he postpones the answer. At the same time, unless

his hand has been forced, he must make the point or points which have

been committed to him in the preliminary plan of campaign. Each speaker

after the first generally takes a minute or two to sum up the position

as his side sees it; and the final speaker on each side ought to save

time to recapitulate and drive home the main points that his side has

made and the chief objections to the arguments on the other side. Beyond

these suggestions, which should not be allowed to harden into invariable

rules, much must be left to the swift judgment of the debaters. It is a

good test of skill in debating to know just when to stick to such rules,

and when to break away from them.

A debater uses certain forms which have long been established in

parliamentary law. To begin with, he never uses the name of his

opponent: if he has to refer to him he refers indirectly in some such

form as "the last speaker," "the first speaker for the affirmative,"

"the gentlemen from Wisconsin," "our opponents," "my colleague who has

just spoken." This is an inviolable rule of all debating bodies, whether

a class in school or college or one of the Houses of Congress.

In a formal debate the subject is stated by the presiding officer, who

is usually not one of the judges, and he also introduces each of the

speakers in the order agreed on beforehand.

In class debates the subject is usually given out by the instructor, who

may assign the speakers, or may call for volunteers, or may let each

member of the class take his turn in regular rotation. This distribution

will usually work itself out to suit the class and the circumstances. In

interscholastic and intercollegiate debates the subject is generally

chosen by letting one side offer a number of subjects from which the

other selects one. Sometimes the team which does not have the choice of

subject has the choice of sides after the other team has picked the

subject. In a triangular debate two or three subjects are proposed by

each team, and then one is selected by preferential voting of all the

contestants, first choice counting three points, second two, and third

one. In such a contest each institution has two teams, one of which

supports the affirmative, and the other the negative; and the three

debates take place on the same day or evening.

In class debates the two sides should unite in preparing an agreed

statement of facts, which shall contain so much of the history of the

case as is pertinent, facts and issues which it is agreed shall be

waived, and a statement of the main issues. Furthermore, it is highly

desirable that the sides should submit to each other outline briefs

covering the main points of their case. With such preparations there is

little probability that there can be any failure to meet. The same

preparations would be useful in interscholastic and intercollegiate

debates, wherever they are practicable. Anything which leads to a

thorough discussion of identical points and to the consequent

illumination of the question makes these entertainments more valuable.

For intercollegiate and interscholastic debates it is wise to have some

sort of instructions for the judges, which should be agreed on

beforehand. These instructions must make clear that the decision is to

turn not on the merits of the question, as in real life, but on the

merits of the debaters. Among those merits the substance should count

much more than the form. Of the points that count in judging the

substance of the debate the instructions may note keenness of analysis,

power of exposition, thoroughness of preparation, judgment in the

selection of evidence, readiness and effectiveness in rebuttal, and

grasp of the subject as a whole. For form the instructions may mention

bearing, ease and appropriateness of gesture, quality and expressiveness

of voice, enunciation and pronunciation, and general effectiveness of

delivery. Sometimes these points are drawn up with percentages to

suggest their proportionate weight; but it is doubtful whether so exact

a calculation can ever be of practical value. In most cases the judges

will decide from a much less articulate sense of which side has the

advantage.[66]

63. Preparations for Debating. Since the chief value of debating,

as distinguished from written arguments, is in cultivating readiness and

flexibility of wit, the speaking should be as far as possible

extemporaneous. This does not imply that the speaking should be without

preparation: on the contrary, the preparation for good debating is more

arduous than for a written argument, for when you are on your feet on

the platform you cannot run to your books or to your notes to refresh

your memory or to find new material. The ideal debater is the man who so

carries the whole subject in his mind that the facts flow to his mind as

he talks, and fit into the plan of his argument without a break. To the

rare men who remember everything they read, such readiness is natural,

but to far the largest number of speakers it comes only through hard

study of the material. Daniel Webster declared that the material for his

famous Reply to Hayne had been in his desk for months. In so far as

debating consists in the recitation of set speeches written out and

committed to memory beforehand, it throws away most of what makes

debating valuable, and tends to become elocution. We shall consider

here, therefore, ways in which speakers can make themselves so familiar

with the subject to be debated that they can confidently cut loose from

their notes.

In the first place, each debater on a team should prepare himself on the

whole subject, not only on the whole of his own side, but also on the

whole of the other side. It is usual to divide up the chief points that

a team is to make among its different members; but in the sudden turns

to which every debate is liable such assignment may easily become

impossible. If the other side presents new material or makes a point in

such a way as manifestly to impress the audience, the next speaker may

have to throw over the point assigned to him and give himself

immediately to refuting the arguments just made. Then his points must be

left to his colleagues, and they must be able to use them to effect.

Likewise a team should know the strong points on the other side as well

as on its own, and come to the platform primed with arguments to meet

them. In intercollegiate contests, to insure this fore-knowledge of the

other side the speakers as part of their preparation meet men from their

own college who argue out the other side in detail and at length. In a

triangular contest each team from a college has the advantage of having

worked up the subject in actual debate against the other. The more

thoroughly you have worked up both sides of the question, the less

likely are you to be taken by surprise by some argument which you do not

know how to meet.

64. On the Platform. When it comes to the actual debate experience

shows that speeches committed to memory are almost always ineffective as

compared with extemporaneous speaking. Even when your confidence is not

disturbed by a slippery memory there is an impalpable touch of the

artificial about the prepared speech which impairs its vitality. On the

other hand, especially with the first speeches on each side, you cannot

get to your feet and trust entirely to the inspiration of the moment;

you must have something thought out. One of the most notable lecturers

in Harvard University prepares his lectures in a way which is an

excellent model for debaters. He writes out beforehand a complete

analytical and tabulated plan of his lecture, similar to the briefs

which have been recommended here in Chapter II, with each of the main

principles of his lecture, and with the subdivisions and illustrations

inserted. Then he leaves this outline at home and talks from a full and

well-ordered mind. Some such plan is the best possible one for the main

speeches in a debate. Often the plan can be most easily prepared by

writing out the argument in full; and this expansion of the argument has

the added advantage of providing you with much of your phrasing. But it

is better not to commit the complete argument to memory: the brief of

it, if thoroughly digested and so studied as to come readily to mind, is

enough. Then practice, practice, practice, will give the ease and

fluency that you need.

The rebuttal should always be extemporaneous. Even if you have foreseen

the strongest points made by your opponent and prepared yourself to meet

them, you cannot foresee just the way he will make the points. Nothing

is more awkward in a debate than to begin with a few obviously

extemporaneous remarks, and then to let loose a little speech which has

been kept, as it were, in cold storage, and which just misses fitting

the speech to which it should be an answer. It is better to make the

rebuttal a little less sweeping than it might be and have it fall pat on

the speech which it is attacking. Ready and spontaneous skill in

rebuttal is the final excellence of debating. At the same time the skill

should be so natural that wit and good humor may have their chance. If

from the beginning you practice making your speeches in rebuttal

offhand, you will constantly gain in confidence when you are called on

to speak.

Whether to take notes on to the platform or not is a somewhat disputed

question. If you can speak without them and hold without stumbling to

the main course of your argument, so much the better. On the other hand,

most lawyers have their briefs when they are arguing on points of law,

and some sort of rough notes when they are arguing before a jury; and

when unassumingly and naturally used, notes are hardly observed by an

audience. Only, if you do have notes, do not try to conceal them: hold

them so that the audience will know what they are, and will not wonder

what you are doing when you peer into the palm of your hand.

If you have passages to quote from a book or other document, have the

book on the table beside you; its appearance will add substance to your

point, and the audience will have ocular proof that you are quoting

exactly.

For purposes of rebuttal it is usual to have material on cards arranged

under the principal subdivisions of the subject, so that they can

readily be found. These cards can be kept in the small wooden or

pasteboard boxes that are sold for the purpose at college stationers. If

the cards have the proper kind of headings, you can easily look them

over while your opponent is speaking and pull out the few that bear on

the point you are to meet. Examples of these cards have been given in

Chapter II. The important thing for their use in a debate is to have the

headings so clear and pertinent that you can instantly find the

particular card you want. Naturally you will have made yourself

thoroughly familiar with them beforehand.

When you have to use statistics, simplify them so that your hearers can

take them in without effort. Large numbers should be given in round

figures, except where some special emphasis or perhaps some semihumorous

effect is to be gained by giving them in full. Quotations from books or

speeches must of necessity be short: where you have only ten minutes

yourself you cannot give five minutes to the words of another man.

Keep your audience in good humor; if you can occasion ally relieve the

solemnity of the occasion by making them laugh, they will like you the

better for it, and think none the worse of your argument. On the other

hand, remember that such diversion is incidental, and that your main

business is to deal seriously with a serious question. The uneasy

self-consciousness that keeps a man always trying to be funny is

nowhere more out of place than in a debate.

65. Voice and Position. The matter of delivery is highly important,

and here no man can trust to the light of nature. Any voice can be made

to carry further and to be more expressive, and the poorest and thinnest

voice can be improved. Every student who has a dream of being a public

speaker should take lessons in elocution or in singing or in both. The

expressiveness as well as the carrying power and the endurance of a

voice depend on a knowledge of how to use the muscles of the chest,

throat, and face; and trainers of the voice have worked out methods for

the proper use of all these sets of muscles. A man who throws his breath

from the top of his chest and does not use the great bellows that reach

down to his diaphragm can get little carrying power. So with the throat:

if it is stiff and pinched the tones will be high and forced, and

listening to them will tire the audience nearly as much as making them

will tire the speaker. Finally, the expressiveness of a voice, the

thrill that unconsciously but powerfully stirs hearers, is largely a

matter of the resonance that comes from the spaces above the mouth and

behind the nose. A humorous singing teacher once declared that the soul

resides in the bridge of the nose; and the saying is not so paradoxical

as it sounds. Lessons in the use of all these parts, and faithful

practice in the exercises which go with them, are essential for any man

who wishes to make a mark in public speaking.

With the use of the voice, though less essential, goes the position and

bearing on the platform. It is not necessary to insist that the more

natural this is, the better. If you can wholly forget yourself and think

only of your points, the chances are that your attitudes and position

will take care of themselves. Only, before thus forgetting yourself,

form the habit of talking without putting your hands in your pockets.

You ought to need your hands to talk with, if not as much as a Frenchman

or an Italian, yet enough to emphasize your points naturally. The mere

physical stimulus to the eye of an audience in following your movements

will help to keep their attention awake. Every one who has tried

lecturing to a large class knows how much easier it is to hold them if

he stands up and moves a little from time to time. Learn to stand easily

and naturally, with your chest well expanded, and your weight

comfortably balanced on your feet. If it comes natural to you, move

about the stage slightly from time to time; but be careful not to look

each time you move as if a string had been pulled. In attitude and

gesture the only profitable council is, Be natural.

For all these matters of preparation, both of what you are going to say,

the use of your voice, and your attitude and action on the platform, be

prepared for hard practice with competent criticism. It is a good plan

to practice talking from your outlines with your watch open, until you

can bring your speech to an end in exactly the time allowed you. The

gain in confidence when you go to the debate will in itself be worth the

time. Again, practice speaking before a glass to make sure that you have

no tricks of scowling or of making faces when you talk, and to get used

to standing up straight and holding yourself well. What you see for

yourself of your own ways will help you more than the advice of a

critic.

But in all your preparation think beyond the special debate you are

preparing for. What you are or should be aiming at is habit--the

instinctive, spontaneous execution of rules which you have forgotten.

When the habit is established you can let all these questions of voice,

of attitude, of gesture, drop from your mind, and give your whole

attention to the ideas you are developing, and the language in which you

shall clothe them. Then the tones of your voice will respond to the

earnestness of your feeling, and your gestures will be the spontaneous

response to the emphasis of your thought. You will not be a perfect

debater until all these matters are regulated from the unconscious

depths of your mind.

In your attitude towards the debaters on the other side be scrupulously

fair and friendly. In class debates the matter is finished when the

debate is over; and what you are after is skill, and not beating some

one. In interscholastic and intercollegiate debates victory is the end;

but even there, after the debate you will often go out to supper with

your opponents. Therefore demolish their arguments, but do not smash

their makers.

If the first speech falls to you, set forth the facts in such a way that

not only your opponents will have no corrections or protests to make,

but that they will be wholly willing to make a start from your

foundation. Yield all trivial points: it is a waste of your time and

proof of an undeveloped sense of proportion to haggle over points that

in the end nobody cares about. You have won a point if you can make the

audience and the judges feel that you are anxious to allow everything

possible to the other side.

If your opponent trips on some small point of fact or reasoning, don't

heckle him; let it pass, or, at the most, point it out with some kindly

touch of humor. If his facts or his reasoning are wrong on important

points, that is your opportunity, and you must make the most of it.

Even then, however, stick to the argument, and keep away from any

appearance of being personal.

66. The Morals of Debating. There is a moral or ethical side to

practice in debating which one cannot ignore. It is dangerous to get

into the habit of arguing lightly for things in which one does not

believe; and students may be forced into doing this if great care is not

taken in the choice of subjects and sides. The remedy lies in using, so

far as they can be kept interesting, questions in which there is no

moral element; but still better in assigning sides to correspond with

the actual views and preferences of the debaters. Where a question of

principle is involved no one should ever argue against his beliefs. The

better class of lawyers are scrupulous about this: they will not accept

a brief which they believe to be in a cause which ought not to win. If

you have clearly made up your mind on a question of public policy, you

are in a false position if you argue, even for practice, against what

you believe to be the right.

The formal debates of school and college are of necessity barren of

practical result; yet even here your discussions have a potent effect in

molding your opinions. It is a habit of mankind to start idly talking on

a subject, and as idly taking sides; then, when the talk grows warmer,

in the natural desire to carry a point to talk themselves into belief.

This is a human, though not a very reasonable way of framing your views

on public questions; and it does not make either for consistency or for

usefulness as a voter. It is not good to back one's self into opinions

of what makes for the common weal.

Furthermore, debate is something very different from dispute: to talk

round and round a subject, contradicting blindly and asserting without

bringing forward facts, has its place in our life with our friends, so

long as it is good-natured; but it does not bring illumination. The

essence of debate, whether in a classroom, in a city council, or in

Congress, should be to throw light into dark corners, and to disentangle

the view that most makes for the general good. For us in America

_noblesse oblige_ applies to every educated man. The graduate of a high

school, and, even more, the graduate of a college, has taken exceptional

benefits from the community. This obligation he can in part repay by

helping all citizens to a better understanding of the issues on which

the progress of the nation turns.

Finally, debating should share the zest that comes of any good game that

means hard work and an honorable struggle with opponents one respects

and likes. It is preeminently a social occupation. The House of Commons

has long been noted as the best club in England; and this sense of

fellowship, of continuing friendship and intimacy, gives a charm to

English parliamentary life which is hardly possible with the unwieldy

numbers and huge hall of our own House of Representatives, but does

spring out of the smaller and continuing membership of the Senate. A

class in debating should have the sense of comradeship which comes of

hard work together and the trying out of one's own powers against one's

equals and betters, and from the memory of hard-fought contests; and

intercollegiate and interscholastic contests should be carried on in the

same spirit of zest in the hard work, of a sane desire to win, and of

comradeship with worthy opponents.

EXERCISES

1. Name three questions in national affairs which have been debated

within a month, on which you could profitably debate; three in state

affairs; three in local affairs.

2. Name two subjects affecting your school or college which are under

debate at the present time.

3. Name two subjects on which you could write an argument, but which

would not be profitable for debate. Explain the reason.

4. Name two good subjects for a debate drawn from athletics; two from

some current academic question; two from local or municipal affairs.

5. Find a proposition in which the two sides to a debate might in good

faith pass each other without meeting. Make it over so that the issue

would be unavoidable.

6. Frame a proposition in which the burden of proof would not be on the

affirmative. Make it over so that the burden of proof would fall on the

affirmative.

7. Draw up a scheme for a debate on one of the propositions in Exercise

4, with a tentative assignment of points to three debaters on a side.

8. Draw up a set of instructions to judges for an intercollegiate or

interscholastic debate, so framed as to produce a decision on the points

which seem to you the most important.

9. Prepare yourself for a five-minute extemporaneous speech on a subject

on which you have written an argument.

10. Name three questions on which you could not, without violence to

your convictions, argue on more than one side.

APPENDIX I

EXAMPLES OF ARGUMENT

THE THREE HYPOTHESES RESPECTING THE HISTORY OF NATURE[67]

THOMAS H. HUXLEY

This is the first of three lectures which make a continuous argument,

which were delivered in New York. September 18, 20, and 22, 1876. It

should therefore be regarded as the introductory part of the argument;

and as a matter of fact it does not get to Huxley's positive proof, but

is occupied with disposing of the other theories. This refutation

finished, Huxley was then at liberty to go ahead with the affirmative

argument, as he indicates in the last paragraph of the lecture.

The argument is a notable piece of reasoning on a scientific subject, in

terms which make it intelligible to all educated men. When Huxley spoke,

the heat which had been kindled by the first announcement of the theory

of evolution in Darwin's "Origin of Species" was still blazing; and

there were many church people who held that the theory was subversive of

religion, without giving themselves the trouble to understand it. This

timid frame of mind explains Hurley's mode of approach to the subject.

We live in and form part of a system of things of immense diversity and

perplexity, which we call Nature; and it is a matter of the deepest

interest to all of us that we should form just conceptions of the

constitution of that system and of its past history. With relation to

this universe, man is, in extent, little more than a mathematical point:

in duration but a fleeting shadow: he is a mere reed shaken in the winds

of force. But, as Pascal long ago remarked, although a mere reed, he is

a thinking reed; and in virtue of that wonderful capacity of thought, he

has the power of framing for himself a symbolic conception of the

universe, which, although doubtless highly imperfect and inadequate as a

picture of the great whole, is yet sufficient to serve him as a chart

for the guidance of his practical affairs. It has taken long ages of

toilsome and often fruitless labor to enable man to look steadily at the

shifting scenes of the phantasmagoria of Nature, to notice what is fixed

among her fluctuations, and what is regular among her apparent

irregularities; and it is only comparatively lately, within the last few

centuries, that the conception of a universal order and of a definite

course of things, which we term the course of Nature, has emerged.

But, once originated, the conception of the constancy of the order of

Nature has become the dominant idea of modern thought. To any person who

is familiar with the facts upon which that conception is based, and is

competent to estimate their significance, it has ceased to be

conceivable that chance should have any place in the universe, or that

events should depend upon any but the natural sequence of cause and

effect. We have come to look upon the present as the child of the past

and as the parent of the future; and, as we have excluded chance from a

place in the universe, so we ignore, even as a possibility, the notion

of any interference with the order of Nature. Whatever may be men's

speculative doctrines, it is quite certain that every intelligent person

guides his life and risks his fortune upon the belief that the order of

Nature is constant, and that the chain of natural causation is never

broken.

In fact, no belief which we entertain has so complete a logical basis as

that to which I have just referred. It tacitly underlies every process

of reasoning; it is the foundation of every act of the will. It is based

upon the broadest induction, and it is verified by the most constant,

regular, and universal of deductive processes. But we must recollect

that any human belief, however broad its basis, however defensible it

may seem, is, after all, only a probable belief, and that our widest and

safest generalizations are simply statements of the highest, degree of

probability. Though we are quite clear about the constancy of the order

of Nature, at the present time, and in the present state of things, it

by no means necessarily follows that we are justified in expanding this

generalization into the infinite past, and in denying, absolutely, that

there may have been a time when Nature did not follow a fixed order,

when the relations of cause and effect were not definite, and when

extranatural agencies interfered with the general course of Nature.

Cautious men will allow that a universe so different from that which we

know may have existed; just as a very candid thinker may admit that a

world in which two and two do not make four, and in which two straight

lines do inclose a space, may exist. But the same caution which forces

the admission of such possibilities demands a great deal of evidence

before it recognizes them to be anything more substantial. And when it

is asserted that, so many thousand years ago, events occurred in a

manner utterly foreign to and inconsistent with the existing laws of

Nature, men, who without being particularly cautious, are simply honest

thinkers, unwilling to deceive themselves or delude others, ask for

trustworthy evidence of the fact. Did things so happen or did they not?

This is a historical question, and one the answer to which must be

sought in the same way as the solution of any other historical problem.

* * * * *

So far as I know, there are only three hypotheses which ever have been

entertained, or which well can be entertained, respecting the past

history of Nature. I will, in the first place, state the hypotheses, and

then I will consider what evidence bearing upon them is in our

possession, and by what light of criticism that evidence is to be

interpreted.

Upon the first hypothesis, the assumption is, that phenomena of Nature

similar to those exhibited by the present world have always existed; in

other words, that the universe has existed from all eternity in what may

be broadly termed its present condition.

The second hypothesis is, that the present state of things has had only

a limited duration; and that, at some period in the past, a condition of

the world, essentially similar to that winch we now know, came into

existence, without any precedent condition from which it could have

naturally proceeded. The assumption that successive stales of Nature

have arisen, each without any relation of natural causation to an

antecedent state, is a mere modification of this second hypothesis.

The third hypothesis also assumes that the present state of things has

had but a limited duration; but it Supposes that this state has been

evolved by a natural process from an antecedent state, and that from

another, and so on; and, on this hypothesis, the attempt to assign any

limit to the series of past changes is, usually, given up.

It is so needful to form clear and distinct notions of what is really

meant by each of these hypotheses that I will ask you to imagine what,

according to each, would have been visible to a spectator of the events

which constitute the history of the earth. On the first hypothesis,

however far back in time that spectator might be placed, he would see a

world essentially, though perhaps not in all its details, similar to

that which now exists. The animals which existed would be the ancestors

of those which now live, and similar to them; the plants, in like

manner, would be such as we know; and the mountains, plains, and waters

would foreshadow the salient features of our present land and water.

This view was held more or less distinctly, sometimes combined with the

notion of recurrent cycles of change, in ancient times; and its

influence has been felt down to the present day. It is worthy of remark

that it is a hypothesis which is not inconsistent with the doctrine of

Uniformitarianism, with which geologists are familiar. That doctrine was

held by Hutton, and in his earlier days by Lyell. Hutton was struck by

the demonstration of astronomers that the perturbations of the planetary

bodies, however great they may be, yet sooner or later right themselves;

and that the solar system possesses a self-adjusting power by which

these aberrations are all brought back to a mean condition. Hutton

imagined that the like might be true of terrestrial changes; although no

one recognized more clearly than he the fact that the dry land is being

constantly washed down by rain and rivers and deposited in the sea; and

that thus, in a longer or shorter time, the inequalities of the earth's

surface must be leveled, and its high lards brought down to the ocean.

But, taking into account the internal forces of the earth, which,

upheaving the sea bottom, give rise to new land, he thought that these

operations of degradation and elevation might compensate each other: and

that thus, for any assignable time, the general features of our planet

might remain what they are. And inasmuch as, under these circumstances,

there need be no limit to the propagation of animals and plants, it is

clear that the consistent working out of the uniformitarian idea might

load to the conception of the eternity of the world. Not that I mean to

say that either Hutton or Lyell held this conception--assuredly not;

they would have been the first to repudiate it. Nevertheless, the

logical development of their arguments lends directly towards this

hypothesis.

The second hypothesis supposes that the present order of things, at some

no very remote time, had a sudden origin, and that the world, such as it

now is, had chaos for its phenomenal antecedent. That is the doctrine

which you will find stated most fully and clearly in the immortal poem

of John Milton,--the English _Divina Commedia,_--"Paradise Lost." I

believe it is largely to the influence of that remarkable work, combined

with the daily teachings to which we have all listened in our childhood,

that this hypothesis owes its general wide diffusion as one of the

current beliefs of English-speaking people. If you turn to the seventh

book of "Paradise Lost," you will find there stated the hypothesis to

which I refer, which is briefly this: That this visible universe of ours

came into existence at no great distance of time from the present; and

that the parts of which it is composed made their appearance, in a

certain, definite order, in the space of six natural days, in such a

manner that, on the first of these days, light appeared; that, on the

second, the firmament, or sky, separated the waters above, from the

waters beneath the firmament; that, on the third day, the waters drew

away from the dry land, and upon it a varied vegetable life, similar to

that which now exists, made its appearance; that the fourth day was

signalized by the apparition of the sun, the stars, the moon, and the

planets; that, on the fifth day, aquatic animals originated within the

waters; that, on the sixth day, the earth gave rise to our four-footed

terrestrial creatures, and to all varieties of terrestrial animals

except birds, which had appeared on the preceding day; and, finally,

that man appeared upon the earth, and the emergence of the universe from

chaos was finished. Milton tells us, without the least ambiguity, what a

spectator of these marvelous occurrences would have witnessed. I doubt

not that his poem is familiar to all of you, but I should like to recall

one passage to your minds, in order that I may be justified in what I

have said regarding the perfectly concrete, definite picture of the

origin of the animal world which Milton draws. He says:

"The sixth, and of creation last, arose

With evening harps and matin, when God said,

'Let tine earth bring forth soul living in her kind,

Cattle and creeping things, and beast of the earth,

Each in their kind!' The earth obeyed, and, straight

Opening her fertile womb, teemed at a birth.

Innumerous living creatures, perfect forms,

Limbed and full-grown. Out of the ground uprose,

As from his lair, the wild beast, where he wons

In forest wild, in thicket, brake, or den:

Among the trees in pairs they rose, they walked;

The cattle in the fields and meadows green;

Those rare and solitary; these in flocks

Pasturing at once, and in broad herds upsprung.

The grassy clods now calved; now half appears

The tawny lion, pawing to get free

His hinder parts--then springs, as broke from bonds,

And rampant shakes his brinded mane; the ounce,

The libbard, and the tiger, as the mole

Rising, the crumbled earth above them threw

In hillocks; the swift stag from underground

Bore up his branching head; scarce from his mould

Behemoth, biggest born of earth, upheaved

His vastness; fleeced the flocks and bleating rose

As plants; ambiguous between sea and land,

The river-horse and scaly crocodile.

At once came forth whatever creeps the ground,

Insect or worm."

There is no doubt as to the meaning of this statement, nor as to what a

man of Milton's genius expected would have been actually visible to an

eyewitness of this mode of origination of living things.

The third hypothesis, or the hypothesis of evolution, supposes that, at

any comparatively late period of past time, our imaginary spectator

would meet with a state of things very similar to that which now

obtains; but that the likeness of the past to the present would

gradually become less and less, in proportion to the remoteness of his

period of observation from the present day: that the existing

distribution of mountains and plains, of rivers and seas, would show

itself to be the product of a slow process of natural change operating

upon more and more widely different antecedent conditions of the mineral

framework of the earth; until, at length, in place of that framework, he

would behold only a vast nebulous mass, representing the constituents of

the sun and of the planetary bodies. Preceding the forms of life which

now exist, our observer would see animals and plants not identical with

them, but like them: increasing their differences with their antiquity,

and at the same time becoming simpler and simpler; until, finally, the

world of life would present nothing but that undifferentiated

protoplasmic matter which, so far as our present knowledge goes, is the

common foundation of all vital activity.

The hypothesis of evolution supposes that in all this vast progression

there would be no breach of continuity, no point at which we could say

"This is a natural process," and "This is not a natural

process"; but

that the whole might be compared to that wonderful process of

development which may be seen going on every day under our eyes, in

virtue of which there arises, out of the semifluid, comparatively

homogeneous substance which we call an egg, the complicated organization

of one of the higher animals. That, in a few words, is what is meant by

the hypothesis of evolution.

* * * * *

I have already suggested that in dealing with these three hypotheses, in

endeavoring to form a judgment as to which of them is the more worthy of

belief, or whether none is worthy of belief--in which case our

condition of mind should be that suspension of judgment which is so

difficult to all but trained intellects,--we should be indifferent to

all _a priori_ considerations. The question is a question of historical

fact. The universe has come into existence somehow or other, and the

problem is, whether it came into existence in one fashion, or whether it

came into existence in another; and, as an essential preliminary to

further discussion, permit me to say two or three words as to the nature

and the kinds of historical evidence.

The evidence as to the occurrence of any event in past time may be

ranged under two heads, which, for convenience' sake, I will speak of as

testimonial evidence and as circumstantial evidence. By testimonial

evidence I mean human testimony; and by circumstantial evidence I mean

evidence which is not human testimony. Let me illustrate by a familiar

example what I understand by these two kinds of evidence, and what is to

be said respecting their value.

Suppose that a man tells you that he saw a person strike another and

kill him; that is testimonial evidence of the fact of murder. But it is

possible to have circumstantial evidence of the fact of murder; that is

to say, you may find a man dying with a wound upon his head having

exactly the form and character of the wound which is made by an ax, and,

with due care in taking surrounding circumstances into account, you may

conclude with the utmost certainty that the man has been murdered; that

his death is the consequence of a blow inflicted by another man with

that implement. We are very much in the habit of considering

circumstantial evidence as of less value than testimonial evidence, and

it may be that, where the circumstances are not perfectly clear and

intelligible, it is a dangerous and unsafe kind of evidence; but it must

not be forgotten that, in many cases, circumstantial evidence is quite

as conclusive as testimonial evidence, and that, not unfrequently, it is

a great deal weightier than testimonial evidence. For example, take the

case to which I referred just now. The circumstantial evidence may be

better and more convincing than the testimonial evidence; for it may be

impossible, under the conditions that I have defined, to suppose that

the man met his death from any cause but the violent blow of an ax

wielded by another man. The circumstantial evidence in favor of a murder

having been committed, in that case, is as complete and as convincing as

evidence can be. It is evidence which is open to no doubt and to no

falsification. But the testimony of a witness is open to multitudinous

doubts. He may have been mistaken. He may have been actuated by malice.

It has constantly happened that even an accurate man has declared that a

thing has happened in this, that, or the other way, when a careful

analysis of the circumstantial evidence has shown that it did not happen

in that way, but in some other way.

We may now consider the evidence in favor of or against the three

hypotheses. Let me first direct your attention to what is to be said

about the hypothesis of the eternity of the state of things in which we

now live. What will first strike you is, that it is a hypothesis which,

whether true or false, is not capable of verification by any evidence.

For, in order to obtain either circumstantial or testimonial evidence

sufficient to prove the eternity of duration of the present state of

nature, you must have an eternity of witnesses or an infinity of

circumstances, and neither of these is attainable. It is utterly

impossible that such evidence should be carried beyond a certain point

of time; and all that could be said, at most, would be, that so far as

the evidence could be traced, there was nothing to contradict the

hypothesis. But when you look, not to the testimonial evidence--which,

considering the relative insignificance of the antiquity of human

records, might not be good for much in this case--but to the

circumstantial evidence, then you will find that this hypothesis is

absolutely incompatible with such evidence as we have; which is of so

plain and so simple a character that it is impossible in any way to

escape from the conclusions which it forces upon us.

You are, doubtless, all aware that the outer substance of the earth,

which alone is accessible to direct observation, is not of a homogeneous

character, but that it is made up of a number of layers or strata, the

titles of the principal groups of which are placed upon the

accompanying diagram.[68] Each of these groups represents a number of

beds of sand, of stone, of clay, of slate, and of various other

materials.

On careful examination, it is found that the materials of which each of

these layers of more or less hard rock are composed are, for the most

part, of the same nature as those which are at present being formed

under known conditions on the surface of the earth. For example, the

chalk, which constitutes a great part of the Cretaceous formation in

some parts of the world, is practically identical in its physical and

chemical characters with a substance which is now being formed at the

bottom of the Atlantic Ocean, and covers an enormous area; other beds of

rock are comparable with the sands which art; being formed upon

seashores, packed together, and so on. Thus, omitting rocks of igneous

origin, it is demonstrable that all these beds of stone, of which a

total of not less than seventy thousand feet is known, have been formed

by natural agencies, either out of the waste and washing of the dry

land, or else by the accumulation of the exuviae of plants and animals.

Many of these strata are full of such exuviae--the so-called

"fossils."

Remains of thousands of species of animals and plants, as perfectly

recognizable as those of existing forms of life which you meet with in

museums, or as the shells which you pick up upon the seabeach, have been

embedded in the ancient sands, or muds, or limestones, just as they are

being embedded now, in sandy, or clayey, or calcareous subaqueous

deposits. They furnish us with a record, the general nature of which

cannot be misinterpreted, of the kinds of things that have lived upon

thy surface of the earth during the time that is registered by this

great thickness of stratified rocks. But even a superficial study of

these fossils shows us that the animals and plants which live at the

present time have had only a temporary duration; for the remains of such

modern forms of life are met with, for the most part, only in

the uppermost or latest tertiaries, and their number rapidly diminishes

in the lower deposits of that epoch. In the older tertiaries, the places

of existing animals and plants are taken by other forms, as numerous and

diversified as those which live now in the same localities, but more or

less different from them; in the Mesozoic rocks, these are replaced by

others yet more divergent from modern types; and in the Paleozoic

formations the contrast is still more marked. Thus the circumstantial

evidence absolutely negatives the conception of the eternity of the

present condition of things. We can say with certainly that the present

condition of things has existed for a comparatively short period; and

that, so far as animal and vegetable nature are concerned, it has been

preceded by a different condition. We can pursue this evidence until we

reach the lowest of the stratified rocks, in which we lose the

indications of life altogether. The hypothesis of the eternity of the

present state of nature may therefore be put out of court.

We now come to what I will term Milton's hypothesis--the hypothesis that

the present condition of things has endured for a comparatively short

time; and, at the commencement of that time, came into existence within

the course of six days. I doubt not that it may have excited some

surprise in your minds that I should have spoken of this as Milton's

hypothesis, rather than that I should have chosen the terms which are

more customary, such as "the doctrine of creation," or the "Biblical

doctrine," or "the doctrine of Moses," all of which denominations, as

applied to the hypothesis to which I have just referred, are certainly

much more familiar to you than the title of the Miltonic hypothesis. But

I have had what I cannot but think are very weighty reasons for taking

the course which T have pursued. In the first place, I have discarded

the title of the doctrine of "creation," because my present business is

not with the question why the objects which constitute Nature came into

existence, but when they came into existence, and in what order. This is

as strictly a historical question as the question when the Angles and

the Jutes invaded England, and whether they preceded or followed the

Romans. But the question about creation is a philosophical problem, and

one which cannot be solved, or even approached, by the historical

method. What we want to learn is, whether the facts, so far as they are

known, afford evidence that things arose in the way described-by Milton,

or whether they do not; and, when that question is settled, it will be

time enough to inquire into the causes of their origination.

In the second place, I have not spoken of this doctrine as the Biblical

doctrine, It is quite true that persons as diverse in their general

views as Milton the Protestant and the celebrated Jesuit Father Suarez,

each put upon the first chapter of Genesis the interpretation embodied

in Milton's poem. It is quite true that this interpretation is that

which has been instilled into every one of us in our childhood; but I do

not for one moment venture to say that it can properly be called the

Biblical doctrine. It is not my business, and does not lie within my

competency, to say what the Hebrew text does, and what it does not

signify; moreover, were I to affirm that this is the Biblical doctrine,

I should be met by the authority of many eminent scholars, to say

nothing of men of science, who, at various times, have absolutely denied

that any such doctrine is to be found in Genesis. If we are to listen to

many expositors of no mean authority, we must believe that what seems so

clearly defined in Genesis--as if very great pains had been taken that

there should be no possibility of mistake--is not the meaning of the

text at all. The account is divided into periods that we may make just

as long or short as convenience requires. We are also to understand that

it is consistent with the original text to believe that the most complex

plants and animals may have been evolved by natural processes, lasting

for millions of years, out of structureless rudiments. A person who is

not a Hebrew scholar can only stand aside and admire the marvelous

flexibility of a language which admits of such diverse interpretations.

But assuredly, in the face of such contradictions of authority upon

matters respecting which he is incompetent to form any judgment, he will

abstain, as I do, from giving any opinion.

In the third place, I have carefully abstained from speaking of this as

the Mosaic doctrine, because we are now assured upon the authority of

the highest critics, and even of dignitaries of the Church, that there

is no evidence that Moses wrote the Book of Genesis, or knew anything

about it. You will understand that I give no judgment--it would be an

impertinence upon my part to volunteer even a suggestion--upon such a

subject. But, that being the state of opinion among the scholars and the

clergy, it is well for the unlearned in Hebrew lore, and for the laity,

to avoid entangling themselves in such a vexed question. Happily, Milton

leaves us no excuse for doubting what he means, and I shall therefore be

safe in speaking of the opinion in question as the Miltonic hypothesis.

Now we have to test that hypothesis. For my part, I have no prejudice

one way or the other. If there is evidence in favor of this view, I am

burdened by no theoretical difficulties in the way of accepting it: but

there must be evidence. Scientific men get an awkward habit--no, I won't

call it that, for it is a valuable habit--of believing nothing unless

there is evidence for it; and they have a way of looking upon belief

which is not based upon evidence, not only as illogical, but as immoral.

We will, if you please, test this view by the circumstantial evidence

alone; for, from what I have said, you will understand that I do not

propose to discuss the question of what testimonial evidence is to be

adduced in favor of it. If those whose business it is to judge are not

at one as to the authenticity of the only evidence of that kind which is

offered, nor as to the facts to which it bears witness, the discussion

of such evidence is superfluous.

But I may be permitted to regret this necessity of rejecting the

testimonial evidence the less, because the examination of the

circumstantial evidence leads to the conclusion, not only that it is

incompetent to justify the hypothesis, but that, so far as it goes, it

is contrary to the hypothesis.

The considerations upon which I base this conclusion are of the simplest

possible character. The Miltonic hypothesis contains assertions of a

very definite character relating to the succession of living forms. It

is stated that plants, for example, made their appearance upon the third

day, and not before. And you will understand that what the poet means

by plants are such plants as now live, the ancestors, in the ordinary

way of propagation of like by like, of the trees and shrubs which

flourish in the present world. It must needs be so; for, if they were

different, either the existing plants have been the result of a separate

origination since that described by Milton, of which we have no record,

nor any ground for supposition that such an occurrence has taken place;

or else they have arisen by a process of evolution from the original

stocks.

In the second place, it is clear that there was no animal life before

the fifth day, and that, on the fifth day, aquatic animals and birds

appeared. And. it is further clear that terrestrial living things, other

than birds, made their appearance upon the sixth day, and not before.

Hence, it follows that, if, in the large mass of circumstantial evidence

as to what really has happened in the past history of the globe, we find

indications of the existence of terrestrial animals, other than birds,

at a certain period, it is perfectly certain that all that has taken

place since that time must be referred to the sixth day.

In the great Carboniferous formation,[69] whence America derives so vast

a proportion of her actual and potential wealth, in the beds of coal

which have been formed from the vegetation of that period, we find

abundant evidence of the existence of terrestrial animals. They have

been described, not only by European but by your own naturalists. There

are to be found numerous insects allied to our cockroaches. There are to

be found spiders and scorpions of large size, the latter so similar to

existing scorpions that it requires the practiced eye of the naturalist

to distinguish them. Inasmuch as these animals can be proved to have

been alive in the Carboniferous epoch, it is perfectly clear that, if

the Miltonic account is to be accepted, the huge mass of rocks extending

from the middle of the Paleozoic formations to the uppermost members of

the series, must belong to the day which is termed by Milton the sixth.

But, further, it is expressly stated that aquatic animals took their

origin upon the fifth day, and not before; hence, all formations in

which remains of aquatic animals can be proved to exist, and which

therefore testify that such animals lived at the time when these

formations were in course of deposition, must have been deposited during

or since the period which Milton speaks of as the fifth. But there is

absolutely no fossiliferous formation in which the remains of aquatic

animals are absent. The oldest fossils in the Silurian rocks[70] are

exuviae of marine animals; and if the view which is entertained by

Principal Dawson and Dr. Carpenter respecting the nature of the _eozoön_

be well founded, aquatic animals existed at a period as far antecedent

to the deposition of the coal as the coal is from us; inasmuch as the

_eozoön_ is met with in those Laurentian strata which lie at the bottom

of the series of stratified rocks. Hence it follows, plainly enough,

that the whole series of stratified rocks, if they are to be brought

into harmony with Milton, must be referred to the fifth and sixth days,

and that we cannot hope to find the slightest trace of the products of

the earlier days in the geological record. When we consider these simple

facts, we see how absolutely futile are the attempts that have been made

to draw a parallel between the story told by so much of the crust of the

earth as is known to us and the story which Milton tells. The whole

series of fossiliferous stratified rocks must be referred to the last

two days; and neither the Carboniferous, nor any other, formation can

afford evidence of the work of the third day.

Not only is there this objection to any attempt to establish a harmony

between the Miltonic account and the facts recorded in the fossiliferous

rocks, but there is a further difficulty. According to the Miltonic

account, the order in which animals should have made their appearance in

the stratified rocks would be this: Fishes, including the great whales,

and birds; after them, all varieties of terrestrial animals except

birds.

Nothing could be further from the facts as we find them; we know of not

the slightest evidence of the existence of birds before the Jurassic, or

perhaps the Triassic, formation;[71] while terrestrial animals, as we

have just seen, occur in the Carboniferous rocks.

If there were any harmony between the Miltonic account and the

circumstantial evidence, we ought to have abundant evidence of the

existence of birds in the Carboniferous, the Devonian, and the Silurian

rocks. I need hardly say that this is not the case, and that not a trace

of birds makes its appearance until the Tar later period which I have

mentioned.

And again, if it be true that all varieties of fishes and the great

whales, and the like, made their appearance on the fifth day, we ought

to find the remains of these animals in the older rocks--in those which

were deposited before the Carboniferous epoch. Fishes we do find, in

considerable number and variety; but the great whales are absent, and

the fishes are not such as now live. Not one solitary species of fish

now in existence is to be found in the Devonian or Silurian formations.

Hence we are introduced afresh to the dilemma which I have already

placed before you: either the animals which came into existence on the

fifth day were not such as those which are found at present, are not the

direct and immediate ancestors of those which now exist; in which case

either fresh creations of which nothing is said, or a process of

evolution must have occurred; or else the whole story must be given up

as not only devoid of any circumstantial evidence, but contrary to such

evidence as exists.

I placed before you in a few words, some little time ago, a statement of

the sum and substance of Milton's hypothesis. Let me now try to state as

briefly, the effect of the circumstantial evidence bearing upon the past

history of the earth which is furnished, without the possibility of

mistake, with no chance of error as to its chief features, by the

stratified rocks. What we find is, that the great series of formations

represents a period of time of which our human chronologies hardly

afford us a unit of measure. I will not pretend to say how we ought to

estimate this time, in millions or in billions of years. For my purpose,

the determination of its absolute duration is wholly unessential. But

that the time was enormous there can be no question.

It results from the simplest methods of interpretation, that leaving out

of view certain patches of metamorphosed rocks, and certain volcanic

products, all that is now dry land has once been at the bottom of the

waters. It is perfectly certain that, at a comparatively recent period

of the world's history--the Cretaceous epoch--none of the great physical

features which at present mark the surface of the globe existed. It is

certain that the Rocky Mountains were not. It is certain that the

Himalaya Mountains were not. It is certain that the Alps and the

Pyrenees had no existence. The evidence is of the plainest possible

character, and is simply this:--We find raised up on the flanks of these

mountains, elevated by the forces of upheaval which have given rise to

them, masses of Cretaceous rock which formed the bottom of the sea

before those mountains existed. It is therefore clear that the elevatory

forces which gave rise to the mountains operated subsequently to the

Cretaceous epoch; and that the mountains themselves are largely made up

of the materials deposited in the sea which once occupied their place.

As we go back in time, we meet with constant alternations of sea and

land, of estuary and open ocean; and, in correspondence with these

alternations, we observe the changes in the fauna and flora to which I

have referred.

But the inspection of these changes gives us no right to believe that

there has been any discontinuity in natural processes. There is no trace

of general cataclysms, of universal deluges, or sudden destructions of a

whole fauna or flora. The appearances which were formerly interpreted in

that way have all been shown to be delusive, as our knowledge has

increased and as the blanks which formerly appeared to exist between the

different formations have been filled up. That there is no absolute

break between formation and formation, that there has been no sudden

disappearance of all the forms of life and replacement of them by

others, but that changes have gone on slowly and gradually, that one

type has died out and another has taken its place, and that thus, by

insensible degrees, one fauna has been replaced by another, are

conclusions strengthened by constantly increasing evidence. So that

within the whole of the immense period indicated by the fossiliferous

stratified rocks, there is assuredly not the slightest proof of any

break in the uniformity of Nature's operations, no indication that

events have followed other than a clear and orderly sequence.

That, I say, is the natural and obvious teaching of the circumstantial

evidence contained in the stratified rocks. I leave you to consider how

far, by any ingenuity of interpretation, by any stretching of the

meaning of language, it can be brought into harmony with the Miltonic

hypothesis.

There remains the third hypothesis, that of which I have spoken as the

hypothesis of evolution; and I purpose that, in lectures to come, we

should discuss it as carefully as we have considered the other two

hypotheses. I need not say that it is quite hopeless to look for

testimonial evidence of evolution. The very nature of the case precludes

the possibility of such evidence, for the human race can no more be

expected to testify to its own origin, than a child can be tendered as a

witness of its own birth. Our sole inquiry is, what foundation

circumstantial evidence lends to the hypothesis, or whether it lends

none, or whether it controverts the hypothesis. I shall deal with the

matter entirely as a question of history. I shall not indulge in the

discussion of any speculative probabilities. I shall not attempt to show

that Nature is unintelligible unless we adopt some such hypothesis. For

anything I know about the matter, it may be the way of Nature to be

unintelligible; she is often puzzling, and I have no reason to suppose

that she is bound to fit herself to our notions.

I shall place before you three kinds of evidence entirely based upon

what is known of the forms of animal life which are contained in the

series of stratified rocks. I shall endeavor to show you that there is

one kind of evidence which is neutral, which neither helps evolution nor

is inconsistent with it. I shall then bring forward a second kind of

evidence which indicates a strong probability in favor of evolution, but

does not prove it; and, lastly, I shall adduce a third kind of evidence

which, being as complete as any evidence which we can hope to obtain

upon such a subject, and being wholly and strikingly in favor of

evolution, may fairly be called demonstrative evidence of its

occurrence.

THE TRANSMISSION OF YELLOW FEVER BY MOSQUITOES

GEORGE M. STERNBERG, M.D., L.L.D, SURGEON-GENERAL U.S. ARMY[72]

This article is a scientific demonstration of a new fact. It shows

clearly the processes of scientific reasoning based on the methods known

to Logic as the Methods of Agreement and Difference. The theory that the

germs of the disease are carried by mosquitoes seems first to have

suggested itself to Dr. Sternberg and to Dr. Finlay through noticing a

similarity of phenomena in many cases under different conditions. Yet,

however plausible, the theory, neither of them could declare that he had

discovered the fact until the experiments carried on under rigorous

precautions had been tried. By these experiments all other causes were

ruled out of consideration.

The discoveries which have been made in the past twenty-five years with

reference to the etiology[73] of infectious diseases constitute the

greatest achievement of scientific medicine and afford a substantial

basis for the application of intelligent measures of prophylaxis.[74] We

know the specific cause ("germ") of typhoid fever, of pulmonary

consumption, of cholera, of diphtheria, of erysipelas, of croupous

pneumonia, of the malarial fevers, and of various other infectious

diseases of man and of the domestic animals, but, up to the present

time, all efforts to discover the germ of yellow fever have been without

success. The present writer, as a member of the Havana Yellow Fever

Commission, in 1879, made the first systematic attempt to solve the

unsettled questions relating to yellow fever etiology by modern methods

of research.

Naturally the first and most important question to engage my attention

was that relating to the specific infectious agent, or "germ," which

there was every reason to believe must be found in the bodies of

infected individuals. Was this germ present in the blood, as in the case

of relapsing fever; or was it to be found in the organs and tissues

which upon post-mortem examination give evidence of pathological

changes, as in typhoid fever, pneumonia, and diphtheria; or was it to be

found in the alimentary canal, as in cholera and dysentery?

The clinical history of the disease indicated a general blood

infection. As my equipment included the best microscopical apparatus

made, I had strong hopes that in properly stained preparations of blood

taken from the circulation of yellow fever patients my Zeiss 1-18 oil

immersion objective would reveal to me the germ I was in search of. But

I was doomed to disappointment. Repeated examinations of blood from

patients in every stage of the disease failed to demonstrate the

presence of microorganisms of any kind. My subsequent investigations in

Havana, Vera Cruz, and Rio de Janeiro, made in 1887, 1888, and 1889,

were equally unsuccessful. And numerous competent microscopists of

various nations have since searched in vain for this elusive germ.

Another method of attacking this problem consists in introducing blood

from yellow fever patients or recent cadavers into various "culture

media" for the purpose of cultivating any germ that might be present.

Extended researches of this kind also gave a negative result, which in

my final report I stated as follows:

The specific cause of yellow fever has not yet been demonstrated.

It is demonstrated that microorganisms, capable of development in

the culture media usually employed by the bacteriologists, are only

found in the blood and tissues of yellow fever cadavers in

exceptional cases, when cultures are made very soon after death.

Since this report was made, various investigators have attacked the

question of yellow fever etiology, and one of them has made very

positive claims to the discovery of the specific germ. I refer to the

Italian bacteriologist, Sanarelli. His researches were made in Brazil,

and, singularly enough, he found in the blood of the first case examined

by him a bacillus. It was present in large numbers, but this case

proved to be unique, for neither Sanarelli nor any one else has since;

found it in such abundance. It has been found in small numbers in the

blood and tissues of yellow fever cadavers in a certain number of the

cases examined. But carefully conducted researches by competent

bacteriologists have failed to demonstrate its presence in a

considerable proportion of the cases, and the recent researches of Reed,

Carroll, and Agramonte, to which I shall shortly refer, demonstrate

conclusively that the bacillus of Sanarelli has nothing to do with the

etiology of yellow fever.

So far as I am aware, Dr. Carlos Finlay, of Havana, Cuba, was the first

to suggest the transmission of yellow fever by mosquitoes. In a

communication made to the Academy of Sciences of Havana, in October,

1881, he gave an account of his first attempts to demonstrate the truth

of his theory. In a paper contributed to _The Edinburgh Medical Journal_

in 1894, Dr. Finlay gives a summary of his experimental inoculations up

to that date as follows:

A summary account of the experiments performed by myself (and some also

by my friend, Dr. Delgado), during the last twelve years, will enable

the reader to judge for himself. The experiment has consisted in first

applying a captive mosquito to a yellow fever patient, allowing it to

introduce its lance and to fill itself with blood; next, after the lapse

of two or more days, applying the same mosquito to the skin of a person

who is considered susceptible to yellow fever: and, finally, observing

the effects, not only during the first two weeks, but during periods of

several years, so as to appreciate the amount of immunity that should

follow.

Between the 30th of June, 1881, and the 2d of December, 1893,

eighty-eight persons have been so inoculated. All were white adults,

uniting the conditions which justify the assumption that they were

susceptible to yellow fever. Only three were women. The chronological

distribution of the inoculations was as follows: seven in 1881, ten in

1883, nine in 1885, three in 1886, twelve in 1887, nine in 1888, seven

in 1889, ten in 1890, eight in 1891, three in 1892, and ten in 1893.

The yellow fever patients upon whom the mosquitoes were contaminated

were, almost in every instance, well-marked cases of the albuminuric or

melanoalbuminuric forms, in the second, third, fourth, fifth, or sixth

day of the disease. In some of the susceptible subjects, the inoculation

was repeated when the source of the contamination appeared uncertain.

Among the eighty-seven who have been under observation, the following

results have been recorded:

Within a term of days, varying between five and twenty-five after the

inoculation, _one_ presented a mild albuminuric attack, and _thirteen,

only_ "acclimation fevers."

* * * * *

While Finlay's theory appeared to be plausible and to explain many of

the facts relating to the etiology of yellow fever, his experimental

inoculations not only failed to give it substantial support, but the

negative results, as reported, by himself, seemed to be opposed to the

view that yellow fever is transmitted by the mosquito. It is true that

he reports one case which "presented a mild albuminuric attack" which we

may accept as an attack of yellow fever. But in view of the fact that

this case occurred in the city of Havana, where yellow fever is endemic,

and of the eighty-six negative results from similar inoculations, the

inference seemed justified that in this case the disease was contracted

in some other way than as a result of the so-called "mosquito

inoculation." The thirteen cases in which only "acclimation fevers"

occurred "within a term of days varying between five and twenty-five

after the inoculation" appeared to me to have no value as giving support

to Finlay's theory; first, because these "acclimation fevers" could not

be identified as mild cases of yellow fever; second, because the

ordinary method of incubation in yellow fever, is less than five days;

and, third, because these individuals, having recently arrived in

Havana, were liable to attacks of yellow fever, or of "acclimation

fever" as a result of their residence in this city and quite

independently of Dr. Finlay's mosquito inoculations. For these reasons

Dr. Finlay's experiments failed to convince the medical profession

generally of the truth of his theory relating to the transmission of

yellow fever, and this important question remained in doubt and a

subject of controversy. One party regarded the disease as personally

contagious and supposed it to be communicated directly from the sick to

the well, as in the case of other contagious diseases, such as smallpox,

scarlet fever, etc. Opposed to this theory was the fact that in

innumerable instances nonimmune persons had been known to care for

yellow-fever patients as nurses, or physicians, without contracting the

disease; also the fact that the epidemic extension of the disease

depends upon external conditions relating to temperature, altitude,

rainfall, etc. It was a well-established fact that the disease is

arrested by cold weather and does not prevail in northern latitudes or

at considerable altitudes. But diseases which are directly transmitted

from man to man by personal contact have no such limitations. The

alternate theory took account of the above-mentioned facts and assumed

that the disease was indirectly transmitted from sick to well, as is the

case in typhoid fever and cholera, and that its germ was capable of

development external to the human body when conditions were favorable.

These conditions were believed to be a certain elevation of the

temperature, the presence of moisture and suitable; organic pabulum

(filth) for the development of the germ. The two first-mentioned

conditions were known to be essential, the third was a subject of

controversy.

Yellow fever epidemics do not occur in the winter months in the

temperate zone and they do not occur in arid regions. As epidemics have

frequently prevailed in seacoast cities known to be in an insanitary

condition, it has been generally assumed that the presence of

decomposing organic material is favorable for the development of an

epidemic and that, like typhoid fever and cholera, yellow fever is a

"filth disease." Opposed to this view, however, is the fact that

epidemics have frequently occurred in localities (e.g. at military

posts) where no local insanitary conditions were to be found. Moreover,

there are marked differences in regard to the transmission of the

recognized filth diseases--typhoid fever and cholera--and yellow fever.

The first-mentioned diseases are largely propagated by means of a

contaminated water supply, whereas there is no evidence that yellow

fever is ever communicated in this way. Typhoid fever and cholera

prevail in all parts of the world and may prevail at any season of the

year, although cholera, as a rule, is a disease of the summer months. On

the other hand, yellow fever has a very restricted area of prevalence

and is essentially a disease of seaboard cities and of warm climates.

Evidently neither of the theories referred to accounts for all of the

observed facts with reference to the endemic prevalence and epidemic

extension of the disease under consideration.