Some of the letters from clergymen which have been called out by our
article on the part recently taken by them in scientific discussion
maintain that, although ministers may not be familiar with the facts
of science, many of them are fully competent to weigh the arguments
founded on these facts put forward by scientific men, and decide
whether they have proved their case or not; or, in other words, that
we were mistaken in saying that the theological seminaries did not
afford severe training in the use of the inductive process, and that
it could not be used effectively without knowledge of the matters on
which it was used. More than one of these letters points, in support
of this view, to the answer of the Rev. Dr. Taylor, of this city,
to Professor Huxley's lectures, published some weeks ago in the
_Tribune_, and we believe the _Tribune_ presented the author to the
public as "a trained logician."
We have accordingly turned to Dr. Taylor's letter and given it a
much more attentive reading than we confess we gave it when it first
appeared, for the purpose of seeing whether it was really true that
ministers were such dexterous and highly taught dialecticians that
they could overthrow a scientific man, even on a subject of which
they knew little or nothing--whether, in short, they could really
treat the question of evolution algebraically, and, by the mere aid
of signs of the meaning of which they were ignorant, put the Huxleys
and Darwins to confusion. For Dr. Taylor opens in this way:
"Let it be understood, then, that I have no fault to find with
Mr. Huxley as a discoverer of facts or as an exponent of
comparative anatomy. In both of these respects he is beyond all
praise of mine, and I am ready to sit at his feet; but when he
begins to reason from the facts which he sets forth, then, like
every other reasoner, he is amenable to the laws of
argumentation, and his conclusions are to be tested by the
relation which they bear to the premises which he has advanced,
and by the proof which he furnishes for the premises
themselves."
We pass over, as of no consequence for our present purpose, the
various exceptions which he then takes to Huxley's arrangement of
his lectures, to the tone of his exceptions, and to his mode of
referring to the biblical hypothesis, and come to what he has to say
of Huxley's evidence, which he truly calls "circumstantial
evidence." The first thing he does is to define circumstantial
evidence; but here, at the very outset, we have been surprised to
find a logician who conceives himself capable of overhauling the
argumentation of the masters of science, going to a lawyer to get
"a statement of the principles which regulate the value of
circumstantial evidence." This is a matter which lay logicians
usually have at their fingers' ends, and we have never known one yet
who would not be puzzled by a suggestion that he should do as Dr.
Taylor did--go to a "distinguished legal friend" for information as
to the conditions of this kind of proof. For, as we have more than
once pointed out, lawyers, as such, have no special skill or
training in the use of circumstantial evidence as scientific men
know it--that is, as evidence which derives all its force from
the laws of the human mind. The circumstantial evidence with
which lawyers, _quâ_ lawyers, are familiar under our system of
jurisprudence is an artificial thing created by legislation or
custom, with the object of preventing the minds of the jury--
presumably a body of untrained and unlearned men--from being
confused or led astray. Moreover, they are only familiar with its
use in one very narrow field--human conduct under one set of social
conditions. For example, a lawyer might be a very good judge of
circumstantial evidence in America, and a very poor one in India or
China; might have a keen eye for the probable or improbable in a New
England village, and none at all in a Prussian barrack.
A familiar illustration of the restrictions on his experience of it
is to be found in the rule which compels the calling of "experts"
when there is a question as to any point of science or art. "The
words science or art," says Mr. Fitzjames Stephen, "include all
subjects on which a _course of special study or experience is
necessary to the formation of an opinion_," and the opinion of such
an expert is a "relevant fact." So that Dr. Taylor's "distinguished
legal friend," if a good lawyer, would not, in spite of his
proficiency in circumstantial evidence, undertake to dispute with
Professor Huxley about the relation of the anchitherium, hipparion,
and horse; and if Dr. Taylor offered himself for examination on such
a point he would be laughed out of court. In none of our courts is
the presentation allowed of _all_ the circumstances which strengthen
or weaken a probability.
A lawyer, therefore, though he might not be as ill fitted for a
scientific discussion as a minister, is, _as such_, hardly more of
an authority on the force and limits of that portion of scientific
proof which is drawn from simple observation. Dr. Taylor's
consulting one as a final authority as to the very nature of the
argument on which he was himself about to sit in judgment is at the
outset a suspicious incident. The definition of circumstantial
evidence which he got from his legal friend was this:
"The process of proof by circumstantial evidence consists in
reasoning from such facts as are known or proved, and thence
establishing such as are conjectured to exist. The process is
fatally vicious, first, if any material circumstance from which
we seek to deduce the conclusion depends itself on conjecture;
and, second, if the known facts are not such as to exclude to a
reasonable degree of certainty every other hypothesis."
"Now, tried by these two tests," says Dr. Taylor, "the professor's
argument was a failure." Taking this definition as it stands,
however, we think it will not be difficult to show that Dr. Taylor
is not competent to apply the tests, or to say whether the
professor's argument is a failure or not.
It is hardly necessary to say that all the evidence in our
possession or attainable, with regard to the history of the earth
and of animal and vegetable life on its surface, is circumstantial
evidence. The sciences of geology, palaeontology, and, to a certain
extent, biology are sciences of observation, and but few of their
conclusions can be reached or tested by experimentation. They are
the result of a collection of facts, observed in various places, at
various times, and by various persons, and variously related to
other facts; and the collection of these facts, and the arrangement
of them, and the formation of a judgment as to their value both
positive and relative, form the greater portion of the work of a
scientific man in these fields. Professor Huxley's argument, which
Dr. Taylor disposes of so summarily, consists of a series of
inferences from facts so collected and arranged. They are the things
"known or proved," on which, as his legal friend truly says, the
reasoning in the process of proof by circumstantial evidence must
rest.
Now, Dr. Taylor, by his own confession, is no authority in either
geology, biology, or palaeontology. He has neither collected,
observed, nor experimented in these fields. He does not know how
many facts have been discovered in them, or what bearing they have
on other facts in other fields. Therefore, he is entirely unable to
say whether Huxley is arguing from things "known or proved" or not.
Moreover, he does not, for similar reasons, know whether Huxley's
process has been "fatally vitiated" by the dependence of any
"material circumstance" on conjecture, or by the insufficiency of
the "known facts" to exclude every other hypothesis; for, first, he
does not know what is in geological, biological, or palaeontological
induction a "material circumstance"--nor does any man know except by
prolonged study and observation--and, second, he does not know
whether "the known or proved facts" are sufficient to exclude every
other hypothesis, because he neither knows what facts are known nor
what is the probative force of such as are known. We can, however,
make Dr. Taylor's position still clearer by a homely illustration. A
wild Indian will, owing to prolonged observation and great acuteness
of the senses, tell by a simple inspection of grass or leaf-covered
ground, on which a scholar will perceive nothing unusual whatever,
that a man has recently passed over it. He will tell whether he was
walking or running, whether he carried a burden, whether he was
young or old, and how long ago and what hour of the day he went by.
He reaches all his conclusions by circumstantial evidence of
precisely the same character as that used by the geologist, though
he knows nothing about the formal logic or the process of induction.
Now, what Dr. Taylor would have us believe is that he can come out
of his study and pass judgment on the Indian's reasoning without
being able to see one of the "known facts" on which the reasoning
rests, or appreciate in any degree which of them is material to the
conclusion and which is not, or even to conjecture whether, taken
together, they exclude the hypothesis that it was not a man but a
cow or a dog which passed over the ground, and not to-day but
yesterday that the marks were made.
Dr. Taylor further on makes a display of this inability to
appreciate the logical value of scientific facts by asking: "Where
is the evidence, scientific or other, that there was evolution? We
see these fossils (those of the horse). Huxley _says_ they are as
they are because the higher evolved itself out of the lower; we
_say_ they are as they are because God created them in series." To
recur to the former illustration, it is as if the Indian should show
Dr. Taylor the marks on which he relied in his induction, and the
doctor should calmly reply: "I see the marks; you _say_ they were
made by a man's foot in walking; I, who have never given any
attention to the subject, and have never been in the woods before,
_say_ they were made by the rain." The fact is that if there were
any weight whatever in this kind of talk--if no equality of
knowledge were necessary between two disputants--it would enable an
ignorant field-hand to sweep away in one sentence the whole science
of geology and palaeontology, and even astronomy, and to dispose of
every conclusion on any subject drawn from a skilled and experienced
balancing of probabilities, or nice mathematical calculation, by
simply saying that he was not satisfied with the proofs.
Dr. Taylor's reasons for believing that the appearance of fossil
horses with a diminishing number of toes is caused by the creation
at separate periods of a four-, a three-, a two-, and a one-toed
horse are, he says, "personal, philosophical, historical," and he
opposes them with the utmost apparent sincerity to Huxley's
assertion that "there can be no scientific evidence" of such
creation. The "personal reason" for believing in successive
creations of sets of horses with a varying number of toes can,
of course, only be the reason so often urged in ball-room
disputation--that "I _feel_ it must be so;" the "philosophic reason"
can only be the one with which those who have frequented the society
of metaphysicians are very familiar, namely, a deduction from some
eminent speculator's opinion about the nature of the Supreme Being,
the conclusion being apparently that if the Creator wished to
diminish the number of a horse's toes, it would not do for him to
let one drop into disuse and so gradually disappear, but he would
have to make a new horse, on a new design. What Dr. Taylor means by
the "historical reason" we can only conjecture from his saying that
it is of the same order as his historical reason for believing "that
the Bible is the Word of God." The historical reason for this, we
presume, is that there are various literary and traditional proofs
that the Old Testament was held to be the Word of God by the Jewish
nation at a very early period, and was by them transmitted as such
to the modern Christian world, and that many of the prophecies
contained in it have received partial or a complete fulfilment. But
how by a process of this kind, partly literary and partly
conjectural, and attended by great difficulties at every step, he
would reach a fact of _prehistoric times_ of so much gravity as
creation in series, we think it would puzzle Dr. Taylor to explain.
Indeed, the mere production in a controversy of this nature of these
vague fancies, half pious, half poetical, conjured up in most cases
as a help to mental peace, by a leading minister in the character of
a logician, is a very remarkable proof of the extent of those
defects in clerical education to which we recently called attention.