CHAPTER X.

OF THE INDUCTION OF CAUSES.

APHORISM LX.

_In the_ Induction of Causes _the principal Maxim is, that we must

be careful to possess, and to apply, with perfect clearness, the

Fundamental Idea on which the Induction depends._

APHORISM LXI.

_The Induction of Substance, of Force, of Polarity, go beyond mere

laws of phenomena, and may be considered as the Induction of

Causes._

APHORISM LXII.

_The Cause of certain phenomena being inferred, we are led to

inquire into the Cause of this Cause, which inquiry must be

conducted in the same manner as the previous one; and thus we have

the Induction of Ulterior Causes._

APHORISM LXIII.

_In contemplating the series of Causes which are themselves the

effects of other causes, we are necessarily led to assume a Supreme

Cause in the Order of Causation, as we assume a First Cause in Order

of Succession._

1. WE formerly[53\3] stated the objects of the researches of Science

to be Laws of Phenomena and Causes; and showed the propriety and the

necessity of not resting in the former object, but extending our

{248} inquiries to the latter also. Inductions, in which phenomena

are connected by relations of Space, Time, Number and Resemblance,

belong to the former class; and of the Methods applicable to such

Inductions we have treated already. In proceeding to Inductions

governed by any ulterior Ideas, we can no longer lay down any

Special Methods by which our procedure may be directed. A few

general remarks are all that we shall offer.

[Note 53\3: B. ii. c. vii.]

The principal Maxim in such cases of Induction is the obvious

one:--that we must be careful to possess and to apply, with perfect

clearness and precision, the Fundamental Idea on which the Induction

depends.

We may illustrate this in a few cases.

2. _Induction of Substance._--The Idea of Substance[54\3] involves

this axiom, that the weight of the whole compound must be equal to

the weights of the separate elements, whatever changes the

composition or separation of the elements may have occasioned. The

application of this Maxim we may term the _Method of the Balance_.

We have seen[55\3] elsewhere how the memorable revolution in

Chemistry, the overthrow of Phlogiston, and the establishment of the

Oxygen Theory, was produced by the application of this Method. We

have seen too[56\3] that the same Idea leads us to this Maxim;--that

_Imponderable Fluids_ are not to be admitted as _chemical_ elements

of bodies.

[Note 54\3: _Hist. Sc. Ideas_, Book vi. c. iii.]

[Note 55\3: _Ibid._ b. vi. c. iv.]

[Note 56\3: _Ibid._]

Whether those which have been termed _Imponderable Fluids_,--the

supposed fluids which produce the phenomena of Light, Heat,

Electricity, Galvanism, Magnetism,--really exist or no, is a

question, not merely of the _Laws_, but of the _Causes_ of

Phenomena. It is, as has already been shown, a question which we

cannot help discussing, but which is at present involved in great

obscurity. Nor does it appear at all likely that we shall obtain a

true view of the cause of Light, Heat, and Electricity, till we have

discovered precise and general laws connecting optical, thermotical,

and {249} electrical _phenomena_ with those chemical doctrines to

which the Idea of Substance is necessarily applied.

3. _Induction of Force._--The inference of _Mechanical Forces_ from

phenomena has been so abundantly practised, that it is perfectly

familiar among scientific inquirers. From the time of Newton, it has

been the most common aim of mathematicians; and a persuasion has

grown up among them, that mechanical forces,--attraction and

repulsion,--are the only modes of action of the particles of bodies

which we shall ultimately have to consider. I have attempted to show

that this mode of conception is inadequate to the purposes of sound

philosophy;--that the Particles of crystals, and the Elements of

chemical compounds, must be supposed to be combined in some other

way than by mere mechanical attraction and repulsion. Dr. Faraday

has gone further in shaking the usual conceptions of the force

exerted, in well-known cases. Among the most noted and conspicuous

instances of attraction and repulsion exerted at a distance, were

those which take place between electrized bodies. But the eminent

electrician just mentioned has endeavoured to establish, by

experiments of which it is very difficult to elude the weight, that

the action in these cases does not take place at a distance, but is

the result of a chain of intermediate particles connected at every

point by forces of another kind.

4. _Induction of Polarity._--The forces to which Dr. Faraday

ascribes the action in these cases are _Polar Forces_[57\3]. We have

already endeavoured to explain the Idea of Polar Forces; which

implies[58\3] that at every point forces exactly equal act in

opposite directions; and thus, in the greater part of their course,

neutralize and conceal each other; while at the extremities of the

line, being by some cause liberated, they are manifested, still

equal and opposite. And the criterion by which this polar character

of forces is recognized, is implied in the reasoning of Faraday, on

the question of one or two electricities, of which we {250} formerly

spoke[59\3]. The maxim is this:--that in the action of polar forces,

along with every manifestation of force or property, there exists a

corresponding and simultaneous manifestation of an equal and

opposite force or property.

[Note 57\3: _Researches_, 12th series.]

[Note 58\3: B. v. c. i.]

[Note 59\3: Book v. c. i.]

5. As it was the habit of the last age to reduce all action to

mechanical forces, the present race of physical speculators appears

inclined to reduce all forces to polar forces. Mosotti has

endeavoured to show that the positive and negative electricities

pervade all bodies, and that gravity is only an apparent excess of

one of the kinds over the other. As we have seen, Faraday has given

strong experimental grounds for believing that the supposed remote

actions of electrized bodies are really the effects of polar forces

among contiguous particles. If this doctrine were established with

regard to all electrical, magnetical, and chemical forces, we might

ask, whether, while all other forces are polar, gravity really

affords a single exception to the universal rule? Is not the

universe pervaded by an omnipresent antagonism, a fundamental

conjunction of contraries, everywhere opposite, nowhere independent?

We are, as yet, far from the position in which Inductive Science can

enable us to answer such inquiries.

6. _Induction of Ulterior Causes._--The first Induction of a Cause

does not close the business of scientific inquiry. Behind proximate

causes, there are ulterior causes, perhaps a succession of such.

Gravity is the cause of the motions of the planets; but what is the

cause of gravity? This is a question which has occupied men's minds

from the time of Newton to the present day. Earthquakes and

volcanoes are the causes of many geological phenomena; but what is

the cause of those subterraneous operations? This inquiry after

ulterior causes is an inevitable result from the intellectual

constitution of man. He discovers mechanical causes, but he cannot

rest in them. He must needs ask, whence it is that matter has its

universal power of attracting matter. He discovers polar forces: but

even {251} if these be universal, he still desires a further insight

into the cause of this polarity. He sees, in organic structures,

convincing marks of adaptation to an end: whence, he asks, is this

adaptation? He traces in the history of the earth a chain of causes

and effects operating through time: but what, he inquires, is the

power which holds the end of this chain?

Thus we are referred back from step to step in the order of

causation, in the same, manner as, in the palætiological sciences,

we were referred back in the order of time. We make discovery after

discovery in the various regions of science; each, it may be,

satisfactory, and in itself complete, but none final. Something

always remains undone. The last question answered, the answer

suggests still another question. The strain of music from the lyre

of Science flows on, rich and sweet, full and harmonious, but never

reaches a close: no cadence is heard with which the intellectual ear

can feel satisfied.

_Of the Supreme Cause._--In the utterance of Science, no cadence is

heard with which the human mind can feel satisfied. Yet we cannot

but go on listening for and expecting a satisfactory close. The

notion of a cadence appears to be essential to our relish of the

music. The idea of some closing strain seems to lurk among our own

thoughts, waiting to be articulated in the notes which flow from the

knowledge of external nature. The idea of something ultimate in our

philosophical researches, something in which the mind can acquiesce,

and which will leave us no further questions to ask, of _whence_,

and _why_, and _by what power_, seems as if it belongs to us:--as if

we could not have it withheld from us by any imperfection or

incompleteness in the actual performances of science. What is the

meaning of this conviction? What is the reality thus anticipated?

Whither does the developement of this Idea conduct us?

We have already seen that a difficulty of the same kind, which

arises in the contemplation of causes and effects considered as

forming an historical series, drives us to the assumption of a First

Cause, as an Axiom {252} to which our Idea of Causation in time

necessarily leads. And as we were thus guided to a First Cause, in

order of Succession, the same kind of necessity directs us to a

Supreme Cause in order of Causation.

On this most weighty subject it is difficult to speak fitly; and the

present is not the proper occasion, even for most of that which may

be said. But there are one or two remarks which flow from the

general train of the contemplations we have been engaged in, and

with which this Work must conclude.

We have seen how different are the kinds of cause to which we are

led by scientific researches. _Mechanical Forces_ are insufficient

without _Chemical Affinities_; Chemical Agencies fail us, and we are

compelled to have recourse to _Vital Powers_; Vital Powers cannot be

merely physical, and we must believe in something hyperphysical,

something of the nature of a _Soul_. Not only do biological

inquiries lead us to assume an animal soul, but they drive us much

further; they bring before us _Perception_, and _Will_ evoked by

Perception. Still more, these inquiries disclose to us _Ideas_ as

the necessary forms of Perception, in the actions of which we

ourselves are conscious. We are aware, we cannot help being aware,

of our Ideas and our Volitions as belonging to _us_, and thus we

pass from _things_ to _persons_; we have the idea of _Personality_

awakened. And the idea of Design and _Purpose_, of which we are

conscious in our own minds, we find reflected back to us, with a

distinctness which we cannot overlook, in all the arrangements which

constitute the frame of organized beings.

We cannot but reflect how widely diverse are the kinds of principles

thus set before us;--by what vast strides we mount from the lower to

the higher, as we proceed through that series of causes which the

range of the sciences thus brings under our notice. Yet we know how

narrow is the range of these sciences when compared with the whole

extent of human knowledge. We cannot doubt that on many other

subjects, besides those included in physical speculation, man has

made out solid and satisfactory trains of {253} connexion;--has

discovered clear and indisputable evidence of causation. It is

manifest, therefore, that, if we are to attempt to ascend to the

Supreme Cause--if we are to try to frame an idea of the Cause of all

these subordinate causes;--we must conceive it as more different

from any of them, than the most diverse are from each other;--more

elevated above the highest, than the highest is above the lowest.

But further;--though the Supreme Cause must thus be inconceivably

different from all subordinate causes, and immeasurably elevated

above them all, it must still include in itself all that is

essential to each of them, by virtue of that very circumstance that

it is the Cause of their Causality. Time and Space,--Infinite Time

and Infinite Space,--must be among its attributes; for we cannot but

conceive Infinite Time and Space as attributes of the Infinite Cause

of the universe. Force and Matter must depend upon it for their

efficacy; for we cannot conceive the activity of Force, or the

resistance of Matter, to be independent powers. But these are its

lower attributes. The Vital Powers, the Animal Soul, which are the

Causes of the actions of living things, are only the Effects of the

Supreme Cause of Life. And this Cause, even in the lowest forms of

organized bodies, and still more in those which stand higher in the

scale, involves a reference to Ends and Purposes, in short, to

manifest Final Causes. Since this is so, and since, even when we

contemplate ourselves in a view studiously narrowed, we still find

that we have Ideas, and Will and Personality, it would render our

philosophy utterly incoherent and inconsistent with itself, to

suppose that Personality, and Ideas, and Will, and Purpose, do not

belong to the Supreme Cause from which we derive all that we have

and all that we are.

But we may go a step further;--though, in our present field of

speculation, we confine ourselves to knowledge founded on the facts

which the external world presents to us, we cannot forget, in

speaking of such a theme as that to which we have thus been led,

that these are but a small, and the least significant {254} portion

of the facts which bear upon it. We cannot fail to recollect that

there are facts belonging to the world within us, which more readily

and strongly direct our thoughts to the Supreme Cause of all things.

We can plainly discern that we have Ideas elevated above the region

of mechanical causation, of animal existence, even of mere choice

and will, which still have a clear and definite significance, a

permanent and indestructible validity. We perceive as a fact, that

we have a Conscience, judging of Right and Wrong; that we have Ideas

of Moral Good and Evil, that we are compelled to conceive the

organization of the moral world, as well as of the vital frame, to

be directed to an end and governed by a purpose. And since the

Supreme Cause is the cause of these facts, the Origin of these

Ideas, we cannot refuse to recognize Him as not only the Maker, but

the Governor of the World; as not only a Creative, but a

Providential Power; as not only a Universal Father, but an Ultimate

Judge.

We have already passed beyond the boundary of those speculations

which we proposed to ourselves as the basis of our conclusions. Yet

we may be allowed to add one other reflection. If we find in

ourselves Ideas of Good and Evil, manifestly bestowed upon us to be

the guides of our conduct, which guides we yet find it impossible

consistently to obey;--if we find ourselves directed, even by our

natural light, to aim at a perfection of our moral nature from which

we are constantly deviating through weakness and perverseness; if,

when we thus lapse and err, we can find, in the region of human

philosophy, no power which can efface our aberrations, or reconcile

our actual with our ideal being, or give us any steady hope and

trust with regard to our actions, after we have thus discovered

their incongruity with their genuine standard;--if we discern that

this is our condition, how can we fail to see that it is in the

highest degree consistent with all the indications supplied by such

a philosophy as that of which we have been attempting to lay the

foundations, that the Supreme Cause, through whom man exists as

{255} a moral being of vast capacities and infinite Hopes, should

have Himself provided a teaching for our ignorance, a propitiation

for our sin, a support for our weakness, a purification and

sanctification of our nature?

And thus, in concluding our long survey of the grounds and structure

of science, and of the lessons which the study of it teaches us, we

find ourselves brought to a point of view in which we can cordially

sympathize, and more than sympathize, with all the loftiest

expressions of admiration and reverence and hope and trust, which

have been uttered by those who in former times have spoken of the

elevated thoughts to which the contemplation of the nature and

progress of human knowledge gives rise. We can not only hold with

Galen, and Harvey, and all the great physiologists, that the organs

of animals give evidence of a purpose;--not only assert with Cuvier

that this conviction of a purpose can alone enable us to understand

every part of every living thing;--not only say with Newton that

'every true step made in philosophy brings us nearer to the First

Cause, and is on that account highly to be valued;'--and that 'the

business of natural philosophy is to deduce causes from effects,

till we come to the very First Cause, which certainly is not

mechanical;'--but we can go much farther, and declare, still with

Newton, that 'this beautiful system could have its origin no other

way than by the purpose and command of an intelligent and powerful

Being, who governs all things, not as the soul of the world, but as

the Lord of the Universe; who is not only God, but Lord and

Governor.'

When we have advanced so far, there yet remains one step. We may

recollect the prayer of one, the master in this school of the

philosophy of science: 'This also we humbly and earnestly beg;--that

human things may not prejudice such as are divine;--neither that

from the unlocking of the gates of sense, and the kindling of a

greater natural light, anything may arise of incredulity or

intellectual night towards divine mysteries; but rather that by our

minds thoroughly {256} purged and cleansed from fancy and vanity,

and yet subject and perfectly given up to the divine oracles, there

may be given unto faith the things that are faith's.' When we are

thus prepared for a higher teaching, we may be ready to listen to a

greater than Bacon, when he says to those who have sought their God

in the material universe, 'Whom ye ignorantly worship, him declare I

unto you.' And when we recollect how utterly inadequate all human

language has been shown to be, to express the nature of that Supreme

Cause of the Natural, and Rational, and Moral, and Spiritual world,

to which our Philosophy points with trembling finger and shaded

eyes, we may receive, with the less wonder but with the more

reverence, the declaration which has been vouchsafed to us:

ΕΝ AΡΧΗ ΗΝ Ὁ ΛΟΓΟΣ, ΚΑI Ὁ ΛΟΓΟΣ ΗΝ ΠΡΟΣ ΤΟΝ ΘΕΟΝ, ΚΑI ΘΕΟΣ ΗΝ Ὁ

ΛΟΓΟΣ.

{{257}}

NOVUM ORGANON RENOVATUM.

BOOK IV.

OF THE LANGUAGE OF SCIENCE.

INTRODUCTION.

IT has been shown in the _History of the Sciences_, and has further

appeared in the course of the _History of Ideas_, that almost every

step in the progress of science is marked by the formation or

appropriation of a technical term. Common language has, in most

cases, a certain degree of looseness and ambiguity; as common

knowledge has usually something of vagueness and indistinctness. In

common cases too, knowledge usually does not occupy the intellect

alone, but more or less interests some affection, or puts in action

the fancy; and common language, accommodating itself to the office

of expressing such knowledge, contains, in every sentence, a tinge

of emotion or of imagination. But when our knowledge becomes

perfectly exact and purely intellectual, we require a language which

shall also be exact and intellectual;--which shall exclude alike

vagueness and fancy, imperfection and superfluity;--in which each

term shall convey a meaning steadily fixed and rigorously limited.

Such a language that of science becomes, through the use of

Technical Terms. And we must now endeavour to lay down some maxims

and suggestions, by attention to which Technical Terms may be better

fitted to answer their purpose. In order to do this, we shall in

{258} the first place take a rapid survey of the manner in which

Technical Terms have been employed from the earliest periods of

scientific history.

The progress of the use of technical scientific language offers to

our notice two different and successive periods; in the first of

which, technical terms were formed casually, as convenience in each

case prompted; while in the second period, technical language was

constructed intentionally, with set purpose, with a regard to its

connexion, and with a view of constructing a system. Though the

casual and the systematic formation of technical terms cannot be

separated by any precise date of time, (for at all periods some

terms in some sciences have been framed unsystematically,) we may,

as a general description, call the former the _Ancient_ and the

latter the _Modern_ Period. In illustrating the two following

Aphorisms, I will give examples of the course followed in each of

these periods.

APHORISM I.

_In the Ancient Period of Sciences, Technical Terms were formed in

three different ways:--by appropriating common words and fixing

their meaning;--by constructing terms containing a description;--by

constructing terms containing reference to a theory._

THE earliest sciences offer the earliest examples of technical

terms. These are Geometry, Arithmetic, and Astronomy; to which we

have soon after to add Harmonics, Mechanics, and Optics. In these

sciences, we may notice the above-mentioned three different modes in

which technical terms were formed.

I. The simplest and first mode of acquiring technical terms, is to

take words current in common usage, and by rigorously defining or

otherwise fixing their meaning, to fit them for the expression of

scientific truths. In this manner almost all the fundamental

technical terms of Geometry were formed. A _sphere_, a _cone_, a

_cylinder_, had among the Greeks, at first, {259} meanings less

precise than those which geometers gave to these words, and besides

the mere designation of form, implied some use or application. A

_sphere_ (σφαῖρα) was a hand-ball used in games; a _cone_ (κῶνος)

was a boy's spinning-top, or the crest of a helmet; a _cylinder_

(κύλινδρος) was a roller; a _cube_ (κύβος) was a die: till these

words were adopted by the geometers, and made to signify among them

pure modifications of space. So an _angle_ (γωνία) was only a

corner; a _point_ (σημεῖον) was a signal; a _line_ (γραμμὴ) was a

mark; a _straight_ line (εὐθεῖα) was marked by an adjective which at

first meant only _direct_. A _plane_ (ἐπίπεδον) is the neuter form

of an adjective, which by its derivation means _on the ground_, and

hence _flat_. In all these cases, the word adopted as a term of

science has its sense rigorously fixed; and where the common use of

the term is in any degree vague, its meaning may be modified at the

same time that it is thus limited. Thus a _rhombus_ (ῥόμβος) by its

derivation, might mean any figure which is _twisted_ out of a

regular form; but it is confined by geometers to that figure which

has four equal sides, its angles being oblique. In like manner, a

_trapezium_ (τραπέζιον) originally signifies a _table_, and thus

might denote any form; but as the tables of the Greeks had one side

shorter than the opposite one, such a figure was at first called a

_trapezium_. Afterwards the term was made to signify any figure with

four unequal sides; a name being more needful in geometry for this

kind of figure than for the original form.

This class of technical terms, namely, words adopted from common

language, but rendered precise and determinate for purposes of

science, may also be exemplified in other sciences. Thus, as was

observed in the early portion of the history of astronomy[1\4], a

_day_, a _month_, a _year_, described at first portions of time

marked by familiar changes, but afterwards portions determined by

rigorous mathematical definitions. The conception of the heavens as

a revolving sphere, is so obvious, {260} that we may consider the

terms which involve this conception as parts of common language; as

the _pole_ (πόλος); the _arctic circle_, which includes the stars

that never set[2\4]; the _horizon_ (ὁρίζων) a boundary, applied

technically to the circle bounding the visible earth and sky. The

_turnings of the sun_ (τροπαὶ ἠελίοιο), which are mentioned by

Hesiod, gave occasion to the term _tropics_, the circles at which

the sun in his annual motion turns back from his northward or

southward advance. The _zones_ of the earth, (the _torrid_,

_temperate_, and _frigid_;) the _gnomon_ of a dial; the _limb_ (or

border) of the moon, or of a circular instrument, are terms of the

same class. An _eclipse_ (ἔκλειψις) is originally a deficiency or

disappearance, and joined with the name of the luminary, an _eclipse

of the sun_ or _of the moon_, described the phenomenon; but when the

term became technical, it sufficed, without addition, to designate

the phenomenon.

[Note 1\4: _Hist. Ind. Sci._ b. iii. c. i.]

[Note 2\4: _Hist. Ast._ b. iii. c. i. sect. 8.]

In Mechanics, the Greeks gave a scientific precision to very few

words: we may mention _weights_ (βάρεα), the _arms of a lever_

(μήχεα), its _fulcrum_ (ὑπομόχλιον), and the verb _to balance_

(ἰσσοῤῥοπεῖν). Other terms which they used, as _momentum_ (ῥοπὴ) and

_force_ (δύναμις), did not acquire a distinct and definite meaning

till the time of Galileo, or later. We may observe that all abstract

terms, though in their scientific application expressing mere

conceptions, were probably at first derived from some word

describing external objects. Thus the Latin word for force, _vis_,

seems to be connected with a Greek word, ἲς, or ϝὶς, which often has

nearly the same meaning; but originally, as it would seem, signified

a sinew or muscle, the obvious seat of animal strength.

In later times, the limitation imposed upon a word by its

appropriation to scientific purposes, is often more marked than in

the cases above described. Thus the _variation_ is made to mean, in

astronomy, the second inequality of the moon's motion; in magnetism,

the _variation_ signifies the angular deviation of the {261}

compass-needle from the north; in pure mathematics, the _variation_

of a quantity is the formula which expresses the result of any small

change of the most general kind. In like manner, _parallax_

(παράλλαξις) denotes a _change_ in general, but is used by

astronomers to signify the change produced by the spectator's being

removed from the center of the earth, his theoretical place, to the

surface. _Alkali_ at first denoted the ashes of a particular plant,

but afterwards, all bodies having a certain class of chemical

properties; and, in like manner, _acid_, the class opposed to

alkali, was modified in signification by chemists, so as to refer no

longer to the taste.

Words thus borrowed from common language, and converted by

scientific writers into technical terms, have some advantages and

some disadvantages. They possess this great convenience, that they

are understood after a very short explanation, and retained in the

memory without effort. On the other hand, they lead to some

inconvenience; for since they have a meaning in common language, a

careless reader is prone to disregard the technical limitation of

this meaning, and to attempt to collect their import in scientific

books, in the same vague and conjectural manner in which he collects

the purpose of words in common cases. Hence the language of science,

when thus resembling common language, is liable to be employed with

an absence of that scientific precision which alone gives it value.

Popular writers and talkers, when they speak of _force_, _momentum_,

_action and reaction_, and the like, often afford examples of the

inaccuracy thus arising from the scientific appropriation of common

terms.

II. Another class of technical terms, which we find occurring as

soon as speculative science assumes a distinct shape, consists of

those which are intentionally constructed by speculators, and which

contain some description or indication distinctive of the conception

to which they are applied. Such are a _parallelogram_

(παραλληλόγραμμον), which denotes a plane figure bounded by two

pairs of parallel lines; a _parallelopiped_ {262}

(παραλληλοπίπεδον), which signifies a solid figure bounded by three

pairs of parallel planes. A _triangle_ (τρίγωνος, _trigon_) and a

_quadrangle_ (τετράγωνος, _tetragon_) were perhaps words invented

independently of the mathematicians: but such words extended to

other cases, _pentagon_, _decagon_, _heccædecagon_, _polygon_, are

inventions of scientific men. Such also are _tetrahedron_,

_hexahedron_, _dodecahedron_, _tesseracontaoctohedron_,

_polyhedron_, and the like. These words being constructed by

speculative writers, explain themselves, or at least require only

some conventional limitation, easily adopted. Thus _parallelogram_,

might mean a figure bounded by any number of sets of parallel lines,

but it is conventionally restricted to a figure of _four_ sides. So

a _great circle_ in a sphere means one which passes through the

center of the sphere; and a _small circle_ is any other. So in

trigonometry, we have the hypotenuse (ὑποτενοῦσα), or _subtending_

line, to designate the line subtending an angle, and especially a

right angle. In this branch of mathematics we have many invented

technical terms; as _complement_, _supplement_, _cosine_,

_cotangent_, a _spherical angle_, the _pole of a circle_, or of a

sphere. The word _sine_ itself appears to belong to the class of

terms already described as scientific appropriations of common

terms, although its origin is somewhat obscure.

Mathematicians were naturally led to construct these and many other

terms by the progress of their speculations. In like manner, when

astronomy took the form of a speculative science, words were

invented to denote distinctly the conceptions thus introduced. Thus

the sun's annual path among the stars, in which not only solar, but

also all lunar eclipses occur, was termed the _ecliptic_. The circle

which the sun describes in his diurnal motion, when the days and

nights are equal, the Greeks called the _equidiurnal_ (ἰσημερινὸς,)

the Latin astronomers the _equinoctial_, and the corresponding

circle on the earth was the _equator_. The ecliptic intersected the

equinoctial in the _equinoctial points_. The _solstices_ (in Greek,

τροπαὶ) were the times when the sun arrested his motion northwards

or {263} southwards; and the _solstitial points_ (τὰ τροπικὰ σημεῖα)

were the places, in the ecliptic where he then was. The name of

_meridians_ was given to circles passing through the poles of the

equator; the _solstitial colure_ (κόλουρος, curtailed), was one of

these circles, which passes through the solstitial points, and is

intercepted by the horizon.

We have borrowed from the Arabians various astronomical terms, as

_Zenith_, _Nadir_, _Azimuth_, _Almacantar_. And these words, which

among the Arabians probably belonged to the first class, of

appropriated scientific terms, are for us examples of the second

class, invented scientific terms; although they differ from most

that we have mentioned, in not containing an etymology corresponding

to their meaning in any language with which European cultivators of

science are generally familiar. Indeed, the distinction of our two

classes, though convenient, is in a great measure, casual. Thus most

of the words we formerly mentioned, as _parallax_, _horizon_,

_eclipse_, though appropriated technical terms among the Greeks, are

to us invented technical terms.

In the construction of such terms as we are now considering, those

languages have a great advantage which possess a power of forming

words by composition. This was eminently the case with the Greek

language; and hence most of the ancient terms of science in that

language, when their origin is once explained, are clearly

understood and easily retained. Of modern European languages, the

German possesses the greatest facility of composition; and hence

scientific authors in that language are able to invent terms which

it is impossible to imitate in the other languages of Europe. Thus

Weiss distinguishes his various systems of crystals as

_zwei-und-zwei-gliedrig_, _ein-und-zwei-gliedrig_,

_drey-und-drey-gliedrig,_ _&c._, (two-and-two-membered,

one-and-two-membered, &c.) And Hessel, also a writer on

crystallography, speaks of _doubly-one-membered edges_,

_four-and-three spaced rays_, and the like.

How far the composition of words, in such cases, may be practised in

the English language, and the general question, what are the best

rules and artifices {264} in such cases, I shall afterwards

consider. In the mean time, I may observe that this list of invented

technical terms might easily be much enlarged. Thus in harmonics we

have the various intervals, as a _Fourth_, a _Fifth_, an _Octave_,

(_Diatessaron_, _Diapente_, _Diapason_,) a _Comma_, which is the

difference of a _Major_ and _Minor Tone_; we have the various

_Moods_ or _Keys_, and the notes of various lengths, as _Minims_,

_Breves_, _Semibreves_, _Quavers_. In chemistry, _Gas_ was at first

a technical term invented by Van Helmont, though it has now been

almost adopted into common language. I omit many words which will

perhaps suggest themselves to the reader, because they belong rather

to the next class, which I now proceed to notice.

III. The third class of technical terms consists of such as are

constructed by men of science, and involve some theoretical idea in

the meaning which their derivation implies. They do not merely

describe, like the class last spoken of, but describe with reference

to some doctrine or hypothesis which is accepted as a portion of

science. Thus _latitude_ and _longitude_, according to their origin,

signify breadth and length; they are used, however, to denote

measures of the distance of a place on the earth's surface from the

equator, and from the first meridian, of which distances, one cannot

be called _length_ more properly than the other. But this

appropriation of these words may be explained by recollecting that

the earth, as known to the ancient geographers, was much further

extended from east to west than from north to south. The

_Precession_ of the equinoxes is a term which implies that the stars

are fixed, while the point which is the origin of the measure of

celestial longitude moves backward. The _Right Ascension_ of a star

is a measure of its position corresponding to terrestrial longitude;

this quantity is identical with the angular ascent of the

equinoctial point, when the star is in the horizon in a _right_

sphere; that is, a sphere which supposes the spectator to be at the

equator. The _Oblique Ascension_ (a term now little used), is

derived in like manner from an oblique sphere. The motion of a

planet is _direct_ or _retrograde_, _in_ {265} _consequentia_

(_signa_), or _in antecedentia_, in reference to a certain assumed

standard direction for celestial motions, namely, the direction

opposite to that of the sun's daily motion, and agreeing with his

annual motion among the stars; or with what is much more evident,

the moon's monthly motion. The _equation of time_ is the quantity

which must be added to or subtracted from the time marked by the

sun, in order to reduce it to a theoretical condition of equable

progress. In like manner the _equation of the center_ of the sun or

of the moon is the angle which must be added to, or subtracted from,

the actual advance of the luminary in the heavens, in order to make

its motion equable. Besides the equation of the center of the moon,

which represents the first and greatest of her deviations from

equable motion, there are many other _equations_, by the application

of which her motion is brought nearer and nearer to perfect

uniformity. The second of these equations is called the _evection_,

the third the _variation_, the fourth the _annual equation_, The

motion of the sun as affected by its inequalities is called his

_anomaly_, which term denotes inequality. In the History of

Astronomy, we find that the inequable motions of the sun, moon, and

planets were, in a great measure, reduced to rule and system by the

Greeks, by the aid of an hypothesis of circles, revolving, and

carrying in their motion other circles which also revolved. This

hypothesis introduced many technical terms, as _deferent_,

_epicycle_, _eccentric_. In like manner, the theories which have

more recently taken the place of the theory of epicycles have

introduced other technical terms, as the _elliptical orbit_, the

_radius vector_, and the _equable description of areas_ by this

radius, which phrases express the true laws of the planetary

motions.

There is no subject on which theoretical views have been so long and

so extensively prevalent as astronomy, and therefore no other

science in which there are so many technical terms of the kind we

are now considering. But in other subjects also, so far as theories

have been established, they have been accompanied by the

introduction or fixation of technical terms. Thus, as {266} we have

seen in the examination of the foundations of mechanics, the terms

_force_ and _inertia_ derive their precise meaning from a

recognition of the first law of motion; _accelerating force_ and

_composition of motion_ involve the second law; _moving force_,

_momentum_, _action_ and _reaction_, are expressions which imply the

third law. The term _vis viva_ was introduced to express a general

property of moving bodies; and other terms have been introduced for

like purposes, as _impetus_ by Smeaton, and _work done_, by other

engineers. In the recent writings of several French engineers, the

term _travail_ is much employed, to express the work done and the

force which does it: this term has been rendered by _labouring

force_. The proposition which was termed the _hydrostatic paradox_

had this name in reference to its violating a supposed law of the

action of forces. The verb to _gravitate_, and the abstract term

_gravitation_, sealed the establishment of Newton's theory of the

solar system.

In some of the sciences, opinions, either false, or disguised in

very fantastical imagery, have prevailed; and the terms which have

been introduced during the reign of such opinions, bear the impress

of the time. Thus in the days of alchemy, the substances with which

the operator dealt were personified; and a metal when exhibited pure

and free from all admixture was considered as a little king, and was

hence called a _regulus_, a term not yet quite obsolete. In like

manner, a substance from which nothing more of any value could be

extracted, was dead, and was called a _caput mortuum_. Quick silver,

that is, live silver (_argentum vivum_), was killed by certain

admixtures, and was _revived_ when restored to its pure state.

We find a great number of medical terms which bear the mark of

opinions formerly prevalent among physicians; and though these

opinions hardly form a part of the progress of science, and were not

presented in our History, we may notice some of these terms as

examples of the mode in which words involve in their derivation

obsolete opinions. Such words as _hysterics_, _hypochondriac_,

_melancholy_, _cholera_, _colic_, _quinsey_ {267} (_squinantia_,

συνάγχη, a suffocation), _megrim_, _migrane_ (_hemicranium_, the

middle of the skull), _rickets_, (_rachitis_, from ῥάχις, the

backbone), _palsy_, (_paralysis_, παράλυσις,) _apoplexy_ (ἀποπληξία,

a stroke), _emrods_, (αἱμοῤῥοΐδες, _hemorrhoids_, a flux of blood),

_imposthume_, (corrupted from _aposteme_, ἀπόστημα, an abscess),

_phthisis_ (φθίσις, consumption), _tympanum_ (τυμπανία, swelling),

_dropsy_ (_hydropsy_, ὕδρωψ,) _sciatica_, isciatica (ἰσκιαδικὴ,

from ἰσκίον, the hip), _catarrh_ (κατάῤῥους, a flowing down),

_diarrhœa_ (διαῤῥοία, a flowing through), _diabetes_ (διαβήτης, a

passing through), _dysentery_ (δυσεντερία, a disorder of the

entrails), _arthritic_ pains (from ἄρθρα, the joints), are names

derived from the supposed or real seat and circumstances of the

diseases. The word from which the first of the above names is

derived (ὑστέρα, the last place,) signifies the womb, according to

its order in a certain systematic enumeration of parts. The second

word, _hypochondriac_, means something affecting the viscera below

the cartilage of the breastbone, which cartilage is called χόνδρος;

_melancholy_ and _cholera_ derive their names from supposed

affections of χολὴ, the bile. _Colic_ is that which affects the

_colon_ (κῶλον), the largest member of the bowels. A disorder of the

eye is called _gutta serena_ (the 'drop serene' of Milton), in

contradistinction to _gutta turbida_, in which the impediment to

vision is perceptibly opake. Other terms also record the opinions of

the ancient anatomists, as _duodenum_, a certain portion of the

intestines, which they estimated as twelve inches long. We might add

other allusions, as the _tendon of Achilles_.

Astrology also supplied a number of words founded upon fanciful

opinions; but this study having been expelled from the list of

sciences, such words now survive, only so far as they have found a

place in common language. Thus men were termed _mercurial_,

_martial_, _jovial_, or _saturnine_, accordingly as their characters

were supposed to be determined by the influence of the planets,

Mercury, Mars, Jupiter, or Saturn. Other expressions, such as

_disastrous_, _ill-starred_, _exorbitant_, _lord of the ascendant_,

and hence _ascendancy_, _influence_, {268} a _sphere of action_, and

the like, may serve to show how extensively astrological opinions

have affected language, though the doctrine is no longer a

recognized science.

The preceding examples will make it manifest that opinions, even of

a recondite and complex kind, are often implied in the derivation of

words; and thus will show how scientific terms, framed by the

cultivators of science, may involve received hypotheses and

theories. When terms are thus constructed, they serve not only to

convey with ease, but to preserve steadily and to diffuse widely,

the opinions which they thus assume. Moreover, they enable the

speculator to employ these complex conceptions, the creations of

science, and the results of much labour and thought, as readily and

familiarly as if they were convictions borrowed at once from the

senses. They are thus powerful instruments in enabling philosophers

to ascend from one step of induction and generalization to another;

and hereby contribute powerfully to the advance of knowledge and

truth.

It should be noticed, before we proceed, that the names of natural

objects, when they come to be considered as the objects of a

science, are selected according to the processes already enumerated.

For the most part, the natural historian adopts the common names of

animals, plants, minerals, gems, and the like, and only endeavours

to secure their steady and consistent application. But many of these

names imply some peculiar, often fanciful, belief respecting the

object.

Various plants derive their names from their supposed virtues, as

_herniaria_, _rupture-wort_; or from legends, as _herba Sancti

Johannis_, _St. John's wort_. The same is the case with minerals:

thus the _topaz_ was asserted to come from an island so shrouded in

mists that navigators could only _conjecture_ (τοπάζειν) where it

was. In these latter cases, however, the legend is often not the

true origin of the name, but is suggested by it.

The privilege of constructing names where they are wanted, belongs

to natural historians no less than to {269} the cultivators of

physical science; yet in the ancient world, writers of the former

class appear rarely to have exercised this privilege, even when they

felt the imperfections of the current language. Thus Aristotle

repeatedly mentions classes of animals which have no name, as

co-ordinate with classes that have names; but he hardly ventures to

propose names which may supply these defects[3\4]. The vast

importance of nomenclature in natural history was not recognized

till the modern period.

[Note 3\4: In his _History of Animals_, (b. i. c. vi.), he says,

that the great classes of animals are Quadrupeds, Birds, Fishes,

Whales (_Cetaceans_), Oysters (_Testaceans_), animals like crabs

which have no general name (_Crustaceans_), soft animals (_Mollusks_

and _Insects_). He does, however, call the Crustaces by a name

(_Malacostraca_, soft-shelled) which has since been adopted by

Naturalists.]

We have, however, hitherto considered only the formation or

appropriation of single terms in science; except so far as several

terms may in some instances be connected by reference to a common

theory. But when the value of technical terms began to be fully

appreciated, philosophers proceeded to introduce them into their

sciences more copiously and in a more systematic manner. In this

way, the modern history of technical language has some features of a

different aspect from the ancient; and must give rise to a separate

Aphorism.

APHORISM II.

_In the Modern Period of Science, besides the three processes

anciently employed in the formation of technical terms, there have

been introduced Systematic Nomenclature, Systematic Terminology, and

the Systematic Modification of Terms to express theoretical

relations_[4\4].

[Note 4\4: On the subject of Terminology and Nomenclature, see also

Aphorisms LXXXVIII and XCVIII concerning Ideas, and b. viii. c. ii.

of the _History of Scientific Ideas_. In those places I have spoken

of the distinction of _Terminology_ and _Nomenclature_.]

WRITERS upon science have gone on up to modern times forming such

technical terms as they had occasion for, by the three processes

above {270} described;--namely, appropriating and limiting words in

common use;--constructing for themselves words descriptive of the

conception which they wished to convey;--or framing terms which by

their signification imply the adoption of a theory. Thus among the

terms introduced by the study of the connexion between magnetism and

electricity, the word _pole_ is an example of the first kind; the

name of the subject, _electro-magnetism_, of the second; and the

term _current_, involving an hypothesis of the motion of a fluid, is

an instance of the third class. In chemistry, the term _salt_ was

adopted from common language, and its meaning extended to denote any

compound of a certain kind; the term _neutral_ salt implied the

notion of a balanced opposition in the two elements of the compound;

and such words as _subacid_ and _superacid_, invented on purpose,

were introduced to indicate the cases in which this balance was not

attained. Again, when the phlogistic theory of chemistry was

established, the term _phlogiston_ was introduced to express the

theory, and from this such terms as _phlogisticated_ and

_dephlogisticated_ were derived, exclusively words of science. But

in such instances as have just been given, we approach towards a

systematic modification of terms, which is a peculiar process of

modern times. Of this, modern chemistry forms a prominent example,

which we shall soon consider, but we shall first notice the other

processes mentioned in the Aphorism.

I. In ancient times, no attempt was made to invent or select a

Nomenclature of the objects of Natural History which should be

precise and permanent. The omission of this step by the ancient

naturalists gave rise to enormous difficulty and loss of time when

the sciences resumed their activity. We have seen in the history of

the sciences of classification, and of botany in especial[5\4], that

the early cultivators of that study in modern times endeavoured to

identify all the plants described by Greek and Roman writers with

those which grow in the north of Europe; and were involved {271} in

endless confusion[6\4], by the multiplication of names of plants, at

the same time superfluous and ambiguous. The _Synonymies_ which

botanists (Bauhin and others) found it necessary to publish, were

the evidences of these inconveniences. In consequence of the

defectiveness of the ancient botanical nomenclature, we are even yet

uncertain with respect to the identification of some of the most

common trees mentioned by classical writers[7\4]. The ignorance of

botanists respecting the importance of nomenclature operated in

another manner to impede the progress of science. As a good

nomenclature presupposes a good system of classification, so, on the

other hand, a system of classification cannot become permanent

without a corresponding nomenclature. Cæsalpinus, in the sixteenth

century[8\4], published an excellent system of arrangement for

plants; but this, not being connected with any system of names, was

never extensively accepted, and soon fell into oblivion. The

business of framing a scientific botanical classification was in

this way delayed for about a century. In the same manner,

Willoughby's classification of fishes, though, as Cuvier says, far

better than any which preceded it, was never extensively adopted, in

consequence of having no nomenclature connected with it.

[Note 5\4: _Hist. Ind. Sc._ b. xvi. c. ii.]

[Note 6\4: _Hist. Ind. Sc._ b. xvi. c. iii. sect. 3.]

[Note 7\4: For instance, whether the _fagus_ of the Latins be the

beech or the chestnut.]

[Note 8\4: _Ib._ b. xvi. c. iii. sect. 2.]

II. Probably one main cause which so long retarded the work of

fixing at the same time the arrangement and the names of plants, was

the great number of minute and diversified particulars in the

structure of each plant which such a process implied. The stalks,

leaves, flowers, and fruits of vegetables, with their appendages,

may vary in so many ways, that common language is quite insufficient

to express clearly and precisely their resemblances and differences.

Hence botany required not only a fixed system of _names_ of plants,

but also an artificial system of phrases fitted to _describe_ their

parts: not only a _Nomenclature_, but also {272} a _Terminology_.

The Terminology was, in fact, an instrument indispensably requisite

in giving fixity to the Nomenclature. The recognition of the kinds

of plants must depend upon the exact comparison of their

resemblances and differences; and to become a part of permanent

science, this comparison must be recorded in words.

The formation of an exact descriptive language for botany was thus

the first step in that systematic construction of the technical

language of science, which is one of the main features in the

intellectual history of modern times. The ancient botanists, as De

Candolle[9\4] says, did not make any attempt to select terms of

which the sense was rigorously determined; and each of them employed

in his descriptions the words, metaphors, or periphrases which his

own genius suggested. In the History of Botany[10\4], I have noticed

some of the persons who contributed to this improvement. 'Clusius,'

it is there stated, 'first taught botanists to describe well. He

introduced exactitude, precision, neatness, elegance, method: he

says nothing superfluous; he omits nothing necessary.' This task was

further carried on by Jung and Ray[11\4]. In these authors we see

the importance which began to be attached to the exact definition of

descriptive terms; for example, Ray quotes Jung's definition of

_Caulis_, a stalk.

[Note 9\4: _Theor. Elem. de Bot._ p. 327.]

[Note 10\4: _Hist. Ind. Sc._ b. xvi. c. iii. sect. 3.]

[Note 11\4: _Hist. Ind. Sc._ b. xvi. c. iii. sect. 3 (about A.D.

1660).]

The improvement of descriptive language, and the formation of

schemes of classification of plants, went on gradually for some

time, and was much advanced by Tournefort. But at last Linnæus

embodied and followed out the convictions which had gradually been

accumulating in the breasts of botanists; and by remodelling

throughout both the terminology and the nomenclature of botany,

produced one of the greatest reforms which ever took place in any

science. He thus supplied a conspicuous example of such a reform,

and a most admirable model of a language, from which {273} other

sciences may gather great instruction. I shall not here give any

account of the terms and words introduced by Linnæus. They have been

exemplified in the _History of Science_[12\4]; and the principles

which they involve I shall consider separately hereafter. I will

only remind the reader that the great simplification in

_nomenclature_ which was the result of his labours, consisted in

designating each kind of plant by a _binary_ term consisting of the

name of the _genus_ combined with that of the _species_: an artifice

seemingly obvious, but more convenient in its results than could

possibly have been anticipated.

[Note 12\4: _Ib._ c. iv. sect. 1-3.]

Since Linnæus, the progress of Botanical Anatomy and of Descriptive

Botany have led to the rejection of several inexact expressions, and

to the adoption of several new terms, especially in describing the

structure of the fruit and the parts of cryptogamous plants. Hedwig,

Medikus, Necker, Desvaux, Mirbel, and especially Gærtner, Link, and

Richard, have proposed several useful innovations, in these as in

other parts of the subject; but the general mass of the words now

current consists still, and will probably continue to consist, of

the terms established by the Swedish Botanist[13\4].

[Note 13\4: De Candolle, _Th. Elem._ p. 307.]

When it was seen that botany derived so great advantages from a

systematic improvement of its language, it was natural that other

sciences, and especially classificatory sciences, should endeavour

to follow its example. This attempt was made in Mineralogy by

Werner, and afterwards further pursued by Mohs. Werner's innovations

in the descriptive language of Mineralogy were the result of great

acuteness, an intimate acquaintance with minerals, and a most

methodical spirit: and were in most respects great improvements upon

previous practices. Yet the introduction of them into Mineralogy was

far from regenerating that science, as Botany had been regenerated

by the Linnæan reform. It would seem that the perpetual {274}

scrupulous attention to most minute differences, (as of lustre,

colour, fracture,) the greater part of which are not really

important, fetters the mind, rather than disciplines it or arms it

for generalization. Cuvier has remarked[14\4] that Werner, after his

first _Essay on the Characters of Minerals_, wrote little; as if he

had been afraid of using the system which he had created, and

desirous of escaping from the chains which he had imposed upon

others. And he justly adds, that Werner dwelt least, in his

descriptions, upon that which is really the most important feature

of all, the crystalline structure. This, which is truly a definite

character, like those of Botany, does, when it can be clearly

discerned, determine the place of the mineral in a system. This,

therefore, is the character which, of all others, ought to be most

carefully expressed by an appropriate language. This task, hardly

begun by Werner, has since been fully executed by others, especially

by Romé de l'Isle, Haüy, and Mohs. All the forms of crystals can be

described in the most precise manner by the aid of the labours of

these writers and their successors. But there is one circumstance

well worthy our notice in these descriptions. It is found that the

language in which they can best be conveyed is not that of words,

but of _symbols_. The relations of space which are involved in the

forms of crystalline bodies, though perfectly definite, are so

complex and numerous, that they cannot be expressed, except in the

language of mathematics: and thus we have an extensive and recondite

branch of mathematical science, which is, in fact, only a part of

the Terminology of the mineralogist.

[Note 14\4: _Éloges_, ii. 134.]

The Terminology of Mineralogy being thus reformed, an attempt was

made to improve its Nomenclature also, by following the example of

Botany. Professor Mohs was the proposer of this innovation. The

names framed by him were, however, not composed of two but of three

elements, designating respectively the Species, the Genus, and the

Order[15\4]: thus he has such species as {275} _Rhombohedral Lime

Haloide_, _Octahedral Fluor Haloide_, _Prismatic Hal Baryte_. These

names have not been generally adopted; nor is it likely that any

names constructed on such a scheme will find acceptance among

mineralogists, till the higher divisions of the system are found to

have some definite character. We see no real mineralogical

significance in Mohs's Genera and Orders, and hence we do not expect

them to retain a permanent place in the science.

[Note 15\4: _Hist. Ind. Sc._ b. xv. c. ix.]

The only systematic names which have hitherto been generally

admitted in Mineralogy, are those expressing the chemical

constitution of the substance; and these belong to a system of

technical terms different from any we have yet spoken of, namely to

terms formed by systematic modification.

III. The language of Chemistry was already, as we have seen, tending

to assume a systematic character, even under the reign of the

phlogiston theory. But when oxygen succeeded to the throne, it very

fortunately happened that its supporters had the courage and the

foresight to undertake a completely new and systematic recoinage of

the terms belonging to the science. The new nomenclature was

constructed upon a principle hitherto hardly applied in science, but

eminently commodious and fertile; namely, the principle of

indicating a modification of relations of elements, by a change in

the termination of the word. Thus the new chemical school spoke of

sulph_uric_ and sulph_urous_ acids; of sulph_ates_ and sulph_ites_

of bases; and of sulph_urets_ of metals; and in like manner, of

phos_phoric_ and phos_phorous_ acids, of phos_phates_, phos_phites_,

phos_phurets_. In this manner a nomenclature was produced, in which

the very name of a substance indicated at once its constitution and

place in the system.

The introduction of this chemical language can never cease to be

considered one of the most important steps ever made in the

improvement of technical terms; and as a signal instance of the

advantages which may result from artifices apparently trivial, if

employed in a manner conformable to the laws of phenomena, and

systematically pursued. It was, however, proved that {276} this

language, with all its merits, had some defects. The relations of

elements in composition were discovered to be more numerous than the

modes of expression which the terminations supplied. Besides the

sulphurous and sulphuric acids, it appeared there were others; these

were called the _hyposulphurous_ and _hyposulphuric_: but these

names, though convenient, no longer implied, by their form, any

definite relation. The compounds of Nitrogen and Oxygen are, in

order, the _Protoxide_, the _Deutoxide_ or _Binoxide_; _Hyponitrous_

Acid, _Nitrous_ Acid, and _Nitric_ Acid. The nomenclature here

ceases to be systematic. We have three oxides of Iron, of which we

may call the first the _Protoxide_, but we cannot call the others

the _Deutoxide_ and _Trioxide_, for by doing so we should convey a

perfectly erroneous notion of the proportions of the elements. They

are called the _Protoxide_, the _Black_ Oxide, and the _Peroxide_.

We are here thrown back upon terms quite unconnected with the

system.

Other defects in the nomenclature arose from errours in the theory;

as for example the names of the muriatic, oxymuriatic, and

hyperoxymuriatic acids; which, after the establishment of the new

theory of chlorine, were changed to _hydrochloric_ acid, _chlorine_,

and _chloric_ acid.

Thus the chemical system of nomenclature, founded upon the oxygen

theory, while it shows how much may be effected by a good and

consistent scheme of terms, framed according to the real relations

of objects, proves also that such a scheme can hardly be permanent

in its original form, but will almost inevitably become imperfect

and anomalous, in consequence of the accumulation of new facts, and

the introduction of new generalizations. Still, we may venture to

say that such a scheme does not, on this account, become worthless;

for it not only answers its purpose in the stage of scientific

progress to which it belongs:--so far as it is not erroneous, or

merely conventional, but really systematic and significant of truth,

its terms can be translated at once into the language of any higher

generalization which is afterwards arrived at. If terms express

{277} relations really ascertained to be true, they can never lose

their value by any change of the received theory. They are like

coins of pure metal, which, even when carried into a country which

does not recognize the sovereign whose impress they bear, are still

gladly received, and may, by the addition of an explanatory mark,

continue part of the common currency of the country.

These two great instances of the reform of scientific language, in

Botany and in Chemistry, are much the most important and instructive

events of this kind which the history of science offers. It is not

necessary to pursue our historical survey further. Our remaining

Aphorisms respecting the Language of Science will be collected and

illustrated indiscriminately, from the precepts and the examples of

preceding philosophers of all periods[16\4].

[Note 16\4: See at the end of these Aphorisms, further illustrations

of them from the recent history of Comparative Anatomy and

Chemistry.]

We may, however, remark that Aphorisms III., IV., V., VI., VII.,

respect peculiarly the Formation of Technical Terms by the

Appropriation of Common Words, while the remaining ones apply to the

Formation of New Terms.

It does not appear possible to lay down a system of rules which may

determine and regulate the construction of all technical terms, on

all the occasions on which the progress of science makes them

necessary or convenient. But if we can collect a few maxims such as

have already offered themselves to the minds of philosophers, or

such as may be justified by the instances by which we shall

illustrate them, these maxims may avail to guide us in doubtful

cases, and to prevent our aiming at advantages which are

unattainable, or being disturbed by seeming imperfections which are

really no evils. I shall therefore state such maxims of this kind as

seem most sound and useful. {278}

APHORISM III.

_In framing scientific terms, the appropriation of old words is

preferable to the invention of new ones._

THIS maxim is stated by Bacon in his usual striking manner. After

mentioning _Metaphysic_, as one of the divisions of Natural

Philosophy, he adds[17\4]: 'Wherein I desire it may be conceived

that I use the word _metaphysic_ in a different sense from that that

is received: and in like manner I doubt not but it will easily

appear to men of judgment that in this and other particulars,

wheresoever my conception and notion may differ from the ancient,

yet I am studious to keep the ancient terms. For, hoping well to

deliver myself from mistaking by the order and perspicuous

expressing of that I do propound; I am otherwise zealous and

affectionate to recede as little from antiquity, either in terms or

opinions, as may stand with truth, and the proficience of knowledge,

. . . To me, that do desire, as much as lieth in my pen, to ground a

sociable intercourse between antiquity and proficience, it seemeth

best to keep a way with antiquity _usque ad aras_; and therefore to

retain the ancient terms, though I sometimes alter the uses and

definitions; according to the moderate proceeding in civil

governments, when, although there be some alteration, yet that

holdeth which Tacitus wisely noteth, _eadem magistratuum vocabula_.'

[Note 17\4: _De Augm._ lib. iii. c. iv.]

We have had before us a sufficient number of examples of scientific

terms thus framed; for they formed the first of three classes which

we described in the First Aphorism. And we may again remark, that

science, when she thus adopts terms which are in common use, always

limits and fixes their meaning in a technical manner. We may also

repeat here the warning already given respecting terms of this kind,

that they are peculiarly liable to mislead readers who {279} do not

take care to understand them in their technical instead of their

common signification. _Force_, _momentum_, _inertia_, _impetus_,

_vis viva_, are terms which are very useful, if we rigorously bear

in mind the import which belongs to each of them in the best

treatises on Mechanics; but if the reader content himself with

conjecturing their meaning from the context, his knowledge will be

confused and worthless.

In the application of this Third Aphorism, other rules are to be

attended to, which I add.

APHORISM IV.

_When common words are appropriated as technical terms, their

meaning and relations in common use should be retained as far as can

conveniently be done._

I WILL state an example in which this rule seems to be applicable.

Mr Davies Gilbert[18\4] has recently proposed the term _efficiency_

to designate the work which a machine, according to the force

exerted upon it, is capable of doing; the work being measured by the

weight raised, and the space through which it is raised, jointly.

The usual term employed among engineers for the work which a machine

actually does, measured in the way just stated, is _duty_. But as

there appears to be a little incongruity in calling that work

_efficiency_ which the machine _ought_ to do, when we call that work

_duty_ which it really does, I have proposed to term these two

quantities _theoretical efficiency_ and _practical efficiency_, or

_theoretical duty_ and _practical duty_[19\4].

[Note 18\4: _Phil. Trans._ 1827, p. 25.]

[Note 19\4: The term _travail_ is used by French engineers, to

express _efficiency_ or _theoretical duty_. This term has been

rendered in English by _labouring force_.]

Since common words are often vague in their meaning, I add as a

necessary accompaniment to the Third Aphorism the following:-- {280}

APHORISM V.

_When common words are appropriated as technical terms, their

meaning may be modified, and must be rigorously fixed._

THIS is stated by Bacon in the above extract: 'to retain the ancient

terms, though I sometimes _alter the uses and definitions_.' The

scientific use of the term is in all cases much more precise than

the common use. The loose notions of _velocity_ and _force_ for

instance, which are sufficient for the usual purposes of language,

require to be fixed by exact measures when these are made terms in

the science of Mechanics.

This scientific fixation of the meaning of words is to be looked

upon as a matter of convention, although it is in reality often an

inevitable result of the progress of science. _Momentum_ is

conventionally defined to be the product of the numbers expressing

the weight and the velocity; but then, it could be of no use in

expressing the laws of motion if it were defined otherwise.

Hence it is no valid objection to a scientific term that the word in

common language does not mean exactly the same as in its common use.

It is no sufficient reason against the use of the term _acid_ for a

class of bodies, that all the substances belonging to this class are

not sour. We have seen that a _trapezium_ is used in geometry for

any four-sided figure, though originally it meant a figure with two

opposite sides parallel and the two others equal. A certain stratum

which lies below the chalk is termed by English geologists _the

green sand_. It has sometimes been objected to this denomination

that the stratum has very frequently no tinge of green, and that it

is often composed of lime with little or no sand. Yet the term is a

good technical term in spite of these apparent improprieties; so

long as it is carefully applied to that stratum which is

geologically equivalent to the greenish sandy bed to which the

appellation was originally applied.

When it appeared that _geometry_ would have to be employed as much

at least about the heavens as the earth, Plato exclaimed against the

folly of calling the {281} science by such a name; since the word

signifies 'earth-measuring;' yet the word _geometry_ has retained

its place and answered its purpose perfectly well up to the present

day.

But though the meaning of the term may be modified or extended, it

must be rigorously fixed when it is appropriated to science. This

process is most abundantly exemplified by the terminology of Natural

History, and especially of Botany, in which each term has a most

precise meaning assigned to it. Thus Linnæus established exact

distinctions between _fasciculus_, _capitulum_, _racemus_,

_thyrsus_, _paniculus_, _spica_, _amentum_, _corymbus_, _umbella_,

_cyma_, _verticillus_; or, in the language of English Botanists, _a

tuft_, _a head_, _a cluster_, _a bunch_, _a panicle_, _a spike_, _a

catkin_, _a corymb_, _an umbel_, _a cyme_, _a whorl_. And it has

since been laid down as a rule[20\4], that each organ ought to have

a separate and appropriate name; so that the term _leaf_, for

instance, shall never be applied to _a leaflet_, _a bractea_, or _a

sepal_ of the calyx.

[Note 20\4: De Candolle, _Theor. El._ 328.]

Botanists have not been content with fixing the meaning of their

terms by verbal definition, but have also illustrated them by

figures, which address the eye. Of these, as excellent modern

examples, may be mentioned those which occur in the works of

Mirbel[21\4], and Lindley[22\4].

[Note 21\4: _Élémens de Botanique_.]

[Note 22\4: _Elements of Botany_.]

APHORISM VI.

_When common words are appropriated as technical terms, this must be

done so that they are not ambiguous in their application._

AN example will explain this maxim. The conditions of a body, as a

solid, a liquid, and an air, have been distinguished as different

_forms_ of the body. But the word _form_, as applied to bodies, has

other meanings; so that if we were to inquire in _what form_ water

exists in a snow-cloud, it might be doubted whether the forms of

crystallization were meant, or {282} the different forms of ice,

water, and vapour. Hence I have proposed[23\4] to reject the term

_form_ in such cases, and to speak of the different _consistence_ of

a body in these conditions. The term _consistence_ is usually

applied to conditions between solid and fluid; and may without

effort be extended to those limiting conditions. And though it may

appear more harsh to extend the term _consistence_ to the state of

air, it may be justified by what has been said in speaking of

Aphorism V.

[Note 23\4: _Hist. Ind. Sc._ b. x. c. ii. sect. 2.]

I may notice another example of the necessity of avoiding ambiguous

words. A philosopher who makes method his study, would naturally be

termed a _methodist_; but unluckily this word is already

appropriated to a religious sect: and hence we could hardly venture

to speak of Cæsalpinus, Ray, Morison, Rivinus, Tournefort, Linnæus,

and their successors, as _botanical methodists_. Again, by this

maxim, we are almost debarred from using the term _physician_ for a

cultivator of the science of physics, because it already signifies a

practiser of physic. We might, perhaps, still use _physician_ as the

equivalent of the French _physicien_, in virtue of Aphorism V.; but

probably it would be better to form a new word. Thus we may say,

that while the Naturalist employs principally the ideas of

resemblance and life, the _Physicist_ proceeds upon the ideas of

force, matter, and the properties of matter.

Whatever may be thought of this proposal, the maxim which it implies

is frequently useful. It is this.

APHORISM VII.

_It is better to form new words as technical terms, than to employ

old ones in which the last three Aphorisms cannot be complied with._

THE principal inconvenience attending the employment of new words

constructed expressly for the use of science, is the difficulty of

effectually introducing them. Readers will not readily take the

trouble to learn the meaning of a word, in which the memory is {283}

not assisted by some obvious suggestion connected with the common

use of language. When this difficulty is overcome, the new word is

better than one merely appropriated; since it is more secure from

vagueness and confusion. And in cases where the inconveniences

belonging to a scientific use of common words become great and

inevitable, a new word must be framed and introduced.

The Maxims which belong to the construction of such words will be

stated hereafter; but I may notice an instance or two tending to

show the necessity of the Maxim now before us.

The word _Force_ has been appropriated in the science of Mechanics

in two senses: as indicating the cause of motion; and again, as

expressing certain measures of the effects of this cause, in the

phrases _accelerating force_ and _moving force_. Hence we might have

occasion to speak of the accelerating or moving force _of_ a certain

_force_; for instance, if we were to say that the force which

governs the motions of the planets resides in the sun; and that the

accelerating force _of_ this _force_ varies only with the distance,

but its moving force varies as the product of the mass of the sun

and the planet. This is a harsh and incongruous mode of expression;

and might have been avoided, if, instead of _accelerating force_ and

_moving force_, single abstract terms had been introduced by Newton:

if, for instance, he had said that the velocity generated in a

second measures the _accelerativity_ of the force which produces it,

and the momentum produced in a second measures the _motivity_ of the

force.

The science which treats of heat has hitherto had no special

designation: treatises upon it have generally been termed treatises

_On Heat_. But this practice of employing the same term to denote

the property and the science which treats of it, is awkward, and

often ambiguous. And it is further attended with this inconvenience,

that we have no adjective derived from the name of the science, as

we have in other cases, when we speak of _acoustical_ experiments

and _optical_ theories. This inconvenience has led various persons

to suggest names for the Science of Heat. M. Comte {284} terms it

_Thermology_. In the _History of the Sciences_, I have named it

_Thermotics_, which appears to me to agree better with the analogy

of the names of other corresponding sciences, _Acoustics_ and

_Optics_.

_Electricity_ is in the same condition as Heat; having only one word

to express the property and the science. M. Le Comte proposes

_Electrology_: for the same reason as before, I should conceive

_Electrics_ more agreeable to analogy. The coincidence of the word

with the plural of Electric would not give rise to ambiguity; for

_Electrics_, taken as the name of a science, would be singular, like

_Optics_ and _Mechanics_. But a term offers itself to express

_common_ or _machine Electrics_, which appears worthy of admission,

though involving a theoretical view. The received doctrine of the

difference between Voltaic and Common Electricity is, that in the

former case the fluid must be considered as in motion, in the latter

as at rest. The science which treats of the former class of subjects

is commonly termed _Electrodynamics_, which obviously suggests the

name _Electrostatics_ for the latter.

The subject of the Tides is, in like manner, destitute of any name

which designates the science concerned about it. I have ventured to

employ the term _Tidology_, having been much engaged in tidological

researches.

Many persons possess a peculiarity of vision, which disables them

from distinguishing certain colours. On examining many such cases,

we find that in all such persons the peculiarities are the same; all

of them confounding scarlet with green, and pink with blue. Hence

they form a class, which, for the convenience of physiologists and

others, ought to have a fixed designation. Instead of calling them,

as has usually been done, 'persons having a peculiarity of vision,'

we might take a Greek term implying this meaning, and term them

_Idiopts_.

But my business at present is not to speak of the selection of new

terms when they are introduced, but to illustrate the maxim that the

necessity for their introduction often arises. The construction of

new terms will be treated of subsequently. {285}

APHORISM VIII.

_Terms must be constructed and appropriated so as to be fitted to

enunciate simply and clearly true general propositions._

THIS Aphorism may be considered as the fundamental principle and

supreme rule of all scientific terminology. It is asserted by

Cuvier, speaking of a particular case. Thus he says[24\4] of Gmelin,

that by placing the lamantin in the genus of morses, and the siren

in the genus of eels, he had rendered every general proposition

respecting the organization of those genera impossible.

[Note 24\4: _Règne Animal_, Introd. viii.]

The maxim is true of words appropriated as well as invented, and

applies equally to the mathematical, chemical, and classificatory

sciences. With regard to most of these, and especially the two

former classes, it has been abundantly exemplified already, in what

has previously been said, and in the _History of the Sciences_. For

we have there had to notice many technical terms, with the occasions

of their introduction; and all these occasions have involved the

intention of expressing in a convenient manner some truth or

supposed truth. The terms of Astronomy were adopted for the purpose

of stating and reasoning upon the relations of the celestial

motions, according to the doctrine of the sphere, and the other laws

which were discovered by astronomers. The few technical terms which

belong to Mechanics, _force_, _velocity_, _momentum_, _inertia_,

&c., were employed from the first with a view to the expression of

the laws of motion and of rest; and were, in the end, limited so as

truly and simply to express those laws when they were fully

ascertained. In Chemistry, the term _phlogiston_ was useful, as has

been shown in the _History_, in classing together processes which

really are of the same nature; and the nomenclature of the _oxygen_

theory was still preferable, because it enabled the chemist to

express a still greater number of general truths. {286}

To the connexion here asserted, of theory and nomenclature, we have

the testimony of the author of the oxygen theory. In the Preface to

his _Chemistry_, Lavoisier says:--'Thus while I thought myself

employed only in forming a Nomenclature, and while I proposed to

myself nothing more than to improve the chemical language, my work

transformed itself by degrees, without my being able to prevent it,

into a Treatise on the Elements of Chemistry.' And he then proceeds

to show how this happened.

It is, however, mainly through the progress of Natural History in

modern times, that philosophers have been led to see the importance

and necessity of new terms in expressing new truths. Thus Harvey, in

the Preface to his work on Generation, says:--'Be not offended if in

setting out the History of the Egg I make use of a new method, and

sometimes of unusual terms. For as they which find out a new

plantation and new shores call them by names of their own coining,

which posterity afterwards accepts and receives, so those that find

out new secrets have good title to their compellation. And here,

methinks, I hear Galen advising: If we consent in the things,

contend not about the words.'

The Nomenclature which answers the purposes of Natural History is a

Systematic Nomenclature, and will be further considered under the

next Aphorism. But we may remark, that the Aphorism now before us

governs the use of words, not in science only, but in common

language also. Are we to apply the name _fish_ to animals of the

whale kind? The answer is determined by our present rule: we are to

do so, or not, accordingly as we can best express true propositions.

If we are speaking of the internal structure and physiology of the

animal, we must not call them _fish_; for in these respects they

deviate widely from fishes: they have warm blood, and produce and

suckle their young as land quadrupeds do. But this would not prevent

our speaking of the _whale-fishery_, and calling such animals _fish_

on all occasions connected with this employment; for the relations

thus arising depend upon the animal's living in the water, and being

caught in a {287} manner similar to other fishes. A plea that human

laws which mention fish do not apply to whales, would be rejected at

once by an intelligent judge.

[A bituminiferous deposit which occurs amongst the coal measures in

the neighbourhood of Edinburgh was used as coal, and called 'Boghead

Cannel Coal.' But a lawsuit arose upon the question whether this,

which geologically was not _the coal_, should be regarded in law as

_coal_. The opinions of chemists and geologists, as well as of

lawyers, were discrepant, and a direct decision of the case was

evaded.[25\4]]

[Note 25\4: Miller's _Chemistry_, iii. 98.]

APHORISM IX.

_In the Classificatory Sciences, a Systematic Nomenclature is

necessary; and the System and the Nomenclature are each essential to

the utility of the other._

THE inconveniences arising from the want of a good Nomenclature were

long felt in Botany, and are still felt in Mineralogy. The attempts

to remedy them by _Synonymies_ are very ineffective, for such

comparisons of synonyms do not supply a systematic nomenclature; and

such a one alone can enable us to state general truths respecting

the objects of which the classificatory sciences treat. The _System_

and the _Names_ ought to be introduced together; for the former is a

collection of asserted analogies and resemblances, for which the

latter provide simple and permanent expressions. Hence it has

repeatedly occurred in the progress of Natural History, that good

Systems did not take root, or produce any lasting effect among

naturalists, because they were not accompanied by a corresponding

Nomenclature. In this way, as we have already noticed, the excellent

botanical System of Cæsalpinus was without immediate effect upon the

science. The work of Willoughby, as Cuvier says[26\4], forms an

epoch, and {288} a happy epoch in Ichthyology; yet because Willoughby

had no Nomenclature of his own, and no fixed names for his genera,

his immediate influence was not great. Again, in speaking of

Schlotheim's work containing representations of fossil vegetables,

M. Adolphe Brongniart observes[27\4] that the figures and

descriptions are so good, that if the author had established a

nomenclature for the objects he describes, his work would have

become the basis of all succeeding labours on the subject.

[Note 26\4: _Hist. des Poissons_, Pref.]

[Note 27\4: _Prodrom. Veg. Foss._ p. 3.]

As additional examples of cases in which the improvement of

classification, in recent times, has led philosophers to propose new

names, I may mention the term _Pœcilite_, proposed by Mr. Conybeare

to designate the group of strata which lies below the oolites and

lias, including the new red or variegated sandstone, with the keuper

above, and the magnesian limestone below it. Again, the transition

districts of our island have recently been reduced to system by

Professor Sedgwick and Mr. Murchison; and this step has been marked

by the terms _Cambrian_ system, and _Silurian_ system, applied to

the two great groups of formations which they have respectively

examined, and by several other names of the subordinate members of

these formations.

Thus System and Nomenclature are each essential to the other.

Without Nomenclature, the system is not permanently incorporated

into the general body of knowledge, and made an instrument of future

progress. Without System, the names cannot express general truths,

and contain no reason why they should be employed in preference to

any other names.

This has been generally acknowledged by the most philosophical

naturalists of modern times. Thus Linnæus begins that part of his

Botanical Philosophy in which names are treated of, by stating that

the foundation of botany is twofold, _Disposition_ and

_Denomination_; and he adds this Latin line,

Nomina si nescis perit et cognitio rerum. {289}

And Cuvier, in the Preface to his _Animal

Kingdom_, explains, in a very striking manner, how the attempt to

connect zoology with anatomy led him, at the same time, to reform

the classifications, and to correct the nomenclature of preceding

zoologists.