صور الصفحة
PDF
النشر الإلكتروني

CHAPTER XLIII.

The

present subject

comes at

the end of

THE

THE CLASSIFICATION OF THE SCIENCES.

HE appropriate place for a treatise on the classification and the mutual relation of the sciences is not at naturally the beginning, but at the end of a work like the present. A classification of the sciences is not and cannot be a the work. programme of work to be done, but only a résumé of work that has been done; in other words, it is impossible to classify the sciences until the sciences exist. It would have been impossible for Aristotle, or Bacon, or any other man, to lay down a chart of the course which scientific research and scientific thought would take when as yet science had scarcely begun its work. Such intellectual power as would have been needed in order to do so does not belong to man. To understand history is one of the highest attainments of man's intellect, but it does not belong to unassisted man to utter prophecy.

Any such

tion must

fect.

.

In this chapter it will be impossible for me to avoid repeating part of what has been said in the chapter on Organic Subordination.1

It is to be observed at the outset that a paper classificlassifica- cation of the sciences, like the paper classifications of be imper- zoology and botany, can be at the best only approximately correct. The divisions in both are in a great degree arbitrary, and the tabular form does not represent the real order of things with perfect accuracy. I think, however, that a much more complete and regular classification of the sciences is practicable than we could have expected.

1 Chapter XIII.

science.

When we seek for points of connexion between the sciences to serve as a basis for their classification, we come on this rather embarrassing fact, that there are subjects Subjects which belong to more than one science. I do not mean to more belonging cases like those which occur in organic classification, where than one it is sometimes doubtful on which side of a boundary-line we ought to place some particular form. I mean cases where there is no doubt whatever that they belong equally to two sciences. Whether, for instance, does spectrum Spectrum analysis belong to optics or to chemistry? Whether do analysis: polarizing the polarizing properties of crystals belong to optics or to crystals: crystallography? Whether do the facts of electro-chemical chemistry. decomposition and the theory of the voltaic battery belong

to chemistry or to electricity? The only possible answer is, that they belong equally to both.

electro

another,

This, then, is one kind of connexion between the sciences -namely, that one and the same subject may belong to more than one science. Another kind is when one science One gives suggestions to another-such as, to mention the best science giving instance that occurs to me, the instructive and valuable sugges idea of the physiological division of labour which the tions to science of human society has furnished to biology. A third kind of connexion is when one science furnishes materials or furnishto another, as in the case of biology furnishing to che- ing matemistry a variety of new substances, which constitute the another, subject of the branch of the latter science called organic chemistry. A fourth way is when one science becomes, in or supplythe literal sense, instrumental to another: I mean, when ing instru one science supplies another with instruments.

rials to

ments to

Thus, another.

and the

optics has supplied astronomy with the telescope, thereby The enabling it to explore the depths of the heavens; and has telescope supplied biology with the microscope, thereby enabling it microto examine the minutest structure of the tissues.

scope.

of mathe

It may perhaps be mentally added by the reader that Connexion mathematics has become instrumental to dynamics and matics astronomy, by supplying them with methods and formule, with This is true, and a most important truth; but it is one of a different kind from the last mentioned. The connexion of optics with astronomy and with biology, through

dynamics.

the means of the telescope and the microscope, is only, as it were, accidental; that is to say, it does not depend on the nature of the sciences themselves. If this is not quite evident, it will become so on reflecting that it is conceivably quite possible, though unlikely, for a man to understand astronomy without understanding the theory of the telescope, or to be an accomplished physiologist without understanding the theory of the microscope. But the connexion of mathematics with dynamics and astronomy is of a different kind from this; for it would be impossible-impossible, I mean, in the sense of involving a contradiction-to understand dynamics and astronomy without understanding mathematics. The connexion of mathematics with dynamics and with astronomy (which is but a particular application of dynamics) is not in any sense accidental, but is grounded in the nature of dynamics. It would be impossible so much as to state the laws of dynamics without taking some of the truths of mathematics as known. Thus, to mention an elementary instance, it would be impossible to prove or to state the theorem of the parallelogram of forces without first knowThis kind ing the geometrical properties of the parallelogram. Now, of relation this kind of relation between sciences-namely, that in the basis which the truths of one presuppose those of another-is classifica the most fundamental of all relations, and is that whereon any rational classification or co-ordination of the sciences must be based.1 That is to say, we have to arrange the sciences in such an order that the truths of each science presuppose and depend on the truths of that science which comes before it in the series, and are independent ̧ of all those which follow it. Thus dynamics depends on mathematics, and mathematics does not depend on dynamics or any other physical science.

The laws of dynamicsimply those of mathematics.

is to be

of the

tion,

which is to be a series.

Such a

series is only

In classifying all the sciences, however, we cannot perfectly attain to such an arrangement as this: we can only possible. approximate to it. There is no possibility of so framing

approximately

1 I speak of this subject more briefly than I should otherwise do, in consequence of having gone into it in some detail in the chapter on Organic Subordination (Chap. XIII.).

an encyclopædia of the sciences that each separate science can be fully treated of without any anticipatory reference to those which are to follow it. For instance :-The chemical group of sciences, as I shall have to show, comes after the dynamical group, and is dependent thereon: electricity belongs on the whole to the dynamical group, yet the facts of electro-chemistry, as already remarked, belong as much to chemical as to electrical science, so that they cannot be explained or even stated without taking some of the facts of chemistry as known. The best arrangement of the sciences, however, is that in which the smallest number of such anticipatory references is needed; and we can approach much nearer to such an arrangement than could have been thought possible.

is from the

to the

special.

The value of this arrangement is greatly increased by The order the fact that it places the simplest and most general simple aud subjects first, and the more complex and special ones general after these; for the more complex and special subjects complex depend on the simpler and more general ones, but the and simple and general do not depend on the complex and special. Thus the facts of biology are more complex than those of chemistry; and they are also more special; for all substances have chemical properties, but only some substances are vitalized, or capable of vitalization. It is necessary to observe that, in speaking of the simplicity and generality of any set of scientific facts, I speak of the subject-matter of the science only, and not of its processes. The processes of mathematics are more intricate than those of chemistry; but the subject-matter of mathematics is perfectly simple and absolutely general, consisting in the properties of space and time: while the subjectmatters of chemistry are neither general nor simple; on the contrary, they are special, for every substance has its own peculiar properties; and they are so complex and varied that no complete enumeration is yet possible of the properties of any substance whatever.

What I have said on the subject of the classification Summary. of the sciences may be summed up in this formula :

No single

series in nature.

First division,

into logic and its applications.

Logic, unlike

The arrangement we are to aim at is that in which the more simple and general subjects come before the more complex and special, and in which each science depends on those which come before it in the series, but is independent of those which come after it. I think no intelligent man will question that, if it is practicable, such an arrangement is the right one. The question will be whether the sciences will fit into such an arrangement; and this is not a question for reasoning, but for trial. The only way of proving that such a classification can be made, is to make it.

I admit that there is no such thing, either in the classification of the sciences or anywhere else in nature, as a single linear series. All classification whatever is in groups of groups. But I think I shall show that the sciences do arrange themselves in a series of large groups, in which series the simpler and more general subjects come before the more complex and special ones, and each member of this series depends on those which go before it, but is independent of those which come after it.

Proceeding on these principles, the first and most fundamental division of the sciences is, as it appears to me, that into abstract logic on the one side, and the applications of logic on the other. Every possible science comes under one of these two heads: every science other than abstract logic consists in the application of logic to some particular class of subjects. In another way also logic is contrasted with the other sciences. All the other sciences are organa the other of discovery; that is to say, they make discoveries whereby sciences, we come to know what we did not know before. But organon. logic is not an organon of discovery. It has no discoveries to make. When we master the science of logic, we do not learn anything that we were ignorant of before; we only become conscious of knowing what we previously knew unconsciously. The axioms that a contradiction cannot be true, that what is true of every one of a class is true of each one of the class, and that things which

is not an

« السابقةمتابعة »