Auguste Comte and Positivism. Джон Стюарт МилльЧитать онлайн книгу.

1

See the Chapter on Efficient Causes in Reid's "Essays on the Active Powers," which is avowedly grounded on Newton's ideas.

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Mr Herbert Spencer, who also distinguishes between abstract and concrete sciences, employs the terms in a different sense from that explained above. He calls a science abstract when its truths are merely ideal; when, like the truths of geometry, they are not exactly true of real things – or, like the so-called law of inertia (the persistence in direction and velocity of a motion once impressed) are "involved" in experience but never actually seen in it, being always more or less completely frustrated. Chemistry and biology he includes, on the contrary, among concrete sciences, because chemical combinations and decompositions, and the physiological action of tissues, do actually take place (as our senses testify) in the manner in which the scientific propositions state them to take place. We will not discuss the logical or philological propriety of either use of the terms abstract and concrete, in which twofold point of view very few of the numerous acceptations of these words are entirely defensible: but of the two distinctions M. Comte's answers to by far the deepest and most vital difference. Mr Spencer's is open to the radical objection, that it classifies truths not according to their subject-matter or their mutual relations, but according to an unimportant difference in the manner in which we come to know them. Of what consequence is it that the law of inertia (considered as an exact truth) is not generalized from our direct perceptions, but inferred by combining with the movements which we see, those which we should see if it were not for the disturbing causes? In either case we are equally certain that it is an exact truth: for every dynamical law is perfectly fulfilled even when it seems to be counteracted. There must, we should think, be many truths in physiology (for example) which are only known by a similar indirect process; and Mr Spencer would hardly detach these from the body of the science, and call them abstract and the remainder concrete.

3

Système de Politique Positive, ii. 36.

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The strongest case which Mr Spencer produces of a scientifically ascertained law, which, though belonging to a later science, was necessary to the scientific formation of one occupying an earlier place in M. Comte's series, is the law of the accelerating force of gravity; which M. Comte places in Physics, but without which the Newtonian theory of the celestial motions could not have been discovered, nor could even now be proved. This fact, as is judiciously remarked by M. Littré, is not valid against the plan of M. Comte's classification, but discloses a slight error in the detail. M. Comte should not have placed the laws of terrestrial gravity under Physics. They are part of the general theory of gravitation, and belong to astronomy. Mr Spencer has hit one of the weak points in M. Comte's scientific scale; weak however only because left unguarded. Astronomy, the second of M. Comte's abstract sciences, answers to his own definition of a concrete science. M. Comte however was only wrong in overlooking a distinction. There is an abstract science of astronomy, namely, the theory of gravitation, which would equally agree with and explain the facts of a totally different solar system from the one of which our earth forms a part. The actual facts of our own system, the dimensions, distances, velocities, temperatures, physical constitution, &c., of the sun, earth, and planets, are properly the subject of a concrete science, similar to natural history; but the concrete is more inseparably united to the abstract science than in any other case, since the few celestial facts really accessible to us are nearly all required for discovering and proving the law of gravitation as an universal property of bodies, and have therefore an indispensable place in the abstract science as its fundamental data.

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The only point at which the general principle of the series fails in its application, is the subdivision of Physics; and there, as the subordination of the different branches scarcely exists, their order is of little consequence. Thermology, indeed, is altogether an exception to the principle of decreasing generality, heat, as Mr Spencer truly says being as universal as gravitation. But the place of Thermology is marked out, within certain narrow limits, by the ends of the classification, though not by its principle. The desideratum is, that every science should precede those which cannot be scientifically constitute or rationally studied until it is known. It is as a means to this end, that the arrangement of the phaenomena in the order of their dependence on one another is important. Now, though heat is as universal a phaenomenon as any which external nature presents, its laws do not affect, in any manner important to us, the phaenomena of Astronomy, and operate in the other branches of Physics only as slight modifying agencies, the consideration of which may be postponed to a rather advanced stage. But the phaenomena of Chemistry and Biology depend on them often for their very existence. The ends of the classification require therefore that Thermology should precede Chemistry and Biology, but do not demand that it should be thrown farther back. On the other hand, those same ends, in another point of view, require that it should be subsequent to Astronomy, for reasons not of doctrine but of method: Astronomy being the best school of the true art of interpreting Nature, by which Thermology profits like other sciences, but which it was ill adapted to originate.

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The philosophy of the subject is perhaps nowhere so well expressed as in the "Système de Politique Positive" (iii. 41). "Conçu logiquement, l'ordre suivant lequel nos principales théories accomplissent l'évolution fondamentale résulte nécessairement de leur dépendence mutuelle. Toutes les sciences peuvent, sans doute, être ébauchées à la fois: leur usage pratique exige même cette culture simultanée. Mais elle ne peut concerner que les inductions propres à chaque classe de spéculations. Or cet essor inductif ne saurait fournir des principes suffisants qu'envers les plus simples études. Partout ailleurs, ils ne peuvent être établis qu'en subordonnant chaque genre d'inductions scientifiques à l'ensemble des déductions emanées des domaines moins compliqués, et dès-lors moins dépendants. Ainsi nos diverses théories reposent dogmatiquement les unes sur les autres, suivant un ordre invariable, qui doit régler historiquement leur avénement décisif, les plus indépendantes ayant toujours dû se développer plus tôt."

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"Science," says Mr Spencer in his "Genesis," "while purely inductive is purely qualitative… All quantitative prevision is reached deductively; induction can achieve only qualitative prevision." Now, if we remember that the very first accurate quantitative law of physical phaenomena ever established, the law of the accelerating force of gravity, was discovered and proved by Galileo partly at least by experiment; that the quantitative laws on which the whole theory of the celestial motions is grounded, were generalized by Kepler from direct comparison of observations; that the quantitative law of the condensation of gases by pressure, the law of Boyle and Mariotte, was arrived at by direct experiment; that the proportional quantities in which every known substance combines chemically with every other, were ascertained by innumerable experiments, from which the general law of chemical equivalents, now the ground of the most exact quantitative previsions, was an inductive generalization; we must conclude that Mr Spencer has committed himself to a general proposition, which a very slight consideration of truths perfectly known to him would have shown to be unsustainable.

Again, in the very pamphlet in which Mr Spencer defends himself against the supposition of being a disciple of M. Comte ("The Classification of the Sciences," p. 37), he speaks of "M. Comte's adherent, Mr Buckle." Now, except in the opinion common to both, that history may be made a subject of science, the speculations of these two thinkers are not only different, but run in different channels, M. Comte applying himself principally to the laws of evolution common to all mankind, Mr Buckle almost exclusively to the diversities: and it may be affirmed without presumption, that they neither saw the same truths, nor fell into the same errors, nor defended their opinions, either true or erroneous, by the same arguments. Indeed, it is one of the surprising things in the case of Mr Buckle as of Mr Spencer, that being a man of kindred genius, of the same wide range of knowledge, and devoting himself to speculations of the same kind, he profited so little by M. Comte.

These oversights prove nothing against the general accuracy of Mr Spencer's acquirements. They are mere lapses of inattention,