I.
Let us first of all consider the characteristics of positive science. It has for its object the conversion of facts into laws, or in other words the resolving the composite into the simple, the particular into the universal, the contingent into the necessary. But let us observe with our author that we are only dealing here with a relative simplicity, a partial universality, a conditional necessity. None of these characters present themselves in a really absolute manner. The simple is invariably composed of several terms; the universal only applies itself to a certain class of phenomena; the necessary is so only with relation to the consequences of a law, but the law itself always remains contingent. Thus, no positive science can ever attain to the absolute. It is the same with methods. These methods are induction and deduction. Now, however precise these processes be, however marvellous the sequence and interdependence of the propositions they discover and demonstrate, their data are never more than particular and contingent facts; consequences, then, can only be proportioned to those data. Hence it is certain that the positive sciences cannot go beyond a relative universality or necessity. It may seem as though we ought to make an exception in favour of mathematics. But by a subtle discussion which it would be difficult to give summarily, the author shows that they too come under the same law, whence it follows that the domain of positive science properly so-called is contained within the relative.
From this consideration there has sprung up in our day a philosophy that reduces all sciences without exception to the knowledge of relation, and by so doing has declared all metaphysics impossible: and this philosophy is called Positivism. “Any proposition,” says Auguste Comte, “which is not finally reducible to the simple enunciation of a particular or general fact, is incapable of holding a real or intelligible meaning.” “There is nothing absolute,” says the same philosopher, “if it be not this very proposition that there is nothing absolute.” As to the proof of this proposition, it lies, according to the school in question, in the celebrated law which reduces all progress of the human mind in all orders of research to three phases: the theological phase, in which facts are explained by causes and supernatural agents; the metaphysical, in which they are explained by abstract and ontological entities; and, finally, the positive, in which phenomena are verified by experience and referred to their laws—that is to say, to constant and always verifiable relations of coincidence and succession.
Our author, having expounded this doctrine with much precision, proceeds to criticize it with equal sagacity. He points out what is illusory in this law of the three states; shows that it confuses metaphysic with scholasticism; and proves, finally, that, in aiming at merging mind in knowledge, and subordinating, as he says, the subjective to the objective, Positivism does not understand what it is speaking of, since all knowledge is ultimately referable to facts of consciousness—that is to say, to something subjective, which is in effect, as Descartes has pointed out, the only order of absolutely certain truths. Besides which, let positive science, or rather the positive philosophy, in the name of positive facts, proscribe metaphysic as it will, is it not evident that the fundamental conceptions of all science—number, atom, force, matter, cause, law—are metaphysical conceptions? Is it not evident that all science whatever is impossible without a certain number of principles or notions,—in a word, of intellectual laws, which even govern experience itself? As yet the positive school has not answered the learned demonstration of Kant on the necessity of the à priori principle, or rather it has ignored it. It has made no addition to that old empiricism which the school of Leibnitz and of Kant had refuted.
But since the Positivism of Auguste Comte, too little versed in metaphysical knowledge to discuss it authoritatively, there have arisen two important schools, the one of association, the other of evolution. The former has endeavoured to base experience on an experimental and positive law; the latter has generalized this law, and made of it a particular case of a more general law embracing the whole of Nature—namely, the law of evolution.
The doctrine of association may be referred to the fundamental law that all ideas rising simultaneously or successively in the human mind, tend invariably to recall each other in the same order; this is what is called association of ideas. When any two ideas have thus been constantly associated without ever being separated (as, for instance, form and colour), they unite indissolubly and thus become necessary laws. Now, of all these necessary connections, the most universal is this: no phenomenon ever appears without having been preceded by some other phenomenon, which is always the same under the same circumstances. This law is that of causality, which is both the supreme principle and, at the same time, the result of all experience. To this doctrine of J. S. Mill and Alexander Bain our author opposes the two following objections:—1st, How does it explain the generalization? 2nd, How does it explain the necessity of the laws of the understanding? On the first point the English School appeals to a law that it calls the law of similarity or faculty of identifying the like in the different. But this is indeed, strictly speaking, a fact of association? Should not association, properly understood, be reduced to the law of contiguity—that is to say, to the fact of our ideas only becoming associated through relations of time? To admit the faculty of recognizing similarity in diversity, what is this but to admit mind, intelligence—something, in short, which is other than a simple external association? As to the second point, can we reduce the rational necessity that Kant and Leibnitz have laid down as the criterion of à priori principles to a pure necessity of habit—that is to say, to the automatic expectation of the future inscribed on the past? Where is the scientific guarantee in this hypothesis? Why should Nature bend to our habits? “Who can assure us that we do not dream in thinking of the future, and that the next sensation may not interrupt our dream by an unforeseen shock?” We see how far-reaching this doubt is; it affects not only metaphysic but science as well.
As to the philosophy of evolution, we know that, with regard to the origin of the principles of thought, it consists in linking the experience of present generations to that of generations past; in substituting secular for individual experience—in a word, in filling up by the accumulation of ages on ages the interval existing between particular and contingent facts and the universality of principles. This hypothesis is always at bottom no other than that of the tabula rasa, only it is no longer the individual who is this tabula rasa, since each one has, by heredity, received a pre-formed intelligence. Nevertheless, under pain of contradicting the hypothesis, we are forced to admit that there was a first subject who, prior to the action of the object, must have been this tabula rasa. But here the objections of Leibnitz reappear. What can a pure, abstract, and unmodified subject be? And again, before any meeting of subject with object, we have to admit a pure object having nothing subjective, just as the subject had nothing objective. What shall we affirm of this pure object? Let us divest it if you will of colour, heat, sound; must we not at least conceive it as extended, as existing in time, conceive it, that is, according to the necessary forms that are supposed to be suppressed? For to say that it has been capable of existing without having anything in common with these forms, and that out of this unknown and nameless condition have arisen, by way of transformation, the notions of which we treat, were to admit that something can come out of nothing. We must therefore acknowledge that universal notions do at least exist as germs at the origin of evolution. It is not evolution that has created them, evolution has only developed them, and be they ever so attenuated, they still remain conditions without which nothing can be thought.
Such is the gist of the first part of M. Liard’s book, and we have nothing to add to it but our approbation. We can but admire the skilful analysis with which it begins, and the vigorous discussion accompanying that analysis. The three stages traversed by the experimental philosophy of our days—namely, Positivism, the Associative Philosophy, and that of Evolution—are competently and precisely summed up. The discussion is cogent, solid, and could not be further developed without injury to the unity of the work. No doubt it requires close attention to follow it; but it is lucid and well sustained. Whatever the difficulty metaphysic may encounter in constituting itself a science, and getting recognized as such, it has been established that empiricism is not a tenable position, since it has been found necessary to pass from positivism to association, from association to evolution; while evolution itself still supposed some pre-formation. One thing is certain, intelligence invariably contains a something that does not come from without—namely, intelligence itself.