Renan assumed quite definitely a positivist attitude to metaphysics. “Philosophy,” he remarks, “is not a separate science; it is one side of every science. In the great optic pencil of human knowledge it is the central region where the rays meet in one and the same light.” Metaphysical speculation he scorned, but he admitted the place for a criticism of the human mind such as had been given by Kant in The Critique of Pure Reason.
Kantian also, in its professions at least, was the philosophy of Vacherot, who stated that the aim of his work, La Métaphysique et la Science, was “the reconciliation of metaphysics with science.”[[14]] These dialogues between a philosopher and a man of science, for of such discussions the book is composed, never really help us to get close to the problem, for Vacherot’s Kantianism is a profession which merely covers an actual positivism. His metaphysical doctrines are superimposed on a severe and rigid naturalism, but are kept from conflict with them, or even relation with them, by being allotted to a distant limbo of pure ideals, outside the world which science displays to us.
[14] See particularly his statements to this effect in his Preface, pp. xxxvii-xl.
Taine, in spite of his severely positive attitude, was a strong champion of metaphysics. The sciences needed, he claimed, a science of first principles, a metaphysic. Without it, “the man of science is merely a manœuvre and the artist a dilettante.” The positive sciences he re- garded as inferior types of analysis. Above them “is a superior analysis which is metaphysics, and which reduces or takes up these laws of the sciences into a universal formula.” This higher analysis, however, does not give the lie to the others: it completes them.
It was indeed a belief and hope of Taine that the sciences will be more and more perfected until they can each be expressed in a kind of generic formula, which in turn may be capable of expression in some single formula. This single law is being sought by science and metaphysic, although it must belong to the latter rather than to the former. From it, as from a spring, proceeds, according to Taine, the eternal roll of events and the infinite sea of things.
Taine’s antagonism to the purely empirical schools centres round his conception of the law of causality. He disagrees with the assertion that this law is a synthetic, a posteriori judgment, a habit, as Hume said, or a mechanical attente, as Mill thought, or a generalisation of the sensation of effort which we feel in ourselves, as was suggested by Maine de Biran. Yet he also opposes Kant’s doctrine, in which causality is regarded as a synthetic a priori judgment. His own criticism of Hume and Kant was directed to denial of the elements of heterogeneity in experience, which are so essential to Hume’s view, and to a denial of the distinction maintained by Kant between logical and causal relations. Taine considered that all might be explained by logical relations, that all experience might some day be expressed in one law, one formula. The more geometrico of Spinoza and the “universal mathematic” of Descartes reappear in Taine. He even essays in L’Intelligence to equate the principle of causality (principe de raison explicative) with that of identity.
His attempt to reduce the principle of causality to that of identity did not succeed very well, and from the nature of the case this was to be expected. As Fouillée well points out in his criticism of Taine, both in La Liberté et le Déterminisme and the concluding pages of his earlier work on Plato,[[15]] the notion of difference and heterogeneity which arises in the action of cause and effect can never be reducible to a mere identity, for the notion of identity has nothing in common with that of difference. Differences cannot be ignored; variety and change are undeniable facts of experience. Fouillée here touches the weak spot of Taine’s doctrine. In spite of a seemingly great power of criticism there is an underlying dogmatism in his work, and the chief of those dogmas, which he does not submit to criticism, is the assertion of the universal necessity of all things. To this postulate he gives a false air of objectivity. He avoids stating why we do objectify causality, and he diverts discussion from the position that this postulate may itself be subjective.
[15] Vol. 4.
The particular bearing of Taine’s psychology upon the general problem of knowledge is interesting. He defines perception in L’Intelligence as une hallucination vraie. His doctrine of the “double aspect,” physical and mental, recalls to mind the Modes of Spinoza. In his attitude to the difficult problem of movement and thought he rests in the dualism of Spinoza, fluctuating and not enunciating his doctrine clearly. The primacy of movement to thought he abandoned as too mechanical a doctrine, and regarded the type of existence as mental in character. Taine thus passes from the materialism of Hobbes to the idealism of Leibnitz. “The physical world is reducible to a system of signs, and no more is needed for its construction and conception than the materials of the moral world.”
When we feel ourselves constrained to admit the necessity of certain truths, if we are inclined to regard this as due to the character of our minds themselves (notre structure mentale), as Kant maintained, Taine reminds us that we must admit that our mind adapts itself to its environment. He here adopts the view of Spencer, a thinker who seems to have had far more influence upon the Continent than in his own country. Although Taine thus reposes his epistemology upon this basis, he does not answer the question which the Kantian can still put to him—namely, “How do we know the structure of things?” He is unable to escape from the difficulty of admitting either that it is from experience, an admission which his anti-empirical attitude forbids him to make (and which would damage his dogma of universal logical necessity), or that our knowledge is obtained by analysing our own thoughts, in which case he leaves us in a vicious circle of pure subjectivity from which there is no means of escape.