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.