For a philosophic proposition, or definition, or system (as we have called it), appears in the soul of a definite individual at a definite point of time and space and in definite conditions. It is therefore historically conditioned. Without the historical conditions that demand it, the system would not be what it is. The Kantian philosophy was impossible at the time of Pericles, because it presupposes, for instance, exact natural science, which developed from the Renaissance onward. And this presupposes geographical discoveries, industry, capitalist or civil society, and so on. It presupposes the scepticism of David Hume, which in its turn presupposes the deism of the beginning of the eighteenth century, which in its turn is connected with the religious struggles in England and in all Europe in the sixteenth and seventeenth centuries, and so on. On the other hand, if Kant were to live again in our time, he could not write the _Critique of Pure Reason_ without modifications so profound as to make of it, not only a new book, but an altogether new philosophy, though containing within itself his old philosophy. Stiff with old age, he was even capable of ignoring the interpretations and developments of Fichte, and of ignoring Schelling. But to-day he could not ignore either of these, nor Hegel, nor Herbart, nor Schopenhauer. He could not even ignore the representatives of the mediæval philosophy, which followed the classical period of modern philosophy; the authors of positivist myths, Kantian and Hegelian scholastics, the new combinations of Platonism and Aristotelianism, that is, of pre-Kantian with post-Kantian philosophy, the new sophists and sceptics, the new Plotinians and Mystics, nor the states of soul and the facts, which condition all these things. For the rest, Kant truly lives again in our days, with a different name (and what is individuality, countersigned with the name, save a juxtaposition of syllables?) He is the philosopher of our times, in whom is continued that philosophic thought, which once took, among others, the Scoto-German name of Kant. And the philosopher of our day, whether he will it or no, cannot abandon the historical conditions in which he lives, or so act as to make that not to have happened which happened before his time. Those events are in his bones, in his flesh and blood, and it is impossible to drive them out. He must therefore take account of them, that is, know them historically. The breadth of his philosophy will depend upon the breadth of his historical knowledge. If he did not know them, but merely carried them in him as facts of life, his condition would not differ from that of any animal (or of ourselves in so far as we are animals or beings that are, or rather seem to be, completely immersed in will and practice). For the animal is precisely conditioned by the whole of nature and the whole of history, but does not know it. The meaning of the demand must therefore