In a celebrated passage of his _Critique of Judgment_ the philosopher Kant had drawn attention to the necessity of bringing together the concept of freedom and the concept of nature as constructed by modern science, for the two were, he remarked, separated by an abyss. He himself felt that the realm of freedom should exercise an influence upon the realm of science, but his own method prohibited his attempting to indicate with any preciseness what that influence might be. The fatal error of his system, the artificial division of noumena and phenomena, led him to assign freedom only to the world of noumena. Among phenomena it had no place, but reigned transcendent, unknown and unknowable, beyond the world we know. The artificiality of such a solution was apparent to the thinkers who followed Kant, and particularly was this felt in France. “Poor consolation is it,” remarked Fouillée, in reply to Kant’s view, “for a prisoner bound with chains to know that in some unknown realm afar he can walk freely devoid of his fetters.” The problem of freedom, both in its narrow sphere of personal free-will and in its larger social significance, is one which has merited the attention of all peoples in history. France, however, has been pre-eminently a cradle for much acute thought on this matter. It loomed increasingly large on the horizon as the Revolution approached, it shone brilliantly in Rousseau. Since the Revolution it has been equally discussed, and is the first of the three watchwords of the republic, whose philosophers, no less than its politicians, have found it one of their main themes. The supreme importance of the problem of freedom in our period was due mainly to the need felt by all thinkers for attempting, in a manner different from that of Kant, a reconciliation between science and morals (_science et conscience_), and to find amid the development of scientific thought a place for the personality of the thinker himself, not merely as a passive spectator, but as an agent, a willing and acting being. Paul Janet, in his essays entitled _Problèmes du XIXe Siècle_,[2] treating the question of science, asks whether the growing precision of the natural sciences and “the extension of their ‘positive’ methods, which involve a doctrine or assumption of infallible necessity, do not imperil gravely the freedom of the moral agent?” While himself believing that, however closely the sciences may seem to encroach upon the free power of the human soul, they will only approach in an indefinite “asymptote,” never succeeding in annulling it, he senses the importance of the problem. Science may endeavour to tie us down to a belief in universal and rigid determinism, but the human spirit revolts from the acceptance of such a view, and acclaims, to some degree at least, the reality of a freedom which cannot be easily reconciled with the determinist doctrines. [2] Published in 1872.