In the course of these seven years the philosophic development of the individual, preserving its correspondence with that of the race, will pass through its last phase. As the pupil passed before from Fetichism to Polytheism, so he will now pass, as spontaneously, into Monotheism, induced by the influence on his imaginative powers which hitherto have been supreme, of the spirit of discussion. No interference should be offered to this metaphysical transition, which is the homage that he pays to the necessary conditions under which mankind arrives at truth. There is something in this provisional phase which evidently harmonizes well with the abstract and independent character of Mathematics, with which the two first years of the seven are occupied. As long as more attention is given to deduction than to induction, the mind cannot but retain a leaning to metaphysical theories. Under their influence the student will soon reduce his primitive theology to Deism of a more or less distinct kind; and this during his physico-chemical studies will most likely degenerate into a species of Atheism; which last phase, under the enlightening influence of biological and still more of sociological knowledge, will be finally replaced by Positivism. Thus at the time fixed for the ultimate study of moral science, each new member of Humanity will have been strongly impressed by personal experience, with a sense of historical Filiation, and will be enabled to sympathize with his ancestors and contemporaries, while devoting his practical energies to the good of his successors. [Travels of Apprentices]