all its stages and all its factors a non-material process. And it does not involve any serious error to maintain that the formula under which this doctrine obtained the widest acceptance by philosophy, while it best satisfied the craving of ordinary people for some insight into the nature of their mental operations, originated with Descartes. And this philosopher's well-known formula assumed: there exists a spiritual, non-extended, indivisible substance, an objective, immortal entity, superadded to and independent of brain, which thinks, feels, and wills—a substance cognizable by self-consciousness alone, and which is in fact the "thinking principle" or proper "soul." Mind thus becomes absolutely and wholly an extra-cerebral product, and the possible offspring of activity on the part of the "soul" alone. The purely hypothetical character of this doctrine, the feeble, in some sense half-hearted, support given it by its originator, its incompatibility with every-day experiences of cerebral disease, and its proving a hopeless puzzle to cultured people, at once endowed with the critical faculty and unbiased by prejudice, all alike failed to shake its supremacy, and for long years it held sway, not as a makeshift, provisional, mere scholastic formula, but as an established primary truth. And all this, though Descartes himself, in the following words, honestly avowed his disbelief in the surety of his own doctrine: "Je confesse," he writes, "que par la seule raison naturelle nous pouvons faire beaucoup de conjectures sur l'âme et avoir de flatteuses espérances, mais non pas aucune assurance" (I confess that by natural reason we can make many conjectures about the soul, and have flattering hopes, but no assurance).
Meanwhile, as mind was thus made a product of the soul, the question at once arose by necessary involution. What in turn was the soul? Now, in all probability, no more startling chapter figures in the history of philosophy than that chronicling the varied efforts made at furnishing a sufficing reply to this query. From the days of Plato to our own, metaphysicians seem to have lost themselves in a maze of conjectures, too often, unfortunately, no less dogmatic in tone than vague and unsatisfactory in essence. Yet be their failures, while unflinchingly registered, freely forgiven; the obscurity of the problem to be solved, coupled with the imperfection of the instrument selected for its solution, has ever proved an obstacle to success, even when that instrument has been handled by the deepest thinkers and most devoted searchers after truth.
Thus, setting aside the profanum vulgus of illogical and inaccurate writers, with whom the word is but a word, carrying with it no inkling even of definite signification, we find that with some philosophers
- In explanation of his doubtingness, we must remember Descartes was not merely a metaphysician—he was likewise a physicist of high distinction. The positive tendencies fostered by physical objective study served to counterbalance within certain limits the subjective transcendental activity of his grand intellect.