Abstract

This article is to analize the doctrines of two great philosophers, Descarets and Ibn-Sina on the soul.As he himself said, Descartes, while doubting on anything, was sure that " cogito ergo sum".He found this an unquestionable fact, therefore he took it as the first principle.After Descartes, some objections have been posed against his doctrine; for example the objection, posed by Ibn-Sina. Ibn-Sina believed that thinking is among the soul's acts, and the soul cannot be affirmed through one of its own acts; for, by the thinking, either the thinking in the universal sense of the term is meant or the thinking of a particular individual is meant; and in the latter case, it is absurd to go to find "the unknown"