The Ibn Sina's famous proof regarding to "suspended man" has been continuously considered by western thinkers. Many of western philosophers have formed their own similar ideas by use of this principle. One of the most outstanding examples of this idea is the Descartes' "Cogito". The similarity between these two principles has become a subject for many comparative works and studies among western and Islamic thinkers. Many of them have found so much resembles that they believe in causal relation between them. The purpose of this article is to examine briefly the situation of these two principles in their philosophical systems by investigating their objectives and foundation. Also, it tries to raise and answer the questions to what extent we can suppose their two principles in the same line of argumentation.
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