The division of the soul and its perceptions are of the most important problems that attracted Ibn Sina`s interest. Ibn Sina held that there are three kinds of the soul: vegeterian, animal, and rational soul, among which only the rational one is immaterial. The main reason of its immateriality is its perception of the inteligibles. Other perceptions are somehow immaterial, that is, perception at the stage of the sense is not abstracted from the mater and its appendixes and at the (...) stage of imagination is abstracted from the mater and not from its appendixes and at the stage of intelligence it is abstracted from both mater and itsappendixes. And so this kind of perception is completely abstracted. Among philosophers who have discussed the problem of mind body distinction, there have been few philosophers who have presented certain proofs for the abstraction of the soul. But this issue was treated in Islamic philosophy. Moslim philosophers have extended the proofs of Plato's Phaedo and the best proof theirs proofs was the simplicity of perception that has been mentioned in Ibn Sina`s works. (shrink)