Abstract

The monistic feature of metaphysical systems, arising out of a kind of human intrinsic feeling, has occupied the minds of thinkers since long ago. In fact, such systems have always sought for a constant and subsistent thing beyond all existing differnces and restlessness.Plato's philosophy is based on the following ideas: sensible objects are appearances rather than realities; they are merely the subject of conjecture rather than knowledge; and the subject of knowledge is the world of intelligibles.The specific theory of the Ideas is closely related to Plato's theory of the quality of man's knowledge and, considerning the fact that it views the world merely as appearance and seeks the truth in a higher and intelligible world, provides the essence for gnostic thought.In the process of the development of this idea, Mulla Sadra presents a new interpretation of the Ideas on the basis of the gradation of existence and the difference in perfection and imperfection. His interpretation could also be considered a natural outcome of his theory of the principiality of existence.