critique of the dogmatic presupposition of kant about the metaphysical problems impossibility of synthetic a priori propositions in ideal of pure reason area by mulla sadra philosophical system.

As we know, one of the most important problems which kant in his epistemological and philosophical system has dilled with it, is the proof of god by pure reason, that is, reason without any sensitive experience which is used for proving immaterial objects; because one of kant's most challenging issues is that he believes that theoretical knowledge is possible only in the realm of material, temporal and spatial objects; for this reason, in his viewpoint, the discussion of immaterial things such as soul and god, which are not temporal and spatial, is fundamentally wrong. to illustrate this mistake, kant in his transcendental dialectic section of the critique of pure reason, calls the idea of god the transcendental idea of pure reason, and claims that reason, neither empirically nor transcendently, succeeds in achieving transcendental ideas. because, he believes that intellect always tends to go beyond the realm of empirical affairs to extra-experiential affairs, while logically it is not possible for it to seek such superiority. kant, in the ideal of pure reason, negates the proof of the necessary being by following hume. so, he mentions only three theoretical arguments for proving god: (1. ontological argument; 2. cosmological argument; 3. theological, natural argument) then critiques all of them. this view is the consequence of kant's approach to epistemology and ontology. in epistemological approach, kant deals in detail with the possibility and truth of synthetic a priori propositions and believes that the possibility of a prior knowledge in metaphysics and physics depends on the possibility of synthetic a priori propositions. in fact, kant accepts the possibility and truth of these theorems in physics and mathematics, but argues that there is no logical way to these theorems in metaphysics. kant's theory of epistemology has principles which should be carefully examined and evaluated to determine which of them is acceptable and which of them is unacceptable. if the inadmissibilities are such that they shake the structure and foundation of the theory, it is obvious that another theory should be chosen. while, the perspective of mulla sadra, comes from his transcendent philosophy in another meaning, is contrast to kant’s view , because he not only does not believe in the closure of theoretical reason in metaphysics, but also believes that many philosophical issues, especially the existence of god, can be demonstrated from correct use of theoretical reason. according to sadra’s view, knowledge about the existence of god is the main goal of philosophy. despite of kant, he considers that the rational knowledge about god is possible and he puts forward various arguments to prove it. for example, he presented the siddiqin existential argument, as a way in which god is known by god, because in this argument, he tried to prove the necessary being at first and then the existence of other contingent beings in its light; through the thinking of existence itself and surveying its necessary rules. it is noticeable that the existential argument of mulla sadra should not be equated with the ontological arguments of anselm and descartes and others, which kant tried to criticize them by denying the existence as a predicate. kant's critique of the ontological argument does not enter into the siddiqin argument of mulla sadra, and this argument can be considered as a reliable and solid basis for rational proof of god. as a matter of fact, sadra's philosophy, both in the epistemological and in the ontological dimension, can resolve conflicts and fallacies of the ideal of pure reason..