It is known that Ibn Sina Has mentioned three arguments to prove the NECESSARY of EXISTENT, that is the argument from causality, from movement, and the argument from necessity and possibility. With a little reflection, it becomes clear that none of these arguments are Ibn Sina's innovative demonstration and are clearly stated in the works of Aristotle, Kindi and Farabi. What is Ibn Sina's original demonstration in proving the necessity of existence is the argument that is requisite for his philosophical system, that is, the demonstration based on the rational analysis of "existence" which can be called the Ibn Sinai demonstration. Ibn Sina, by rational analysis of existence as rational truth, proves the being of NECESSARY EXISTENT and divine attributes and actions. Whereas in the above three proofs, with the presumption of possible existence, God is proved. In this article, we show with arguments and the evidences that Ibn Sina's main and innovative argument is based on his theory about existence. Existence in Ibn Sina's thought is a metaphysical and a priori truth. contemplating on Ibn Sina's theory about existence makes it clear that his argument is not of Anselm and Descartes' argument and is not subject to Kant's criticism. On this basis, Ibn Sina is the first to present an EXISTENTial argument that, while preceding philosophers such as Anselm, is also significantly different from them.

There are principles in Islamic Philosophy which serve as evidence in favor of the view that Muslim philosophers understand NECESSARY EXISTENT to be “ personal” . The principles include “ division of beings into NECESSARY and contingent while accepting univocity of existence” , “ The demand of NECESSARY EXISTENT for evidence” , “ univocity of NECESSARY EXISTENT’ s attributes and those of contingent beings” , “ application of personal beings’ predicates to NECESSARY EXISTENT” , “ understanding revelation as speech” , “ personal account of God in the course of prayer” , etc. There are, however, some other pieces of evidence that indicate impersonality of NECESSARY EXISTENT, e. g. “ Theory of Emanation” , “ pure simplicity of NECESSARY EXISTENT” , “ Infinity of NECESSARY EXISTENT” , “ Apophaticity in religious language” , and “ denial of independent existence of caused being” . The latter pieces of evidence show, at least, that there is an ambiguity in understanding whether the concept of NECESSARY EXISTENT in Islamic philosophy indicates an (im)personal God. At most, they demonstrate that the concept of NECESSARY EXISTENT in Islamic philosophy is more compatible with an impersonal notion of God. In this article, while giving some points on the strong claim, I shall argue for the weak one.

In this article, by an introduction about the importance of recognition of existence, I proceed to existence as a common subject between philosophy and gonastism. The subjects of existence is the most obvious concept and also the most comlex fact in metaphysics. In this article also pointed to the Molla Sadra"s views about the existance and his several profound questions about the significance and recognition of existence... seven reasons from the last chapter of Tahrir -al- Tamhid and reasonof piouses has been explained briefly. Another part of this article is the viewpoints of professor Assar about existence and Ayatolah Rafiee Ghazvini about the EXISTENT unity. This article is an introduction to the proposal of research about Ibn Arabi and late Imam Khomeyni" s viewpoints which we are going to explain them later.

Although the philosophical system of Ibn Sina is a purely intellectual one that many of its underlying principles is constituted by the principles of Aristotelian philosopy and his philosophy is called "peripatetic philosophy", but Ibn Sina never commits himself to the preservation of all the principles of Aristotelian philosophy and in many cases criticises them. By accepting some Aristotelian principles and presenting his own philosophical principles, Ibn Sina is considered the founder of Islamic prepatetic philosophical system which is a philosophy based on EXISTENT.He regards the object of his metaphysics EXISTENT qua EXISTENT and founds his metaphysical principles of the basis of that concept.Throughout the history besides Ibn Sina many of the philosophers after him as well in the Islamic world and in the west consider the object of metaphysic as EXISTENT qua EXISTENT, but it does not mean at all that all these philosophers have a single metaphysical structure. In the philosophy of Ibn Sina EXISTENT is a univocal concept which by anological gradution applies to its exemplifications. The concept of EXISTENT qua EXISTENT is so universal and comprehensive that all the objects in the universe are the extentions and denotations of it.The wide scope of EXISTENT qua EXISTENT include all creatures, from the blessed and exalted God to abstract possibilities and then corporeal possibilities and at last at the lowest level of existence, the primary matter.Among these EXISTENTs God has a pure self subsitent existence, depends on no other being and by contrast possible being have a correlative and dependent existence on neccessary beings and in their existence and survial need neccessary being.

Tajrid al-I'tiqad by Nasir al-Din Tusi is one of the most important educational texts in Islamic Theology, and many commentaries and glosses have been written on it. One of the most significant commentaries is the one written by Qushji and the annotations by Khafri on this commentary. Alavi also wrote three commentaries on Khafri's gloss, one of which is Hazirat al-Uns. The main question of this study is: "was Ahmad Alavi successful in his EXISTENTial approach to Khwaja's proof for the NECESSARY EXISTENT in the interpretation of Hazirat al-Uns? " The findings of this article are as follows: 1. Alavi tries to present Khwaja's proof as a demonstrative proof (burhan-e limmi) centered on an EXISTENTial approach and focused on existence. 2. The separation of the self-existence of the major premise from the relational existence of the major premise and, consequently, the non-necessity of the major premise in essence, and its need for a cause in a certain quality or an accident of the major premise, can only be discussed when the predicated existence is other than the NECESSARY EXISTENT. Since the NECESSARY EXISTENT is NECESSARY in its essence, it is NECESSARY in all its attributes and states and has no state of expectation or need. 3. Although Alavi discusses existence and the absolute EXISTENT in *Hazirat al-Uns* and states that considering existence is different from considering contengency, what he ultimately engages with is an EXISTENT that is divided into two categories: the NECESSARY and the contingent. This divisibility and separation are a characteristic of a mental concept, not an objective reality.

Generally speaking, Islamic philosophy is the legacy of Greece and is modeled on Aristotle's works in particular. Like the collection of his philosophical works, it consists of logic, general metaphysics, physics, theology, and practical wisdom. Concerning the definition and subject of philosophy, following the Aristotelian tradition, Islamic philosophy has referred to "EXISTENT qua EXISTENT" and "separate substances" and posed the discussion of whether each is separately the subject of philosophy, and whether they are the same as each other or one includes the other. Moreover, it asks how, if the former is true, this sameness is justified, and if the latter is true, which is general and which is particular.In all the philosophical systems of the East and the West, these two issues, that is, the accidents of EXISTENT qua EXISTENT and separate substances are mixed with each other and cannot sometimes be separated from each other. However, in Islamic philosophy, particularly after Mulla Sadra, they were separated from each other under the titles general theology and particular theology or theodicy. However, both are subcategorized under the all-inclusive title "prime philosophy" or theology. There have also been debate concerning the scientific borderlines between the two issues; nevertheless, they have not led to any conclusions in practice. This paper deals with a methodological demarcation between them.

In the fourth subpart (namat) of Kitāb al-Ishārāt wa-l-Tanbīhāt, Ibn Sīna tries to prove the existence of a particular being, named “NECESSARY EXISTENT”. There he also explains the central role of this being in the world, His relation to other beings, and His attributes. It is in this very framework that he discusses other beings, that is, only to glorify the “NECESSARY EXISTENT”. Ibn Sīna believes that the “NECESSARY EXISTENT” is the cause of existence and makes things exist. In his ontology, the possible EXISTENTs, i.e. everything except the NECESSARY being, are considered to be “caused”. In view of this, in the fourth subpart of Kitāb al-Ishārāt wa-l-Tanbīhāt as well, everything other than the “NECESSARY EXISTENT” has been taken into consideration only as a caused thing or an effect.

This paper offers a new reading of Avicenna’s al-Ishārāt wa-l-Tanbīhāt. It argues that this work, despite its brevity, is not a mere summary of Avicenna’s philosophy but rather his attempt to present a distinctive “pre-physics” or a purely rational metaphysics. In al-Ishārāt, Avicenna deliberately engages with philosophical questions that can be addressed solely by rational analysis, without recourse to empirical observation or the study of nature. Thus, logic and physics in this work serve primarily as methodological foundations for a metaphysics established a priori. The metaphysical discussions in al-Ishārāt include topics such as self-awareness, the proof of the NECESSARY EXISTENT, its attributes, and its acts. Within this framework, the thought experiment of the “Flying Man” plays a central role in grounding Avicenna’s rationalist epistemology and his pre-natural metaphysics. Beginning in the third namat, Avicenna articulates his rationalist approach, which develops into a metaphysical system encompassing the proof of the NECESSARY EXISTENT, its attributes, its immediate causation, and the emanative order of intellects and celestial spheres. In the later namats, Avicenna also discusses human felicity, which he identifies with the perfection of the Flying Man or the intellect in its disembodied state.