نشریه پژوهش های هستی شناختی
پیاپی 12 (پاییز و زمستان 1396)

The problem of time travel has been recently dealt by philosophers as well as physicists. In the realm of philosophy, this problem is being discussed in metaphysics as well as the philosophy of action, the philosophy of language and ethics. According to Lewis’ definition, time travel will occur if the traveler’s personal time differs from the external time in magnitude. Some philosophers have found the idea of time travelling as impossible on the basis of some alleged paradoxes. In the contrast, some others have tried to solve these proposed paradoxes and endorsed the possibility of such a travel. In this paper, I examine a group of the most well-known paradoxes and their proposed solution. These paradoxes include the “nowhere paradox”, “the paradox of discrepancy”, “the paradox of backward causation”, “the paradox of changing the past” and so on. Eventually, I propose a new paradox as the paradox of identity. I conclude that in spite of some excellent theoretical efforts in order to solve these paradoxes, philosophers have much more to do to show the possibility of time travel.

Mulla Sadra was greatly influenced by Allamah Davani during his early years of thought. The Al-Mabda’ wa Al-Ma‘ad , “the Beginning and the End” is a witness of this impact. Mulla Sadra has written the first section of the book according to principality of the quiddity and tasting theosophy. The present paper proposes to demonstrate the theory of tasting theosophy through four basic axes in Mulla Sadra’s al-Mabda’ wa’l-ma‘ad. oneness of the necessary being and the way of confronting the Ibn Kammuna doubt or the paradox of multiple necessary beings, entity of the necessary and the possibilities, along with abstracting a single concept from contradictory affairs are some of the principles which mentioned above. A systematic comparison between Mulla Sadra and Allamah Davani’s views on the unity of the necessary existence reveals that Sadra has been influenced by Allamah Davani in the theory of tasting theosophy and expressing its preliminaries. Interestingly, none of the interpreters and translators of the al-Mabda’ Wa’l-Ma‘ad, have mentioned this influence. They all have neglected the fact that, Mulla Sadra at the time of writing the book, was believing in the tasting theosophy.

This article considers the place of ontology in Ingarden’s realistic phenomenology. Roman Ingarden, Polish phenomenologist, was a well-known student of Husserl. Ingarden has criticized the transcendental idealism directly or indirectly determined the course of most of his later philosophical work. Ingarden clearly saw Husserl as turning from the realism of the Logical Investigations to a metaphysical form of transcendental idealism by the time the first volume of Ideas was published. Ingarden in On the Motives which led Husserl to Transcendental Idealism criticizes Husserl's idealistic approach, namely, transcendental idealism. Ingarden's body of work revolves not around aesthetics, but rather around the realism/idealism problem — an issue that was to dominate his thinking ever since, as a young man, he recoiled against Husserl's transcendental idealism. But we also consider ontology of musical work in Ingarden’s phenomenology. He believes that musical work has purely intentional objectivity not real objectivity.

The present paper deals with the issue whether the concept of substance, can be considered as a genus and constituent of substantial species or it is an abstract and non- essential concept. Most of Muslim philosophers have defended the genus of substance, but some like Fakhr- e Razi maintain that substance is not a genus and constituent for substantial species, Mulla Sadra has advocated the substance as a genus and widely criticized the arguments which stated by the opponents. In this paper, first of all we will report the most important arguments of the opponents and then review Sadra's critics against them in detail to show that not only his criticism has not reduced the strength of its arguments, but also in many places, he has unconsciously strengthened the claims of the opponents. In the next step, two arguments supporting the genus of substance, one of them is demonstrated by Sadra and the other by Allameh Tabatabaeiare, are explained and then they put into assessment. finally, it is stated that the theory of regarding the substance as a genus has not been supported by any strong argument, whereas there are considerable arguments for denying that. As a result, we will survey that denying the genus of the substance will be led to the positive philosophical consequences, three of them will be discussed as following: a) new categorization of substances. b) removing ambiguity from substantiality of soul and the other simple things. c) eliminating the vagueness of substantiality of the Necessary being.

Alain Badiou, the French famous contemporary philosopher, considers ontology as identical with mathematics. He speaks about a kind of ontology entitled subtractive ontology which is based on pure multiplicity from which the one is subtracted. The fundamental claim of this ontology pertains to the mathematics of ontology. According to Badiou, this idea can be explained only by set theory. Within this ontological bed no reference is made to the meaning of being, nor sought to answer the question: “what is the nature of beings, as they are?” Instead, just like some great philosophers such as Leibnitz and Heidegger, in his philosophical struggle, he put the following question as his watchword: "why there are beings, instead of nonbeings?”. Undoubtedly, raising such question indicates the importance of nothingness in Badiou’s outlook. In this line, as void set plays a very important role in the set theory, nothingness is also important in subtractive ontology. In this paper, an attempt is made to study the notion of nothingness in Badiou’s ontology and highlight the importance of using mathematics to describe nothingness in this sort of ontology.

Philosophical demarcation regarding sensible and non- sensible world was always a distinctive among philosophers since the inception of philosophy. The result of such demarcation was to build two different kinds of philosophical grouping. On the one hand, there were the materialist philosophers who considered the limit of existence up to sensible beings and on the other hand, there was philosophers who hold that the limit of existence is extended beyond the sensible world as well. A significant distinctive matter in this regard is the method by which the discussion is settled. The aim in this paper is to deal with the method by virtue of which the question about the limit of existence could be dealt with. The writers attempt to reveal that in Plato and Avicenna`s view the method of investigation into sensible being was a common feature. The result displays that both philosophers took the method of investigation into sensible world in action with different metaphysical implication. Plato reached to Ideas and the world of Forms while the Avicenna resulted in natural universal which shared its existence with particular things in sensible world.

The articulation of Ibn Arabi’s school in 7th century made a huge revolution in bases of theoretical Gnosticism. Ibn Arabi's ontological worldview is based on 'God' and 'human'. The interpreters of Ibn Arabi's theories played a main role in developing his thoughts. The scholars like 'Sheikh Mahmood Shabestari', in parallel with practical Gnosticism, tried to develop Ibn Arabi's doctrines. The present study is an attempt to investigate the reflection of Ibn Arabi's ontological worldview in 'Golshane Raz' Masnavi with analytic-descriptive approach orienting three main axes: 'theology', religious anthropology', and 'individual unity of being'. The results of the research indicate that in Shabestari's thought, the manifestation has important place in self disclosure of the being. The relationship between God and existence is the same as relationship between manifest and manifestation. Among all theophanies in both worlds, "The perfect human" is the mirror of all God's names, a universe prescription, and "comprehensive detailing word". Sheikh Mahmood like Ibn Arabi considers Mohammadi’s truth as the first manifest truth, origin of universe appearance, reflection of God's beauty, final point of the saints, and manifestation of perfect human and his appearance reveals all God's truth and secrets. He believes that the knowledge of perfect human facilitates achieving to the higher levels of mystical knowledge, and knowledge of being makes Knowledge of God relying on thought of oneness of being and intuition; but intrinsic priority and posteriority between God and His manifestations and individuations, God's absolutism, and limitations of individuations make it impossible to know oneness being.

The aim of this paper is to study Existential principality proposing a new concept. Kierkegaard and Heidegger’s Ideas as two important philosophers of Existential philosophy have been studied. Existential authenticity in Kierkegaard and Heidegger’s doctrine has been investigated by using of comparative analytical method. The results show the authenticity is not exactly equivalent with individuality, but the existential authenticity is a multidimensional concept which indicates to the human lifestyle. Kierkegaard, Heidegger and other philosophers of existence in addition to emphasizing individuality and its importance in mass society, mention another components of authenticity including authentic communication, evading from formal orientation and mediocrity, Accountability and care about Existential angst. Although there are certain differences between them, but in the most cases the meaning of authenticity is the same. Finally, by studying the components of authenticity, a concept of existential philosophy has been proposed in this paper.