Knowledge of existence is one of the significant issues in the domain of philosophy and mysticism, so that it is the pivot of these two disciplines. Both philosophers and mystics maintain that the subject of their discipline is ‘absolute existence’. This equivocation has caused some mistakes in the domain of mysticism and philosophy, especially the mistake of those who advocate Mulla Sadra’s philosophy; because when discussing the fundamentality of existence and its related issues, the Gnostics’ and the philosophers’ opinions are summoned by those advocates in favor of their own viewpoints, whereas there is no common characteristic between Sadraic ontology and Gnostic ontology. The reason is that within the realm of possible existence is Mulla Sadra’s principality of existence, which means the objective reality is the unmediated instance of the concept of existence, rather than the whitish concept, though as the philosophers have said: ‘Every contingent thing is composite duality, composed of quiddity and existence. However, what is in the Gnostics’ words meant by ‘absolute existence’ is Necessity Existence or God’s Existence. In this essay, the author attempts to make clear the differences of these two perspectives.

For Rumi the entire world of creation is the manifestation of the unique glory of God, in which God has revealed Himself in accordance with the creatures' capacities and faculties. Therefore, he describes the world as a mirror that constantly reflects the God's face. For him whole parts of the realm of existence are full of meaning and following his master, Shams Tabrizi, he believes that God is manifested in this very meaning. Rumi invites people to observe this meaning by purifying their minds and selves. Sometimes in Rumi's ontology the bipolar world changes into an indivisible and simple existence consisted of different levels. He sees no "discord" in the realm of existence but he describes the world as the place of "union" with God so every bit of it is full of meaning. Therefore from Rumi's viewpoint the realm of existence is full of joy and passion and every part of it goes through the way of perfection.

Many philosophers and logicians have contemplated the relationship between ontology and logic. The author of this paper, working within a Bolzanoan-Husserlian tradition of studying both ontology and logic, considers ontology as the science of the most general features of beings and the most general relations among them. He considers logic as the science concerning the most general statements of all (natural or artificial) languages and the most general relations among them from an inferential point of view. It is possible to see logic in a broader sense as the science of all kinds of relations among all kinds of entities, acts, and processes stating some (objective, subjective, artificial, or conventional) reality. These entities, acts, and processes are not individual, rather, they are idealized, such that their universals may be instantiated at all times and in all places. In formal ontology we search for the properties of those structures of the reality that are formally similar. So we may find some formal truths applying to all things and/or properties and/or processes in different areas of objective/subjective/fictional reality.Surveying briefly the most important relations of logic and ontology in both analytic and phenomenological traditions, the author focuses on this central point: If reality is one as the unity of more or less interconnected and interactive beings of all physical, nonphysical and artificial types, the system of inference too may be one as the unity of more or less interconnected statements of all natural and artificial types. The universal system of inference may be divided into several relatively separate subsystems (having a more or less degree of connection) just as the unified reality has divided into several relatively separate fields (having a more or less degree of connection and interaction). According to such a model for corresponding realities and sciences within the unified reality and the unified science, the author assumes the possibility of beginning to construct both the comprehensive system of reference and the comprehensive formal ontology, both covering all possible members of their own field and being parallel and correspondent to each other, a long-run work, of course, very difficult to do.

The article considers the ontology of spinosism. As is known, the great Dutch philosopher Benedikt Spinoza created a monistic philosophical doctrine, which later became widely known as spinosism. In Spinoza’s philosophical system, the comprehensive being is the substance or god. He defines substance as that which exists in itself and is conceived through itself. Spinoza, as one of the brightest representatives of pantheism, also calls the substance or god nature. In Spinoza’s pantheistic doctrine, nature is identified with God in the sense that nature is also absolutely independent and not conditioned, not created and eternal. In the opinion of Spinoza, the attributes of the god-nature are not influencing to each other thought and extension. According to Spinoza, single things, endless manifestations, all existing objects and subjects the modes of eternal substance or god-nature.

There is an ancient eager to know the truth of Being and to find an appropriate method for receive it appealing to reasoning or experience whether be experimental or mystical. Emerging rationalism, empiricism and intuitionism and so on has been the result of that efforts. Mulla Hadi Sabzevari, the famous commentator of Motaalieh School, has used several methods to analyze ontological issues and the article would focus on them, with a descriptive analytical procedure, to find which of them he most interested in. Research findings show that he did not satisfied to rational reasoning method even when he is engaging with philosophical issues in his works such as Description of Manzumah, Commentaries on Asfar, Commentaries on Shavahed al-Robubiah and Description on Divine Names and so on. Rather, Sabzevari with the help of a tasteful mystical method has connected the philosophical issues with issues  Love also plays fundamental role in creation and it is essentially the main source of creation.

What is the reality of meaning? Is it a subjective or an objective category, or is it a third one? What is the relation between meaning and usage? These are some key issues in the ontology of meaning. Knowing the reality of meaning is a basic step toward analyzing different propositions. Some Western philosophers of language consider meaning to be the same as an instance, and some others regard it as the relation between a word and its instance. John Luck thinks of meaning as a subjective idea, while some others look in the objective and behavioral expressions for meaning. Wittgenstein, in his earlier philosophical life, emphasized on the picture theory of meaning, while later on suggested the use theory (or instrumental theory) of meaning. John Austin accepted the use theory too.The author explains and evaluates different theories, and then brings up his own theory in this regard. He believes that meaning is the mental image itself, without taking its subjectivity into consideration. In other words, meaning is the same as the designated (or known) per essentia vis-a-vis concept and instance (known per accident).

The present paper aims at clarifying the role of the concept “walayah” in the philosophy of the unity of being in Islamic philosophy (wahdat al-wujud). The concept “walayah” is deeply built into the philosophic system of the Islamic theory of being, and moreover the dynamic aspect of this concept has always activated Islamic philosophy of existence and stimulated the thought of Islamic philosophers throughout history. The concept “walayah” is a concept intrinsic to the philosophic tradition of Islam which is not found in other philosophic traditions. For this reason, philosophic inquiry into the concept “walayah” will help us to have true insight into the essence of Islamic thought.

The ontology of daemons refers to the study of daemons while their "Minou and Giti" (spirit and body) have been interwoven and they are visible, strong and giants. The nature of their existence comes from the ontology of Ohrmazd (the uncreated God of Zoroastrianism), Amesh Spenta (a class of divinity that is Ahuramazda's incarnation) and Izadan (minor divinities), because in Mazdaism, the daemons, just like Ahriman (the great archrebel in Zoroastrianism) do not have existence. However, in national epics they will find heir own structures and are similar to the existence of human beings. Every daemon will have a name, feature, and personal characteristics that are making him a special character, separate from other daemons or human being. It is better to say their demonology (black body, giant feature and animalistic face) are coming from Ahriman characteristics, human imagination about the spiritual realm of daemons, the nomadic giant-like people, and magical elements. They also have ability to have metamorphosis, to transform their figures, to be corporal and to get human or animal shapes.