Andrzej Bułeczka

This thesis addresses three challenges posed by intentionality - the ability of our mental states and language to be about something - to a logician: an apparent reference to non-existent objects, intentional indeterminacy and the failure of substitutivity of coextensive terms in an intentional context. Since intentionality plays an important role in our everyday reasoning, a proper formal account of it is highly desirable, yet it requires a departure from classical logic. One can modify classical logic and adapt the formal apparatus to account for the aforementioned problems (Graham Priest’s logic for intentionality serves as an example of such an approach in this work) or one can make an even more radical shift and seek for inspiration in a different logical tradition like the terminist logic developed in the Late Middle Ages by figures like William of Ockham or John Buridan. The second path is explored here as a modest attempt to show that once we abandon the bias against the history of logic as irrelevant, we can actually get access to firm logical solutions inaccessible from a classical perspective, while still practising logic proper.

The aim of this study is to present in complete and accurate way one of the possible positions, i.e nondeflationary treatment of existence, in an interesting metaphysical dispute – the dispute over the status of existence. Moreover, the arguments and thesis from historically distinct periods are analysed to show that the knowledge of the history of philosophy is not a ballast. On the contrary, it can be creatively used in the contemporary discussion and deepen the understanding of this issue. The issue of the truth and the search for a proper description of reality has played a central role already in the very beginnings of philosophical research. However, reflection on the existence remained in the shadow of the drop-down theory of being and related theory of essence. At that time was developed (to the fullest extent expressed by Aristotle) a deflationary (reductionist) theory, according to which existence is not real, because it does not add anything to the essence which was identified with a being. Mere existence, as a part of reality that requires knowledge and examination, appeared later, in the era of flourishing Arab (Muslim and Jewish) and Latin philosophy, in the context of the philosophical study of the nature of God the Creator, who creates a whole reality out of nothingness. At that time the first metaphysical theories appeared, in which the existence was recognised as a real, irreducible element of reality. In this paper the history of extracting the non-reductionist theories of existence (in which it is treated as a real ‘component’ of being) is presented, with particular attention to the position of St. Thomas Aquinas as the creator of one of the most mature version of these theories. Subsequently, based on the example of the main representatives, the scholastic debate over the so-called ‘real difference’ (centred around the merits of maintaining the non-deflationary position) is shown. In the last section the contemporary debate over the existence is presented, with a focus on philosophers appealing (affirmatively or critically) to the theory of Aquinas. The presentation is mainly historical. Metaphysical theories, within which the status of the existence is recognised in different ways, are considered. The main point of reference is the doctrine of esse of Aquinas (as a blueprint for non-deflationary approach to existence), which is juxtaposed with the positions of other philosophers, i.e. with the classical (Aristotle, Godfrey of Fontaines) and contemporary reductionism (Frege, Russell, Quine, Kenny) and also other types of non-reductionist theories (Avicenna, Giles of Rome, Geach, Miller). The main conclusion is that the nondeflationary theory of Aquinas is coherent, plausible and still actual in XXI century.

Since the dawn of philosophy existence poses problems to philosophical analysis. At first, it seems that it is an obvious core of metaphysical theories. However, similarly as is the case of e.g. truth, talk about existence easily leads to a serious paradox: on the one hand it seems that the discourse about existence is superflous, redundant, on the other we have a well known problem of negative existential claims such as „Pegasus does not exist” or „There are no dragons”. Because of this troubles the dominating theory about existence was a redundant one, treating existence as (in contemporary formulation of Frege, Russell and Quine) second level property. In such a conceptual scheme to say that Socrates exists is merely to say that a property of being, which Socrates has an instance, is exemplified by something. In this paper I propose to move away from such a reductive vision of existence. On the basis of the considerations by P. T. Geache and B. Miller, I argue that one can meaningfully speak of the existence as a first level property (a property of the individual, real property), without falling into the paradoxes associated with the analysis of the negative existential propositions. Furthermore, existence should be granted the status of a primary and, at the same time, superior property of an individual, one which is gradable, open for determination by the object that receives it.