The systematic focus of twentieth century logic and analytic philosophy on semantic paradoxes prompted the rediscovery of the nearly six hundred years of scholastic research devoted to paradoxes. The present paper focuses on the following three branches of scholastic logic: 1. definitions of semantic paradox; 2. basic strategies of solving paradoxes; 3. scholastic classifications of solutions to paradoxes. Scholastic logicians analysed paradoxes from threebasic points of view: the point of view of paradox-generating inferences, the point of view of paradoxical sentence, and the point of view of the theoretical context of paradoxes. These partial analyses can be synthesised into a coherent approach, allowing for analysing different aspects of semantic paradox.

In this paper, the authors show that there is a reading of St. Anselm’s ontological argument in Proslogium II that is logically valid (the premises entail the conclusion). This reading takes Anselm’s use of the definite description “that than which nothing greater can be conceived” seriously. Consider a first-order language and logic in which definite descriptions are genuine terms, and in which the quantified sentence “there is an x such that…” does not imply “x exists”. Then, using an ordinary logic of descriptions and a connected greater-than relation, God’s existence logically follows from the claims: (a) there is a conceivable thing than which nothing greater is conceivable, and (b) if x does not exist, something greater than x can be conceived. To deny the conclusion, one must deny one of the premises. However, the argument involves no modal inferences and, interestingly, Descartes’ ontological argument can be derived from it.

Receptive potencies are the essence in relation to the act of being (esse) and the matter in relation to the form. Suárez identifies the essence with the existence. A potential essence, according to Suarez, is nothing; therefore it cannot be receptive potency for being (esse). The actuality of an actual essence is its being (esse). Hence, the actual essence does not need to receive any further being distinct from it. Essence does not differ really from being (esse); nevertheless, we can conceive it without being. Essence as “whatness”, quiddity, is closely connected with concept and definition. In this regard we may make some critical remarks on Suarez’s doctrine: If the “whatness” is identical to the being (esse), this fact has to be reflected in the adequate notion of the “whatness”. If it is so, it seems that the essence conceived without being (esse) is not the same essence any more. Furthermore: If essence and existence are identified, what is it to which existence can be non-trivially ascribed? What is the receptive potency for being (esse)? Arriaga follows Suárez in the doctrine of essence and being, in his teaching on the prime matter however he goes even further. Whereas Suárez ascribes to the prime matter its own actuality, Arriaga assigns to it some attributes of substance. In contradistinction to the Suarezian conception of receptive potencies, the Thomistic doctrine of the relation of participation between potency and act permits metaphysics to withstand the threats of mechanicism and the post-fregean trivialization of the notion of being (esse).

Alvin Plantinga wrote a probabilistic critique of historical arguments for the kernel of Christianity. It is based on the fact that, generally, the more complex a conjunction, the lower its probability. The paper provides elementary insights into the epistemology of Plantinga, probability calculus, and the role of this calculus in contemporary epistemology. It introduces a concept of a good argument, explains in which sense and why, according to Plantinga, no good arguments for Christianity exist, and discusses the following replies. The probability that every argument for Christianity fails can be low. Even if Christianity is less probable than its proper propositional parts, it can be still be probable, whether on the same or on some enhanced body of evidence. Finally, there have been detailed probabilistic arguments for Christianity yielding results significantly different from Plantinga’s cursory estimates.

Aristotle’s notion of substance presents various problems of interpretation. Many interpreters focus mainly at the notion of primary substance, especially with regard to the difference between how Aristotle defines it in Metaphysics VII and in the Categories. The present study aims at confirming mutual compatibility of these texts and touches also the problem of knowability of the primary substance. Translation: Lukáš Novák

The article offers a critical biography, description and characteristic of method, fonts and doctrine of Master Paul of Soncino († 5 August 1495), friar of the Dominican Order, in particular his Acutissimae Quaestiones Metaphysicales. The life and work of this philosopher falls within the ambit of Italian Thomism of the 15th century. Between his masters we commemorate Peter Maldura of Bergamo and Dominic of Flanders. His exposition of Aristotle’s Metaphysic proceeds from a peculiar synthesis of Arabic Commentator Averroes and Thomas Aquinas. Soncinas’ work and position was frequently discussed up to the 15th century.

Two kinds of individuals are distinguished: abstract and concrete. Whereas abstract individuals belong to our conceptual sphere, concrete individuals (i.e. particulars) individuate the world of matter. A subject inquiring the external world projects abstract individuals onto the concrete ones (i.e. pieces of matter). Our theory offers a solution to various ontological and epistemological puzzles concerned with individuals, e.g., the Ship of Theseus, Polish Logician, problems with reidentification, or proper names.

The genuinely Aristotelian conception of possibilia (possible non-existing entities) does not admit their own potency to coming-to-be (“objective potency”), nor, consequently, does it ascribe any kind of “weak” existence to them. Nevertheless we can (and need) admit possibilia as legitimate objects of rational discourse. In its concluding part this paper proposes a definition of the logically possible, as well as a definition of the ontologically possible (which is possible not only because its notion is noncontradictory, but also due to the existence of its potential causes).

The aim of the article is to critically assess the widespread surmise according to which Descartes was in certain important aspects of his thought infl uenced by Suárez’s Metaphysical Disputations. In the article this question is addressed with regard to the problem of the ontological background of the representational acts of a finite mind. Descartes’ position is reconstructed on the basis of an analysis of Meditation III and consequently of Descartes’ polemic with Johan de Kater in the First Objections and Replies; the reconstruction is accomplished by means of terms and concepts commonly used in the late scholastic thought of the end of the 16th century. An analysis of the key passage of Section 2 of Disputation 54 of the Metaphysical Disputations of Suárez (concerned with the distinction between extrinsic denominations and beings of reason) then shows, first, that Suárez’s position concerning the ontology of mental representation does indeed agree with that of Descartes, not Kater; second, that the implications of Suárez’s critique of certain theses concerning the identity of extrinsic denominations and beings of reason probably form an important part of the conceptual framework presupposed in the polemic between Decartes and Kater.

Aristotle’s subtle distinction between the forms of friendship and his concept of loving friend as one’s other self propose a solution to the fundamental objection to any eudaimonian theory of slavery, namely that friendship – as basically non-moral phenomenon – is but an egoistic device of one’s happy life. Aristotelian theorems are based on his concept of analogy and on a philosophically specific notion of “self”. Since both of these are rooted in Platonism, Aristotle has toevolve them dialectically in a critical distance to Plato. Still, his dialectical theory of friendship needs to be rooted not in metaphysics but in political theory after all. Political friendship as a utopian perspective taken by each of the citizens in their pursuit of a close relationship with any other indicates a notion of “infinity as perfection” which presents the decisive step beyond Plato and toward the later course of the history of philosophy.

The present paper deals with the notion of essence in Thomas Aquinas. Part 1 focuses on the main points of Aquinas’s doctrine of essence set out in his De ente et essentia, and especially on the concept of essence as the “form of the whole” and the concept of the “nature considered absolutely”. The comparison with the teaching of Aristotle and Aquinas’s Arabic predecessors in Part 2 shows that Thomas’s notion of essence is an innovative re-interpretation, which he largely owes to Avicenna, of the original Peripatetic doctrine. Nevertheless, it is shown that this re-interpretation is to be understood as a result of Avicenna’s and Aquinas’s effort to provide a consistent explanation of various statements in Aristotle’s writings, not always compatible with each other.

This paper investigates Ockham’s claim that there is a diversity of suppositions of a mental term. First, it summarizes the hitherto research in Ockham’s theory of concepts (understood as natural signs) and the theory of mental language ascribed to him (Part 1–2). Secondly, it describes his theory of supposition, focusing on the interpretation of this theory which describes it as a device for interpretation of propositions (Part 3). Thirdly, the paper examines the problems which arise from combining Ockham’s theory concepts and his theory of supposition (Part 4–7) – namely, the problems concerning the nature of mental proposition, the questionof mental syncategoremata, and of equivocation in mental language. Part 8 then reveals the absurdity of understanding the supposition of a mental term as an instrument for interpretation of mental propositions. Finally, I propose a new interpretation of the whole issue, based on Ockham’s early commentary on the Sentences (Part 9). According to this interpretation, the diversity of supposition of a mental term is not triggered by the need of distinguishing various meanings of a mental propositions, but by Ockham’s nominalistic theory of science.