The subject of the present article is the analysis of fundamental logical-semantical terminology of late-medieval nominalistic logician Jean Buridan (c. 1295–1360). The analysis focuses on the concepts of truth conditions and logical consequence, whose clarification presupposes explication of modal terminology as well as a solution of semantical antinomies such as “Liar” (or an attempt to solve them). The analysis of Buridan’s argumentation suggests that Buridan’s project of logic actually fails due to several failures of conceptual analysis of semantical and modal terminology. An alternative solution of the question concerning logical consequence is thus proposed in terms of Buridan’s implicit (and unused) semantical conception of modalities that makes it possible to establish conceptually and therefore explicatively closed logical framework.

The author shows that Aquinas’s treatise on the Trinity can be viewed in two ways. According to the first, now prevailing opinion, the thoughts of the Angelic Doctor are too speculative and in essence they harm our personal relationship with God. He aims to show that the main source of inspiration for this approach are those currents in modern and contemporary philosophy according to which any metaphysics is impossible. Adherents of the other view do not reject metaphysics, and so they are also sympathetic towards Aquinas’s connecting speculation with the Trinity doctrine. They see a great advantage in this connexion, as it allows us to understand more deeply the mysteries of faith and so to demonstrate the uniqueness of the Christian message. The author aims to show that both approaches are justified and one should not be sacrificed for the other. He believes that a philosophical framework allowing the old and the new Trinitarian theologies to coexist is provided by Wittgenstein’s conception of speech games.

The paper deals with the conception of transcendental and categorial concepts in the work of Thomas Aquinas. As a starting point of the exposition the discussion of this matter in De veritate 1, 1 has been chosen, where Aquinas, drawing on Aristotle and Avicenna, determines which are the first concepts of intellect. The absolutly first concept, the terminus of conceptual analysis, is the concept of being (ens). All other concepts, both categorial and transcendental, result from conceptual addition to being. Aquinas’s conception of conceptual addition is explained in detail and used to illustrate Aquinas’s explication of individual transcendentals and categories. Finally it is shown, how Aquinas derives transcendental and categorial concepts as general and special modes of being (modi essendi) of being as such. Translation: Lukáš Novák

Starting from Aquinas’s natural law theory, the article discusses in which way one can ground an ethical theory relying on the concept of personal autonomy. This is possible because natural law, as a law of reason, determines the ends for which every individual human being reasonably may strive. In this context, it is also possible to justify the role of morality in human life. This is due to the nature of man as a social animal whose natural ends include a life in a human community. From this one can infer the two principles, not to harm others and to attribute his right to everybody. The application of those rules, as of any other rule of natural law, depends upon the person of the agent and his historical and social situation.

The article deals with the analysis of one medieval solution of semantic paradoxes, namely with the position of the so-called “cassantes” (i.e. “those who nullify”). The solution is based upon designating problematical sentences to be agrammatical and thus “saying nothing”: paradoxes are solved by means of deyning apparent truth-apts. Theoretically fundamental supposition of this step is drawing the distinction between grammatical and logical structure of a sentence, or (from a speech-act theoretical point of view) the distinction between a sentence and a statement. Remarkable analogies can also be shown between this distinction and the distinction between two conceptions of congruence in the twelfth-century grammar. Nowadays the cassationist approach is the solution of paradoxes proposed in the theoretical framework of the illocutionary logic.

Aquinas employs formal abstraction to secure the possibility of mathematics conceived as a theoretical Aristotelian science. Mathematics is a science that investigates real quantity and it grasps its necessary, universal, and changeless properties by means of formal abstraction. In accord with it the paper is divided into two parts. In the first part Aquinas’s conception of (formal) abstraction is explicated against the background of the Aristotelian theory of science and mathematics. In the second part the problems associated with formal abstraction in mathematics are critically assessed.

Leaving aside many of the topics present in the Peroutka vs. Novák (in)compatibilist exchange in this journal, I focus on the core claim of libertarianism: that the availability of alternative possibilities (AP) is a necessary condition of freedom of the will and freedom of action. Therefore freedom and moral responsibility for one’s action requires some indeterminacy in the moment of choice being present. Contrary to what Peroutka defends in his rational compatibilism I argue that compatibilist accounts of authorship and control are not sufficient to fulfil the sourcehood condition, acknowledged by them as necessary. I maintain instead, in light of contemporary incompatibilist literature, that alternative possibilities are also important for giving a convincing account of sourcehood. I further discuss the case of innate intuition of moral laws and actions being necessarily performed upon such intuition suggested by Peroutka. I consider several interpretations of this case and argue that the libertarian one, grounded on Robert Kane’s notion of self-forming actions, seems to be the most plausible.