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.

Modern philosophy of mathematics has been dominated by Platonism and nominalism, to the neglect of the Aristotelian realist option. Aristotelianism holds that mathematics studies certain real properties of the world – mathematics is neither about a disembodied world of “abstract objects”, as Platonism holds, nor it is merely a language of science, as nominalism holds. Aristotle’s theory that mathematics is the “science of quantity” is a good account of at least elementarymathematics: the ratio of two heights, for example, is a perceivable and measurable real relation between properties of physical things, a relation that can be shared by the ratio of two weights or two time intervals. Ratios are an example of continuous quantity; discrete quantities, such as whole numbers, are also realised as relations between a heap and a unit-making universal. For example, the relation between foliage and being-a-leaf is the number of leaves on a tree,a relation that may equal the relation between a heap of shoes and being-a-shoe. Modern higher mathematics, however, deals with some real properties that are not naturally seen as quantity, so that the “science of quantity” theory of mathematics needs supplementation. Symmetry, topology and similar structural properties are studied by mathematics, but are about pattern, structure or arrangement rather than quantity.

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.

In this paper I examine Aquinas’s commentary on a text of Aristotle in which the type of order between substance and accidents is discussed. I claim that Aquinas maintains that there cannot be any reference to sensibility, despite any prima facie interpretation of Aristotle’s texts, according to which it could be thought that substance is temporally prior to accidents and, hence, that we must presuppose a perceivable change in the world on the basis of which it is possible to consider something temporally prior to something else. This interpretation – which is possible on the basis of Aristotle’s texts – would be a misinterpretation, according to Aquinas. Aquinas’s assumption is philosophically worthwhile because it confi rms that every metaphysical proposition must abstract from sensibility.

John Mair (1467–1550) was an influential post-medieval scholar. This paper focuses on his Tractatus insolubilium, in which he proposed semantic analysis of self-referential phenomena, in particular on his solution to alethic and correspondence paradoxes and his treatment of their general semantic aspects as well as particular applications. His solution to paradoxes is based on the so-called “network evaluation”, i.e. on a semantics which defines the concepts of truth and correspondence with reality in contextual terms. Consequently, the relation between semantic valuation, synonymy and contradiction must be redefined.

The late scholastics, from the fourteenth to the seventeenth centuries, contributed to many fields of knowledge other than philosophy. They developed a method of conceptual analysis that was very productive in those disciplines in which theory is relatively more important than empirical results. That includes mathematics, where the scholastics developed the analysis of continuous motion, which fed into the calculus, and the theory of risk and probability. The method came to the fore especially in the social sciences. In legal theory they developed, for example, the ethical analyses of the conditions of validity of contracts, and natural rights theory. In political theory, they introduced constitutionalism and the thought experiment of a “state of nature”. Their contributions to economics included concepts still regarded as basic, such as demand, capital, labour, and scarcity. Faculty psychology and semiotics are other areas of significance. In such disciplines, later developments rely crucially on scholastic concepts and vocabulary.

The following paper discusses John of St. Thomas’ study of the way in which a habit (moral or epistemic virtue or vice) is a cause of an action it prompts. I begin with contrasting the question of causality of habits with the general question of the causal relevance of dispositions (2). I argue that habits constitute a very peculiar kind of dispositions marked by the connection with the properties of being difficult and being easy, and there are some special reasons to admit the irreducibility of dispositions of this kind. I argue also that there is a special sort of causal connection between a habit and an action it actually prompts. Then I present an analysis of four theses of John of St. Thomas on the causality of habits, which, I think, constitute the most mature and reliable study of the causality of habits in the scholastic tradition: (i) Habits are efficient causes of actions they prompt (3.1). (ii) Virtues do determine the very natures of actions they prompt (3.2); (iii) Virtues do not have a proper counterpart among the characteristics of actions they prompt (3.3); (iv) The formal object of causality of virtue is a masterpiece performance of an action (3.4). In my analyses of John’s arguments for these theses I make three claims: not all powers are “in state of readiness for action”; habits are powers of powers or dispositions of powers; the general concept of a strategy is the key to grasp the properties of being difficult and being easy, and habits should be analysed as a kind of strategies.

The relationship between body and mind was traditionally discussed in terms of immortality of the intellect, because immateriality was one necessary condition for the mind to be immortal. This appeared to be an issue of metaphysics and religion. But to the medieval and Renaissance thinkers, the essence of mind is thinking activity and hence an epistemological feature. Starting with John Searle’s worries about the existence of consciousness, I try to show some parallels with the Aristotelian Pietro Pomponazzi (1462–1525), and eventually show the Neoplatonic approach in Marsilio Ficino (1433–1499). The guiding question is: how can one philosophically address the problem of cognition in terms of corporeality and incorporeality? Searle maintains there is mind, although essentially related to a biological basis, and he is comparable to the Renaissance thinkers for his taking the interaction of the mental and the corporeal seriously.

An essential challenge of Aristotle’s Politics arises from the juxtaposition of contrasting and competing arguments in favour of virtuous monarchy, on the one hand, and the collective superiority of “the many”, on the other. This paper examines the purely theoretical reception of this contrast in the writings of some late medieval Aristotelians by focusing on a key section in Politics Γ (1280a8–1284b34). After reviewing Aristotle’s problematic position, the paper discusses its interpretation in the commentaries of Albert the Great, Thomas Aquinas/Peter of Auvergne and Walter Burley, as well as its use in the works of Giles of Rome, John of Paris and Marsilius of Padua. On that basis, finally, the paper outlines some general trends with regard to how medieval scholars dealt with Aristotle’s idea of the rule of the many as opposed to that of one or few virtuous persons.

Passages in Aristotle’s Politics Book 3 are cited in discussions of the “rule of law”, most particularly sections in 1287a where the famous characterization of law as “mind without desire” occurs and in 1286a where Aristotle raises and explores the question whether it is better to be ruled by the best man or the best laws. My paper aims, by exegetically culling out Aristotle’s position in the Politics, Nicomachean Ethics and Rhetoric, to argue that his view on the rule of law and its relations to human subjects is considerably more complex and considerably more interesting. Despite Aristotle’s dictum, laws are not expressions or institutions of a pure and passionless rationality, and in order to be framed, understood and administered well, one must both have the sort of solid understanding of virtues, vices, passions, and motives of human action that Aristotle’s moral philosophy provides and have developed, at least to some degree, certain virtues. My paper focuses particularly on three themes: the role of the passions and desires in judgment, action, virtues and vices; the inescapability of passions and desires in the functioning of law; the possibility for rule of law and a certain level of virtue to be mutually supporting.

John Mair (1467–1550) was an influential post-medieval scholar. This paper focuses on his Tractatus insolubilium, in which he proposed semantic analysis of self-referential phenomena, in particular on his solution to alethic and correspondence paradoxes and his treatment of their general semantic aspects as well as particular applications. His solution to paradoxes is based on the so-called “network evaluation”, i.e. on a semantics which defines the concepts of truth and correspondence with reality in contextual terms. Consequently, the relation between semantic valuation, synonymy and contradiction must be redefined.

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.

The kalām cosmological argument for the existence of God proposed by W. L. Craig (in 1970’s) has been subject to much debate on all sorts of issues related to the existence of God and the beginning of the universe. The goal of the paper is to briefly evaluate several complex questions embraced in the argument in order to show the depth and strength of the argument, and to avoid oversimplification, which one can find in some recent publications. The argument as such does not rely on a single thesis or a theory proposed by a single author. The argument has such a support from different fields that its opponents would need to elaborate a theory with much more explanatory power than the most recent cosmological theories.

Opusculum insolubilium is an anonymous sixteenth-century British logical treatise dealing with the so-called “insolubles”, i.e. self-reflexive paradoxical propositions. It summarises the fundamental principles of the approach proposed by Roger Swyneshed in the fourteenth century, which became popular in the British academic circles during the fifteenth century. The present paper has two basic aims: to contrive a modern edition of this treatise which could be used fora further research in post-mediaeval scholastic logic, and to provide elementary information about its content and historical context.

The article examines the first fruit of Leibniz´s philosophical endeavour, which is his baccalaureate thesis Disputatio metaphysica de Principio Individui, on thebackground of the comparison with Suárez´s conception of individual unity in his Disputationes Metaphysicae. Despite Suárez´s more differentiated attitude to the issue of individuation in general, the author is convinced that one can find strong parallels between both authors, namely the following: purely ontological treatment of the problem of the principle of individuation; search for a single principle which is common both to material and nonmmaterial substances; nominalist tendency, which is apparent not only in the positive statements of the two authors, but also in their criticisms of rival solutions in general, and theScotist conception in particular. The similarities are not limited only to the principle of individuation or to the problem of individual unity in general but they also extend to the problem of the distinction between essence and existence, the conception of transcendental unity and its relation to ens, or to the problem of reification of hylemorphic components of material substances.