Gianluigi Segalerba

At least since Sachs' well-known essay, readers of Plato's Republic have worried that there is a gap between the challenge posed to Socrates--to show that it is always in one's interest to act justly--and his response--to show that it is always in one's interest to have a just soul. The most popular response has been that Socrates fills this gap in Books Five through Seven by supposing that knowledge of the Forms motivates those with just souls to act justly. I offer some complaints about this gap-filling strategy and offer an alternative account, according to which there was never a gap. On my account, Socrates assumes that no one can have a just soul unless they have been raised well and that anyone who is raised well will act justly. On this view, the account of moral education in Books Two through Four is the key to understanding the connection between psychological and practical justice. I argue that this account makes better sense of what the Republic says, and that it attributes to Plato a more plausible moral psychology.

The focus of the book, which consists in three studies, can be described in the following aspects: Considerations on Aristotle's universals, reconstruction of Aristotle's critics to Plato' s ideas in Aristotle's lost work “On Ideas”, analysis of Aristotle's substance in the works Categories, Metaphysics, On the Soul, Posterior Analytics, Physics. My point of view is that Aristotle refuses every aspect of Plato's ideas in a radical way. I analyze Aristotle's conditions for a synonymy of predication and compare them with the condition for a not-homonymy of predication in the Argument from Relatives of “On Ideas”. My reflections on substance plead for the presence of a plurality of values of substance in the works of Aristotle: substance can be, for instance, the individual biological entity or the essence/nature/form of a biological entity; a coexistence of both values can be noticed in the different works of Aristotle

This study deals with the ontological position of predicated entities in comparison with the entities of which they are predicated of. Aristotle strongly criticizes, in some passages of his works, the interpretation that the predicated entities are entities which independently exist of the entities of which they are predicated. Aristotle opposes his interpretation of the universals as entities which does not independently exist, against Plato's ideas, which he interprets as independently existing entities. Aristotle's criticism of Plato's ideas is radical: he does not accept any characteristic of ideas and want them to be expelled from a sane ontology. Aristotle's ontology of instantiation, therefore, completely refuses Plato's ontology of participation.

This paper deals with the strategy of defence that Aristotle dedicates to the principle of contradiction; the analysis is concentrated on passages of Metaphysics Gamma 4. The main thesis of the paper is that Aristotle’s strategy is an ontological, and therefore not only a logical, one: the principle is defended on the basis of the, from an ontological point of view, unacceptable consequences which would arise in case of the absence of the principle itself. These consequences are, for instance, the disappearance of properties, of essences, of individual entities and of the plurality of essentially distinguishable entities, since the contents of the properties, the role of properties as essences and the constitution of the individual entities cannot hold, if the principle of contradiction does not hold. The principle of contradiction is, therefore, not only a logical principle: it is the ontological presupposition of the whole reality; without it there is no entity.

This essay is the first part of an analysis on the form and matter in the works of Aristotle. Within the whole analysis, I shall examine passages taken from different works of Aristotle that are relevant to the investigation on form and matter. In this essay, I shall focus exclusively on the chapter Metaphysics Zeta 3. The concepts of substance, matter, ontological subject, form, composite substance, this something and separated, which are consistently used by Aristotle within the development of the mentioned chapter, will be part of my survey of the contents of the chapter. The central argument of Metaphysics Zeta 3, which maintains the equivalence between substance and the feature represented by ontological subject, and which leads, through this first equivalence and through the equivalence between matter and ontological subject, to the result that matter is (the only) substance, will be investigated step by step so that all presuppositions, entailments, and consequences of the argument itself can be clearly shown. The problems which are caused by the mentioned equivalence of substance and ontological subject will be pointed out during my look at the chapter’s contents. In particular, Aristotle cannot accept that, in spite of the ontological subject being a correct feature of substance qua substance, substance is therewith reduced to matter. Being the ontological subject does not represent the only ontological feature of substance qua substance; the ontological features too of substance qua substance that are represented by being a this something and being separated belong to the concept of substance: they can never be forgotten within a right interpretation of substance. The identification of substance only with matter can never be accepted. Only the ontological values of substance represented by the form and by the composite substance possess the ontological features “being a this something” and “being separated”. Therefore, the ontological values of substance as form and as a composite substance must always be reckoned with in a correctly interpreted ontology. Neither of these values can be forgotten within an accurate inquiry of ontology. Hence, regardless of whether matter is substance and is correctly interpreted as substance, the values of substance as form and as composite substance must belong, in Aristotle’s view, to any right ontological system whatsoever. The plurality of values for substance, which I personally advocate, finds confirmation thanks to chapter Metaphysics Zeta 3: Matter, form, and composite substance all represent values for substance, despite the differences which they have as regards their own ontological features.

In my analysis I deal with some causes and origins of evil and of moral degeneration in the human dimension. My analysis focuses on Plato’s Republic. The origins and causes of the presence of injustice and of vice lie in the very structure of the human soul. The division of the soul into parts which are at least reciprocally independent of each other implies that there is the possibility that they are in conflict with each other. This is the origin of injustice and the root of every form of evil. The correct equilibrium among the parts of the soul, which, in my opinion, are to be interpreted as authentic potencies, can be achieved only by developing the rational part. This development requires a thorough education in philosophy. Throughout my analysis I quote passages in which Plato points out the presence of bad instincts and, in general, of a morally difficult component in our soul. The kind of soul considered in my analysis is the embodied soul.

The focus of the book, that consists in three studies, can be described in the following aspects: Considerations on Aristotle's universals, reconstruction of Aristotle's critics to Plato' s ideas in Aristotle's lost work “On Ideas”, analysis of Aristotle's substance in the works Categories, Metaphysics, On the Soul, Posterior Analytics, Physics. My point of view is that Aristotle refuses every aspect of Plato's ideas in a radical way. I analyze Aristotle's conditions for a synonymy of predication and compare them with the condition for a not-homonymy of predication in the Argument from Relatives of “On Ideas”. My reflections on substance plead for the presence of a plurality of values of substance in the works of Aristotle: substance can be, for instance, the individual biological entity (plant or animal) or the essence/nature/form of a biological entity; a co-existence of both values can be noticed in the different works of Aristotle.