A dissertação examina a relação entre conhecimento e sensação, sensação e pensamento, ser e perceber segundo Protágoras, Platão e Aristóteles, com o objetivo de mostrar o que é a percepção segundo o paradigma sofístico e o platônico e, por fim, qual é o lugar da tese aristotélica sobre a percepção diante desses dois paradigmas. Como resultado da investigação, temos que, para Aristóteles, diferentemente de Protágoras, a sensação não é responsável por todos os julgamentos, nem por discriminar todos objetos cognoscíveis; também para Aristóteles e diferentemente de Platão, o extremo oposto não é verdadeiro, a saber, que a sensação não discrimina seus próprios objetos. Conhecimento e sensação, portanto, não devem ser idênticos ou distintos de modo absoluto, nem o ser é absolutamente ser percebido, nem o ser percebido é absolutamente indeterminado, mas, para Aristóteles, o ser é, em parte, percebido e determinado pela faculdade perceptiva e, em parte, conhecido pelo intelecto. A dissertação, deste modo, pretende elucidar como o ser é conhecido pela percepção segundo Aristóteles, tratando assim de um ponto extremamente controverso, a saber: como a sensação discrimina seus próprios objetos sem a intervenção do pensamento, se tal discriminação resume-se apenas em processos fisiológicos ou é também uma atividade da alma e, se é também uma atividade da alma, em que sentido a alteração física ocorrida no corpo, conjuntamente com uma certa atividade da alma, constituem a percepção. / The dissertation investigates the relation between knowledge and perception, perception and thought, to be and to perceive according to Protagoras, Plato and Aristotle with the objective to show what is perception according to the sofistic and to the platonic paradigm and, finally, what is the place of the aristotelian thesis of perception in relation to these two paradigms. As a result of the investigation, we conclude that, for Aristotle, and differently from Protagoras, the perception is not responsable for all judgments, neither is responsable to discriminate all cognitive objects. Furthermore, for Aristotle and differently from Plato, the extreme opposite is not true, i.e., that perception does not discriminate its own objects. Knowledge and perception, therefore, must not be absolutely identical or distinct, neither the being is absolutely being perceived, neither the being perceived is absolutely indeterminated. However, according to Aristotle the being is, somehow, perceived and determinated by the perceiving faculty, and, somehow, known by the intelect. In this way, the dissertation intends to clarify how perception knows the being according to Aristotle by treating a very controversial point: how perception discriminates its own objects without the thought\'s intervention, if this discrimination is strictly a physiological process or is also an activity of the soul, and if it is also an activity of the soul, in which way the body\'s physical alteration conjoined with a certain activity of the soul constitute perception.

A dissertação examina a relação entre conhecimento e sensação, sensação e pensamento, ser e perceber segundo Protágoras, Platão e Aristóteles, com o objetivo de mostrar o que é a percepção segundo o paradigma sofístico e o platônico e, por fim, qual é o lugar da tese aristotélica sobre a percepção diante desses dois paradigmas. Como resultado da investigação, temos que, para Aristóteles, diferentemente de Protágoras, a sensação não é responsável por todos os julgamentos, nem por discriminar todos objetos cognoscíveis; também para Aristóteles e diferentemente de Platão, o extremo oposto não é verdadeiro, a saber, que a sensação não discrimina seus próprios objetos. Conhecimento e sensação, portanto, não devem ser idênticos ou distintos de modo absoluto, nem o ser é absolutamente ser percebido, nem o ser percebido é absolutamente indeterminado, mas, para Aristóteles, o ser é, em parte, percebido e determinado pela faculdade perceptiva e, em parte, conhecido pelo intelecto. A dissertação, deste modo, pretende elucidar como o ser é conhecido pela percepção segundo Aristóteles, tratando assim de um ponto extremamente controverso, a saber: como a sensação discrimina seus próprios objetos sem a intervenção do pensamento, se tal discriminação resume-se apenas em processos fisiológicos ou é também uma atividade da alma e, se é também uma atividade da alma, em que sentido a alteração física ocorrida no corpo, conjuntamente com uma certa atividade da alma, constituem a percepção. / The dissertation investigates the relation between knowledge and perception, perception and thought, to be and to perceive according to Protagoras, Plato and Aristotle with the objective to show what is perception according to the sofistic and to the platonic paradigm and, finally, what is the place of the aristotelian thesis of perception in relation to these two paradigms. As a result of the investigation, we conclude that, for Aristotle, and differently from Protagoras, the perception is not responsable for all judgments, neither is responsable to discriminate all cognitive objects. Furthermore, for Aristotle and differently from Plato, the extreme opposite is not true, i.e., that perception does not discriminate its own objects. Knowledge and perception, therefore, must not be absolutely identical or distinct, neither the being is absolutely being perceived, neither the being perceived is absolutely indeterminated. However, according to Aristotle the being is, somehow, perceived and determinated by the perceiving faculty, and, somehow, known by the intelect. In this way, the dissertation intends to clarify how perception knows the being according to Aristotle by treating a very controversial point: how perception discriminates its own objects without the thought\'s intervention, if this discrimination is strictly a physiological process or is also an activity of the soul, and if it is also an activity of the soul, in which way the body\'s physical alteration conjoined with a certain activity of the soul constitute perception.

Mon travail de thèse a comme objectif de reconstituer la théorie du vivant d’Épicure en clarifiant la relation entre l’âme et le corps. Autrement dit, je vise à comprendre l’explication épicurienne du vivant en vérifiant comment et en quelle mesure l’âme et le corps sont impliqués dans les phénomènes vitaux comme le sommeil, la respiration, la digestion, etc. Pour ce faire : 1) dans la première partie je reconstitue la doctrine psychologique à travers les écrits d’Épicure (Lettre à Hérodote et livre XXV du Peri Physeos), les témoignages épicuriens (notamment Lucrèce mais aussi Démétrius Lacon et Diogène d’OEnoanda) et anti-épicuriens (Cicéron, Plutarque, etc.) ; 2) dans le deuxième partie j’examine le développement de la psychologie, telle que je l’ai reconstituée, sur la base d’une comparaison dialectique avec Démocrite et Aristote ; 3) dans la troisième partie je reconstitue la théorie physio-biologique à partir du livre IV du De rerum natura en montrant ses liens avec la théorie psychologique et je confronte les explications épicuriennes des phénomènes psychobiologiques avec les explications provenant du milieu atomiste, péripatéticien et médicale ; 4) dans la quatrième partie je ferai une comparaison entre les théories psychobiologiques d’Épicure avec celles d’Asclépiade de Bithynie en confrontant leur application dans l’explication des maladies. / My thesis aims at providing an explanation for the Epicurean theory of the living being by accounting for the relationship body and soul entertain in psycho-biological phenomena. In other words, the aim of this thesis is to investigate in which manner and to what extent both the body and the soul are involved in vital phenomena such as sleep, breathing, digestion etc. To this purpose, sections 1 and 2 will deal more closely with Epicurus’ psychological doctrine, while sections 3 and 4 will integrate the discussion with Epicurus’ account of (psycho-)biological phenomena. Accordingly, section 1 will provide a reconstruction of Epicurus’ psychological doctrine through an analysis of Epicurus’ own writings (Letter to Herodotus; Book XXV of the Peri Physeos), Epicurean testimonies (including Lucretius but also Demetrius Lacon and Diogenes of OEnoanda) and anti-Epicureans accounts (Cicero, Plutarch, etc.). Section 2 will offer a dialectical explanation for the development of Epicurus’ psychology (as reconstructed in section 1) in its relationship with the previous philosophical background, Democritus and Aristotle specifically. Section 3 will consider the physio-biological theory from book IV of the De rerum natura and will acknowledge the links this entertains with Epicurus’ psychological theory. In this context, Epicurean explanations of psycho-biological phenomena will be compared with those offered by the atomist, Peripatetic and medical milieu. Lastly, section 4 will offer a comparison between Epicurus’ psycho-biological theories and those of Asclepiad of Bithynia and will examine their respective application in the context of explaining diseases.

Les lecteurs du traité De l’âme d’Aristote pensent souvent que la véritable contribution du Stagirite en ce domaine consiste dans l’application de l’hylémorphisme à la relation de l’âme et du corps. Le rôle que jouent les notions de puissance et de réalisation dans la psychologie aristotélicienne est relativement négligé au profit de celui des notions de matière et de forme.L’objectif de cette étude est de mesurer les contributions respectives des deux couples conceptuels fondamentaux de l’ontologie aristotélicienne à l’étude de l’être animé. Quelles sont la portée et les limites de l’hylémorphisme psychologique ? Quel rôle joue la distinction des niveaux de puissance et de réalisation dans le DA et dans d’autres traités consacrés à l’être animé ? Par quels moyens conceptuels Aristote parvient-il à définir l’âme, à résoudre les problèmes de la relation de l’âme et du corps, à unifier ses recherches psychologiques et zoologiques ? A travers l’examen de ces questions, cette étude cherche à préciser la place qu’occupe le notion de « réalisation première » dans l’étude aristotélicienne de l’âme et de l’être animé. / Readers of Aristotle’s De anima often hold that the tenor of his account consists in the application of hylomorphism to soul-body relations. The part played by potentiality and actuality in Aristotle’s psychology has been somewhat overlooked while hylomorphic analyses prevail in the literature. The objective of our study is to assess the respective contributions of these two basic Aristotelian ontological couples to the study of animate beings. What are the scope and limitations of psychological hylomorphism? What role does the distinction between different levels of potentiality and actuality play in the DA and in the other treaties that deal with animate beings? What are the conceptual means that enable Aristotle to define the soul, to disentangle problems relative to soul-body relations and to bring together his psychological doctrine with his zoological research? Through an examination of these questions, the present study seeks to spell out how the so-called “first realization” fits in with the Aristotelian study of the soul and the animate.