The current study examined the effects of cardiorespiratory fitness, identified with a continuous graded cycle ergometry, and aerobic exercise on cognitive functioning and entropy of the electroencephalogram (EEG) in 30 adolescents between the ages of 13 and 14 years. Higher and lower fit participants performed an executive function task after a bout of acute exercise and after rest while watching a film. EEG entropy, using the sample entropy measure, was repeatedly measured during the 1500ms post-stimulus interval to evaluate changes in (...) entropy over time. Analysis of the behavioural data for lower and higher fit groups revealed an interaction between fitness levels and acute physical exercise. Notably, lower fit, but not higher fit, participants had higher error rates for NoGo relative to Go trials in the rest condition, whereas in the acute exercise condition there were no differences in error rates between groups; higher fit participants also had significantly faster reaction times in the exercise condition in comparison with the rest condition. Analysis of EEG data revealed that higher fit participants demonstrated lower entropy post-stimulus than lower fit participants in the left frontal hemisphere, possibly indicating increased efficiency of early stage stimulus processing and more efficient allocation of cognitive resources to the task demands. The results suggest that EEG entropy is sensitive to stimulus processing demands and varies as a function of physical fitness levels, but not acute exercise. Physical fitness, in turn, may enhance cognition in adolescence by facilitating higher functionality of the attentional system in the context of lower levels of frontal EEG entropy. (shrink)

Plotinus : a detailed study of Plotinus' theories on matter and the soul , in relation to select passages from his treatise Against the Gnostics.

« La matière est-elle identique à l'altérilé ? » Plotin se pose cette question au commencement du dernier chapitre de son traité Sur la matière (Enn., II 4 [12] 16). « Plutôt non », répond-il. « Elle est en revanche identique à cette partie de l'altérité qui s'oppose aux êtres proprement dits. » En s'exprimant de la sorte, Plotin fait allusion à un passage du Sophiste (258 E 2-3). Son allusion suppose pourtant l'existence d'un texte qui n'est pas attesté dans (...) les manuscrits. Cette différence textuelle implique un changement fondamental de doctrine, dont les éditeurs modernes ne se sont pas avisés. (shrink)

Desde o século XVII, começaram as disputas. De um lado, as modernidades liberais. De outro, as modernidades alternativas. Entre as múltiplas tendências, um denominador comum - evitar como possível as tragédias provocadas pelos programas liberais de modernidade. No século XX, propostas - pela esquerda, a social-democracia, o socialismo soviético, os nacionais-estatismos; pela direita, os corporativismos, os fascismos, o nazismo. Este livro trata do intervalo dos projetos alternativos de modernidade em seus itinerários, contradições e impasses.

The origin of matter is one of the last and greatest unsolved mysteries bedevilling modern attempts at understanding the philosophy of the "Enneads." There are two stages in the production of Intellect and of soul. The One or Intellect produces an undifferentiated other, which becomes Intellect or soul by itself turning towards and looking towards the prior principle, with no possibility of the One's "turning towards" or "seeing" itself. But where does matter come from? To arrive at his conception of (...) matter, Plotinus has radically altered the definitions of non-being given by Plato and Aristotle in their refutation of Parmenides. Matter, for Plotinus, is a non-being opposed, not to "the being of each thing", as in Plato's "Sophist," but to all "the beings properly so-called", i.e. to all the forms. It is then further identified with Aristotle's definition of non-being as privation, with the crucial difference that privation, for Plotinus, is made a permanent substratum of change. This re-formulation of ideas from the "Sophist" and the "Physics" proves unmistakably that it is matter which is generated when soul produces a "non-being" which is also a "total lack of definition". The production of matter by soul does not, however, follow the model of the production of Intellect from the One or of soul from Intellect. Since matter is lifeless, it cannot turn towards its source. Soul therefore has to be herself directly responsible both for the production of matter and for the covering of matter with form. Matter is therefore included among the products which stem ultimately from the One. But the origin and the nature of matter have to be understood as very different from the double process of emanation which lies at the origin of Intellect and of soul. (shrink)

Hitherto reconstructions of Empedocles' cosmic cycle have usually been offered as part of a larger work, a complete history of Presocratic thought, or a complete study of Empedocles. Consequently there has perhaps been a lack of thoroughness in collecting and sifting evidence that relates exclusively to the main features of the cosmic cycle.

Does the matter of the sensible world, for Plotinus as for Plato and Aristotle, exist without a cause of its existence? Long divided on the answer to that question, scholarly opinion now veers in favour of a derivation of matter from principles prior to matter, with disagreement limited to the details of the theory. What exactly is implied by the various passages of the Enneads where Plotinus writes of soul or physis in relation to `darkness' and `non-being', matter and form? (...) In the pages that follow, I argue that the soul's `making' of a `non-being' that by implication is matter, in Enn. III 9 [13] 3, is logically antecedent to the `making' of `visible form' ascribed to physis in Enn. III 8 [30] 2. A detailed study of the context and the syntax of the latter passage shows that, contrary to an interpretation put forward recently in this Journal, the two `makings' cannot be the same. (shrink)

A curious irony hangs over the two similes of the lantern and the clepsydra which Empedocles used to describe his theories of seeing and breathing. Similes were a feature of Empedocles' style, and it is clear that on these two in particular he has lavished considerable care. They have been preserved in their entirety, as almost the longest continuous quotations which Aristotle makes from any author. Despite such auspicious beginnings, these two similes have proved peculiarly resistant to modern attempts at (...) interpretation. The reason for this, I shall try to show, is that certain features in the two similes took on a spurious significance as a result of Plato's remodelling of Empedocles' theories. Difficulties of interpretation have been caused by trying to read back these innovations of Platonic theory into details of the similes that in their original context were fortuitous and inessential.In Plato vision occurs when fire leaves the eye and joins fire outside to form a single compacted body, along which movements from the visible object are communicated as sensations to the eye.According to Theophrastus, Empedocles explained vision as the result of effluences which are given off from objects and enter the appropriate pores of the eye. Dark effluences enter the watery pores of the eyes, and bright effluences enter the fiery pores of the eye. As I have tried to show in an earlier article, Empedocles distinguished good and bad vision, by day and by night, for eyes with a predominance of fire and for eyes with a predominance of water. Good vision results when the dark and light elements which enter the eye are equally balanced. Poor vision results either when there is too much fire in the eye, so that we are dazzled, or when there is too much water in the eye, so that our vision is dimmed. In the whole of his detailed and one would have thought exhaustive account, Theophrastus says nothing about fire leaving the eye as a factor in the act of vision. (shrink)

Abstract Plotinus did not set out to be obscure. Difficulties of interpretation arise partly from his style of writing, compressed, elliptical, allusive. The allusions, easily enough recognisable by those he was writing for, are often not recognised at all by the modern reader who no longer has at his fingertips the texts of Plato and Aristotle that Plotinus undoubtedly alludes to, but whose authors he has no need to name. So it is pre-eminently with his subtle use of earlier ideas (...) in tackling the difficult question of the nature of matter and its place in the scheme of emanation. The frequent references to matter as `non-being' and as `privation' can be understood only if they are seen as a radical adaptation of the paradoxical definition of a `form that is, of what is not' in Plato's Sophist (258 D 5-7) and as a deliberate correction of Aristotle's unsuccessful attempt at including female desire in an analysis of privation in the Physics (i 9, 192 a 22-25). Only when the debt to Plato and Aristotle has been recognised for what it is are we able to appreciate that matter defined as `non-being' is not therefore `non-existent', and that the `privation' that is matter is not a terminus a quo of change, but a permanent substrate of change. The adaptation and the daring syncretism lead to deliberate paradox in Plotinus' own definition of matter as both `so to speak a form of sorts' and `formless' (I 8 [51] 3). The seeming inconsistency is Plotinus' acknowledgment of the use he has made of earlier ideas when he writes of matter, so defined, as `made' by a lower manifestation of soul, and therefore as the last and the least of the products flowing from, but not created by, the One. (shrink)

Empedocles’ repeated description of his four “roots” or elements by the repetition of three seemingly simple words (αὐτά + ἐστίν + ταῦτα) has constantly defied explanation. If the verb is given a copulative function, the result appears to be a pointless tautology (“these things are themselves”). If it is given an existential value, the result is puzzlingly abstruse (“these things themselves are”). Translators therefore commonly opt for a loose paraphrase, where one word out of three is not translated at all (...) (αὐτά) and an adverb (“only”) is added, seemingly from nowhere (“only these things are”). The solution to the puzzle is to be found in Empedocles’ reaction to his older contemporary, Anaxagoras. Empedocles’ repeated description is a covert criticism of Anaxagoras’ curious claim that “in everything there is a part of everything”. (shrink)

I am sorry to have annoyed Dr Dicks by criticising two articles of his in one of my footnotes. I limit myself to the four specific points raised, in the hope that Dr Dicks may one day be kind enough to substantiate his more general criticisms.Pseudo-GalenFive separate doxographical sources attribute to Anaxagoras the statement that the sun is larger, or many times larger, than the Peloponnese. Galen, or pseudo-Galen, notes that Anaxagoras' sun is larger than the earth. I suggested that (...) this second formula, although it may not misrepresent the substance of Anaxagoras' theory, was ‘probably in Galen simply a random error, arising from the fact that the preceding sentence, on Anaximander, twice makes a comparison of sun and earth’. It is hard to know what motivates Dr Dicks to omit my reasoning and to stigmatise my conclusion as ‘curious’ and ‘eccentric’. (shrink)

Recent attempts at giving meaning to Empedocles’ enigmatic metaphor of a ‘pathway’ and ‘summits’ suffer from weaknesses logical no less than philological. Contrary theses do not have to be contradictory. Does Empedocles express a preference for ‘summits’ as opposed to a ‘pathway’, or for a ‘pathway’ as opposed to ‘summits’? Very possibly neither. The context in which the two verses are quoted points rather to a graceful peroration. However many ‘summits’ there may have been on the way, the traveller has (...) to complete his journey. However many the fascinating topics Cleombrotus has spoken of, he has to know how to bring his speech, his ‘path of words’, to a successful conclusion. (shrink)

Empedocles' fr. 24 is known only from its quotation by Plutarch. The words as quoted leave themselves open to divergent interpretations. The context in Plutarch nonetheless holds out some hope of being able to decide which of the divergent interpretations would have matched the use that Empedocles himself made of the two verses in his poem.

Aristotle and Theophrastus are the two major sources for our knowledge of the atomist theory of weight.In theDe generatione et corruptioneAristotle argues that one atom may be hotter than another and that therefore the atoms cannot be impassible, since an atom which is only slightly hot could not fail to be acted upon by an atom that was very much hotter. The premiss to the argument Aristotle derives in part from a comparison with weight. It would be ridiculous, he claims, (...) to suppose that hotness and coldness belong to the atoms, but that heaviness and lightness, hardness and softness do not belong to them. And in fact, he continues, Democritus does claim that each of the ‘indivisibles’ is βαρύτερον…κατὰ τὴν ὑπεροχήν. Aristotle has already supposed that one kind of atom, a round atom, may be accounted as hot. The use of the comparative for weight Aristotle now takes to justify the use of the comparative for heat : from this there follows the argument that the atoms cannot be impassible. (shrink)

Stobaeus records a placitum where Empedocles says that the world is destroyed by the domination in turn of Love and of Strife. The placitum makes perfectly good sense in the context of Empedocles' belief that Love and Strife produce, in turn, a non-cosmic state of total unity (Love) and of total separation (Strife). But for over two hundred years scholars have been unable to hear that simple message. Sturz (1805) emended the text so as to make it fit the non-cyclical (...) interpretation of Empedocles that he had taken over from the pages of Tiedemann (1791). When Diels included Stobaeus' text in his edition of Aetius, in the "Doxographi graeci" (1879), he failed to remove the emendation, although his own reconstruction of the chapter heading in Aetius made the emendation impossible. Twenty years later, Diels saw the light, and printed Stobaeus' placitum, unemended, in his "Poetarum philosophorum fragmenta" (1901) and in successive editions of his "Fragmente der Vorsokratiker" (from 1903 onwards). But Kranz resurrected the emendation in the "Nachträge" to his sixth edition of the "Fragmente der Vorsokratiker" (1951). The emended placitum is used again by Uvo Hölscher (1965) to support a non-cyclical interpretation of Empedocles and is repeated in the latest collection of the fragments and testimonia (Brad Inwood, 1992). Hölscher fails to appreciate that the text that he uses to support his reconstruction is merely Sturz's translation into Greek of the non-cyclical interpretation of Empedocles proposed by Tiedemann at the end of the eighteenth century. (shrink)

To unravel the intricacies of the last argument of the Phaedo for the immortality of the soul, the reader has to peel away successive presuppositions, his own, Plato's and not least the presupposition that Plato very skilfully portrays as being shared by Socrates and his friends.A first presupposition is the reader's own. According to our modern ways of thinking, a soul that is immortal, if there is such a thing, is a soul that lives forever. That presupposition is not shared (...) by Socrates and Cebes (Socrates' interlocutor in the final argument). A soul that survives separation from the body, once or a number of times, is held to have survived death and therefore to be immortal. But it does not follow that it will live forever. For a soul to live forever, it must be shown to be not only immortal, but imperishable. Only if the soul is both immortal and imperishable can the assembled company be sure that the Socrates who is talking to them now will still be living when, after sunset, he has drunk the hemlock and can talk to them no more.The modern reader who has divested himself of the presupposition that immortal and imperishable are mere synonyms, and therefore appreciates the need for an argument designed specifically to prove that the soul is imperishable and not merely immortal, has nonetheless to be aware of a second presupposition, a presupposition shared by Socrates and his friends which restricts the meaning that the modern reader might otherwise suppose to be conveyed by the word 'imperishable'. Both Socrates and Cebes, as portrayed in the Phaedo, take it for granted that the only time when the soul might perish is the moment of her separation from the body. Provided it can be shown that the soul will survive separation from the body, no matter how often the body is taken from her, the soul, so they are happy to assume, will have shown herself to be both immortal and imperishable.We do not have to suppose that this second presupposition is shared by the author of the dialogue. Plato's subtle but insistent restriction of the moment when the soul might be threatened with extinction to the moment of her separation from the body has been deliberately designed to alert the reader to a way of thinking which Socrates, Cebes and Echecrates all take for granted, but which Plato does not necessarily invite the reader of the dialogue to share.The restriction is nonetheless essential to the structure of the argument. It is because Socrates does not envisage a possible extinction of the soul at any moment other than the moment of separation from the body that he is able to present a soul that is essentially alive as immune to the death which separates soul from body, however often such a separation may occur, and as therefore (so he claims) not only immortal but imperishable.In presenting that argument, how far has Plato deliberately foregone any attempt to prove that the soul is imperishable subsequently to the moment of her separation from the body? Socrates argues that the soul is unaffected by the death of the body because she is essentially alive. He does not argue that she is immune to destruction or extinction because she is essentially existent. In the face of Plato's silence, in the Phaedo and elsewhere, the modern reader has to hold in abeyance a third and final presupposition, that only a being whose essence it is to exist can of its nature never not exist.To understand the dialogue is therefore no easy matter. The reader needs to distinguish Socrates as the mouthpiece of Plato from Plato as the author of the dialogue. At the same time the modern reader has to distinguish the Plato of history from a fictional Plato who shares our own ideas and our own preconceptions, including the concept of a being cuius essentia est esse. An intricate double task, which other modern readers of the dialogue have so far not even attempted. (shrink)

Soul springs from Intellect, Intellect springs from the One. But quite how does the sensible world arise? A pair of almost successive treatises points to the answer. A lower manifestation of soul `makes' or `gives birth to' what is variously described as `non-being', `utterly indefinite' and `utterly dark', before covering what she has made with form, specifically the form of `body', and before `entering rejoicing' into the object that, by its reception of form, has been made ready to receive her (...) and that, as the `dwelling place' of soul, will be none other than the visible cosmos. A pair of earlier, again almost successive treatises, spells out the implication. The matter of the sensible world, covered with at least a minimum of form, is described as a `corpse adorned'. The same object, but prior to its `adornment', prior therefore to its appearance as a `body' that is a `corpse', and prior to any `indwelling' of soul, is specifically said to be `non-being' and the `darkness of matter', a transparent allusion to the product of soul in the two later treatises. The soul's making of `darkness', so we may infer, is a making of `matter', the final act in the drama by which everything that exists, including the material substrate of the world we see and feel around us, stems ultimately from the One. (shrink)