What really characterizes explananda: Prior Analytics I.30

In Prior Analytics I.30, Aristotle seems too much optmistic about finding out the principles of sciences. For he seems to say that, if our empirical collection of facts in a given domain is exhaustive or sufficient, it will be easy for us to find out the explanatory principles in the domain. However, there is a distance between collecting facts and finding out the explanatory principles in a given domain. In this paper, I discuss how the key expression in the sentence at 46a25 should be interpreted: “the true characteristics of things” (“τῶν ἀληθῶς ὑπαρχόντων τοῖς πράγμασιν”). I argue that, on a more accurate interpretation of the expression, Aristotle’s point would cease to look like a piece of naïve or even silly optimism

Aristotle’s Definition of Scientific Knowledge

In Posterior Analytics 71b9 12, we find Aristotle’s definition of scientific knowledge. The definiens is taken to have only two informative parts: scientific knowledge must be knowledge of the cause and its object must be necessary. However, there is also a contrast between the definiendum and a sophistic way of knowing, which is marked by the expression “kata sumbebekos”. Not much attention has been paid to this contrast. In this paper, I discuss Aristotle’s definition paying due attention to this contrast and to the way it interacts with the two conditions presented in the definiens. I claim that the “necessity” condition ammounts to explanatory appropriateness of the cause

Causality and Coextensiveness in Aristotle's Posterior Analytics 1.13

I discuss an important feature of the notion of cause in Post. An. 1. 13, 78b13–28, which has been either neglected or misunderstood. Some have treated it as if Aristotle were introducing a false principle about explanation; others have understood the point in terms of coextensiveness of cause and effect. However, none offers a full exegesis of Aristotle's tangled argument or accounts for all of the text's peculiarities. My aim is to disentangle Aristotle's steps to show that he is arguing in favour of a logical requirement for a middle term's being the appropriate cause of its explanandum. Coextensiveness between the middle term and the attribute it explains is advanced as a sine qua non condition of a middle term's being an appropriate or primary cause. This condition is not restricted either to negative causes or to middle terms in second‐figure syllogisms, but ranges over all primary causes qua primary

Phronesis e Virtude do Caráter em Aristóteles: comentários a Ética a Nicômaco VI

These are commentaries to the translation into Portuguese of Nicomachean Ethics VI, found in the same volume of Dissertatio

Initiatory Silence

Initiatory symbology collects various forms of symbols: those that belong to an ancient tradition and that present themselves as a normalization of the past in a modernized key; those that derive from a pact between the members of the initiatory community and that guarantee the unity of the group, which are synchronized within the group itself; those that have the sense of projection to overcome the gnoseological limits of the group and its members, are traditional but through their character of semantic multiplicity offer new gnoseological opportunities. Silence is not part of the first category, because not all ancient or traditional initiatory groups used it ritually or considered it as a symbol and therefore could not have a normative function susceptible to modernization. It can be a crucial moment of the second when it is ritualized in the different phases of learning on the basis of an agreement connected to the creation of the ritual and forming itself as one of the synchronic fulcrums of the group, ensuring its unity. It can also belong to the third case when it takes on a traditional guise but having its own multidimensional semantics, in the communion of saying and silent pulses of new opportunities for initiatory growth. Silence in the initiatory context is a specific linguistic form that characterizes the entire path of the initiates. Within the group, they elaborate the syntax of silence, the morphology of tacitly expressed symbols, without fully explaining their meanings. Each symbol, or sign in the semiotic sense, has different meanings for the different phases of the initiation process. Each one belongs to a different type of relationship with what it refers to: it has a relationship of "similarity" such as the design of a team and compass that illustrates operational objects, of "proximity" when it manifests the operation of measuring and relating the relationships for which the object is intended, of "concordance" if it refers to the object within the knowledge of an architectural rule. The symbol as a special form of sign manifests itself (first phase of learning), as in the example, in iconographic-descriptive mode containing a meaning "dictated". It is an initiatory dictatio to be kept in silence in front of the essoteric world, of which the initiating is still permeated, the symbolism must be evoked without making explicit its intimate meanings, it is described but not fully exposed. It is the evocative, indeterminate and silent value that must stimulate the initiating in the search for meanings. The indetermination of silence destructures the essoteric, its thought its categories, criteria and values, leads to the desert of essoteric meanings as a way to the ontology of initiatory language. It is a stage of waiting, of referral to another world. We suspect meanings that in the next phase begin to manifest themselves in a more precise dictatio, a functional dictamen to represent the concept of measurement in its multiple meanings where the measure is assumed as symbolic-conceptual abstraction. Continuing, the sign in the form of an object strips itself of any factual and existential reference, of the communication of an abstraction or conceptual ideation and unmasks itself in its being an initiatory "rule". It is assumed, therefore, that initiatory improvement passes through the understanding of the signs, an understanding that is increasingly deeper and more comprehensive and that is autonomous and independent of the signs of the exoteric world. With regard to the symbolic-initiatic language, learning, from the apprenticeship phase to the following phases, focuses on the study of the formal relationships of symbols within initiatory gnoseology, on the meanings inherent in symbols and on their relationship with the initiatory community

Decay of geodesic acoustic modes due to the combined action of phase mixing and Landau damping

Geodesic acoustic modes (GAMs) are oscillations of the electric field whose importance in tokamak plasmas is due to their role in the regulation of turbulence. The linear collisionless damping of GAMs is investigated here by means of analytical theory and numerical simulations with the global gyrokinetic particle-in-cell code ORB5. The combined effect of the phase mixing and Landau damping is found to quickly redistribute the GAM energy in phase-space, due to the synergy of the finite orbit width of the passing ions and the cascade in wave number given by the phase mixing. When plasma parameters characteristic of realistic tokamak profiles are considered, the GAM decay time is found to be an order of magnitude lower than the decay due to the Landau damping alone, and in some cases of the same order of magnitude of the characteristic GAM drive time due to the nonlinear interaction with an ITG mode. In particular, the radial mode structure evolution in time is investigated here and reproduced quantitatively by means of a dedicated initial value code and diagnostics.Comment: Submitted to Phys. Plasma

Aristóteles, Metafísica Livros I, II e III

Translation of Aristotle's Metaphysics I-III into Portuguese, with a few notes and introduction. The translation, which was made at 2007, is preliminary and its publication was intended to provide a didactic tool for courses as well as a provisional resource in research seminars. It needs some revision. I am currently working (slowly...) on the revision of the translation and a new revised one will surely appear at some point

Aristóteles e a necessidade do conhecimento científico

I discuss the exact meaning of the thesis according to which the object of scientific knowledge is necessary. The thesis is expressed by Aristotle in the Posterior Analytics, in his definition of scientific knowledge. The traditional interpretation understands this definition as depending on two parallel and independent requirements, the causality requirement and the necessity requirement. Against this interpretation, I try to show, through the examination of several passages that refer to the definition of scientific knowledge, that the necessity requirement specifies more exactly the causality requirement: what cannot be otherwise is the explanatory relation between the explanandum and the cause by which it is what it is

Demonstração, silogismo e causalidade

This chapter argues in favour of three interrelated points. First, I argue that demonstration (as expression of scientific knowledge) is fundamentally defined as knowledge of the appropriate cause for a given explanandum: to have scientific knowledge of the explanandum is to explain it through its fully appropriate cause. Secondly, I stress that Aristotle’s notion of cause has a “triadic” structure, which fundamentally depends on the predicative formulation (or “regimentation”) of the explanandum. Thirdly, I argue that what has motivated Aristotle to choose the syllogism as a demonstrative tool was precisely the fact that syllogisms are apt to express causal relations in their triadic structure. Instead of complaining against Aristotle’s preference for the syllogisms as demonstrative tools, I argue that Aristotle was fully aware of the advantages of regimenting the explanandum into a predication. One of these advantages is to abandon a purely extensional standpoint and to highlight the importance of the notion of relevancy in explanation