View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by NORA - Norwegian Open Research Archives THE STRUCTURE OF THE EXPERT- ANALOGY IN PLATO & ARISTOTLE BY PETTER SANDSTAD THESIS PRESENTED FOR THE DEGREE OF MASTER OF PHILOSOPHY SUPERVISED BY PROFESSOR ØYVIND RABBÅS DEPARTMENT OF PHILOSOPHY, CLASSICS, HISTORY OF ART AND IDEAS (IFIKK) UNIVERSITY OF OSLO SPRING 2012 II © Petter Sandstad 2012 The Structure of the Expert-Analogy in Plato & Aristotle By Petter Sandstad http://www.duo.uio.no/ Print: Reprosentralen, The University of Oslo III IV Abstract The expert (technē) analogy often plays an essential role in the arguments of Xenophon, Plato and Aristotle, and this type of argument can be traced back to Socrates. Yet there has been remarkably little work done on the argument itself. Vlastos, and to a lesser degree Robinson, interprets the majority of expert-analogies as intuitive inductions, where the conclusion is built into the concept of an expert and thus it is not an actual inference. On the other side McPherran, and to a lesser degree Santas, interprets them as probable inductions, i.e. an inference based on an insufficient number of cases or an insufficient number of similar attributes between the analogous cases, yielding a probable inference. This thesis tries to defend a third alternative, where the expert-analogy is understood as an inference from one species to another species, the inference being valid as there is a common genus to which the attribute inferred belongs per se. Thus the analogy is interpreted to have a valid deductive structure. It is claimed that a similar analogical structure can be found in other types of proofs, e.g. the homological proof found in evolutionary biology. It is further argued that this structure can be found in Aristotle’s discussion of the argument by example (paradeigma), and further that a justification can be found in Aristotle’s four-part division of identity into that of quantity, species, genus and analogy – and it is claimed that the expert-analogy is in fact based on an identity in genus. Indications can also be found in Plato, but these were not developed further by him. And in addition, the Aristotelian principle that a proof should be at its most generic level further justifies the proposed structure of the expert-analogy. Finally this structure is used in the discussion of several controversial cases of the expert-analogy, hopefully showing that the proposed structure is applicable to the various cases and allows for an increased understanding of them. V Acknowledgements First and foremost I want to acknowledge the many helpful comments and recommendations given to me by my supervisor for the thesis, Øivind Rabbås. Although I did not solicit your comments as often as I might and perhaps should have, the help I was given proved very advantageous. I want to thank Jens Ådne Rekkedal Haga for our good discussions, and especially for making me aware of the concept of homology as used in biology. The Department of Philosophy, Classics, History of Art and Ideas at the University of Oslo deserves my gratitude for the financial contribution that allowed me to present a paper to the 2010 meeting of the History of Economics Society at Syracuse University. Throughout my time as a student I have received much support from my family, thus making my life as a student more comfortable than it otherwise would have been, of which I am very grateful. Especially worth mentioning is the financial support that I received in connection to a workshop on discovery in the social sciences held at the University of Leuven, thus ensuring that I could present my paper. Gratitude also belongs to the taxpayers of Norway, for the grant and loan given during my studies, and for financing my alma mater. VI Preface The following dissertation should be of interest both to those already well acquainted with parts or all of the philosophical problems discussed, but also to novices on the current subject. To draw an analogy, Isocrates in his Against the Sophists 14-151 separates those of his students with the natural ability to become excellent speakers from those of an inferior nature. Both of these types of students can benefit from education in rhetoric, and should thus become students of Isocrates. Just the same, both of my type of readers can benefit from reading this dissertation, though the reader who is already well acquainted with the issue will understand the dissertation better. But both types should read it. All abbreviations of ancient authors and texts where available are from the list of abbreviations in Liddell & Scott. All translations of Plato are from the Complete Works edited by John M. Cooper, unless otherwise indicated. All translations of Aristotle are from the Complete Works edited by Jonathan Barnes, unless otherwise indicated. Square brackets within quotations indicate my own additions. It has been my general policy to translate Greek words, rather than simply using the Greek words by themselves. Where necessary for clarification I have added the Greek original. The reason for this is that by giving a translation I convey the additional information to the reader of how I think the word should be translated, and thus which connotations one should have to the word. 1 Vide Roochnik 1996: 76 ff. for a translation and discussion of this passage. VII VIII Table of Contents I Introduction ................................................................................................................................1 I. 1 Particulars and universals, genus and differentia ..................................................................3 I. 2 The history of the concept of an expert, from presocratic thought to Aristotle.......................5 II Previous commentators on the structure of the expert-analogy ...................................................8 III Biological homology ................................................................................................................ 22 IV An interpretation of Socratic analogies ..................................................................................... 25 V The theoretical basis for the expert-analogies ............................................................................ 27 V. 1 Plato’s discussion of analogies ........................................................................................... 27 V.2 Aristotle’s discussion of analogies ..................................................................................... 32 V. 2. 1 Aristotle’s concept of analogy (¢nalog…a)............................................................... 33 V. 2. 2 Metaphors (metafor£), images (e„kèn) and likenesses (ÐmoiÒthtej) ........................ 38 V. 2. 3 Paradigm (par£deigma) and induction (™p£gwgh) ..................................................... 44 V. 2. 4 Identity by genus & identity by analogy ................................................................. 53 V. 3 Concluding remarks on the justification of the expert-analogy ........................................... 61 VI Discussion on a few cases of expert-analogies .......................................................................... 65 VI. 1 Plato’s analogy of the captain and the politician in R. VI 488a-489c .............................. 65 VI. 2 Medicine and gymnastics as care for the body, philosophy as the care of the soul .......... 67 VI. 3 The expert-analogy in the Nicomachean Ethics, in particular the function-argument ...... 73 VII Conclusion ............................................................................................................................ 83 Bibliography: .................................................................................................................................... 85 IX X I Introduction There is a type of argument that is frequent in Plato’s dialogues, as well as in the Socratic writings of Xenophon and Aristotle (among other works the Nicomachean Ethics). In fact, it is used so frequent that both Plato and Xenophon refer to this type of argument as tired and worn out. “He’s always going on about pack asses, or blacksmiths, or cobblers, or tanners; he’s always making the same tired old points in the same tired old words [...] But [...] you’ll realize that no other arguments make any sense.” (Smp. 221e-222a) “By the gods! You simply don’t let up on your continual talk of shoemakers and cleaners, cooks and doctors, as if our discussion were about them!” (Grg. 491a) “[...] you will have to avoid your favourite topic,-- the cobblers, builders and metal workers; for it is already worn to rags by you in my opinion.” (Mem. I.II.37) Analogy is extremely frequent in the dialogues of Plato. ‘As this, so that’ is his refrain [...] It disappears to some extent in the later work; but the early and middle dialogues are full of it.” (Robinson 1953: 205) And again, “a very large number of the Platonic analogies, perhaps more than half, contain the notion of techne-episteme, which is in English the tetrad knowledge-science-art-technics.” (Robinson 1953: 206) Briefly put, the expert-analogy is the paradigmatic case of an analogy for Plato, and is so frequently used that Plato (as well as Xenophon) allows himself to be ironic and make jokes about it. Yet remarkably few have discussed the logical structure of the expert-analogies. In this paper I will present an interpretation of how these expert-analogies work, and assess their logical validity. Following Robinson,