Table Of ContentTHE 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
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© 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
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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.
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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.
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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.
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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
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Description:and Aristotle, and this type of argument can be traced back to Socrates. further
argued that this structure can be found in Aristotle's discussion of the argument
