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Perelman's Interpretation of Reverse Probability Arguments as a Dialectical Mise en Abyme

2010; Penn State University Press; Volume: 43; Issue: 4 Linguagem: Inglês

10.1353/par.2010.0005

1527-2079

Manfred Kraus,

Classical Philosophy and Thought

Perelman's Interpretation of Reverse Probability Arguments as a Dialectical Mise en Abyme Manfred Kraus Introduction Imagine the following situation: an act of violent assault has been committed. And there are only two possible suspects, of which one is a small and weak man and the other a big and strong man. The weak man will plead that he is not strong enough and therefore not likely to have committed the crime, which seems reasonable straight away. But there will also be a loophole for the strong man, as Aristotle tells us, who reports exactly that story in book 2, chapter 24, of his Rhetoric. And he also has a name to assign to the inventor of that kind of argument (1402a17–20): The Art of Corax is composed of this topic. For if a man is not likely to be guilty of what he is accused of, for instance if, being weak, he is accused of assault and battery, his defence will be that the crime is not probable [eikós]; but if he is likely to be guilty, for instance, if he is strong, it may be argued again that the crime is not probable [eikós], for the very reason that it was bound to appear probable [eikós]. (Aristotle 1926, 335, translation modified). [End Page 362] Plato refers to the same example, though with slight differences, in the Phaedrus (273b–c), where he ascribes it to Tisias. In fact, the invention of such arguments by probability (eikós) has always been associated with the legendary founders of rhetoric, the Sicilians Corax and Tisias (see Hinks 1940, 63–66; Kuebler 1944, 15; Kennedy 1963, 26–51; Goebel 1989, 41–42; Gagarin 2002, 29), and their unscrupulous exploitation with sophists such as Protagoras and Gorgias (Aristotle, Rhetoric 1402a25; Plato, Phaedrus 267a). For our present purpose, we may confine our attention to Aristotle's version, since only this version contains the additional twist of the strong man's argument, and we may be confident—with Michael Gagarin—that "Aristotle's version is closer to Tisias' original version than Plato's" (Gagarin 2007, 33; see also 1994, 51). It matters little whether we ascribe it to Corax or Tisias. Tisias is regarded as Corax's student and may have recorded his master's teachings. But it has also been suggested that they may have been one and the same person, Corax ("Crow") being a nickname for Tisias (Cole 1991). The argument of the strong man, which wittily turns the tables on the simple argument from probability as used by the weak man, has been aptly dubbed the "reverse eikós-argument" or "reverse-probability argument" by Michael Gagarin (1990, 30; 1994, 51; 1997, 14; 2002, 112–14; 2007, 25). Yet, in no more than two pages in §96 of their New Rhetoric—as only very few scholars have ever noticed—Chaïm Perelman and Lucie Olbrechts-Tyteca offer an intriguing expanded account of this "reverse probability argument" (1969, 458–59), which is the subject of the following analysis. I first give a brief account of the background and operating mode of ancient probability arguments and of the particular variant of reverse probability that the strong man's argument represents and then analyze Perelman and Olbrechts-Tyteca's formulation, which I try to interpret as an instance of a dialectical application of the technique of mise en abyme and as a quasi-logical counterpart to logical paradoxes such as the Cretan liar and Russell's paradox. Probability and Reverse Probability Simple Probability Arguments In the fifth and fourth centuries BCE in particular, arguments from probability played a considerable role in Greek oratorical practice. Not only sophists such as Gorgias (Kuebler 1944, 26–36; Anastassiou 1981; [End Page 363] Spatharas 2001, 394–98) but also orators such as Antiphon, Lysias, Isocrates, and others made ample use of them (Kuebler 1944, 36–61; Synodinou 1981, 118–28; Gagarin 1989, 47–56; 1990, 29–31; 2002, 112–18, 153–54). In view of their importance in early rhetoric and oratory, the concept of eikós has been subjected to closer scrutiny in a significant number of recent studies (Kuebler 1944; Turrini 1977, 1979; Synodinou...