Opposing the tendency to read Thucydides as a strong realist, committed to a theory of behaviour that assumes rationality as expected utility maximization, Ned Lebow and Clifford Orwin (among others) emphasize Thucydides’ attentiveness to deviations from rationality by individuals and states. This paper argues that Thucydides grasped the principles underlying contemporary prospect theory, which explains why people over-weight small probabilities and under-weight near certain ones. Thucydides offers salient examples of excessive risk-aversion in the face of probable gains and excessive risk-seeking by decision-makers faced with high probability losses. Thucydides suggests that in a democracy, leaders’ rhetoric can limit or exacerbate the political effects of bias in risk assessment.
Lebow, ‘Thucydides the Constructivist’, p. 557; J.S. Levy, ‘An Introduction to Prospect Theory’, Political Psychology, 13 (1992): pp. 171-86; J.S. Levy, ‘Loss Aversion, Framing and Bargaining: The Implications of Prospect Theory for International Conflict’, International Political Science Review, 17 (1996), pp. 179-95; A. Tversky and D. Kahneman, ‘Advances in Prospect Theory: Cumulative Representation of Uncertainty’, Journal of Risk and Uncertainty, 5 (1992), pp. 297-323.
We differ with Orwin, The Humanity of Thucydides, pp. 32-37and Appendix 2, in how to interpret the key phrase. Orwin translates prophasis as ‘allegation’ but we do not understand how something can be at once ‘alleged’ and yet ‘least expressed’ (aphanestatên logôi); it seems to us that an allegation is, by definition, expressed rather than hidden, whereas causes, including the truest, are sometimes most obscure. Moreover, at 1.88.1 (with Orwin p. 42), Thucydides in propria persona says that Spartan fear of Athens was their actual (not just declared) motive for declaring war.
Edmunds, Chance and Intelligence, pp. 7-22, 205-214; Desmond, ‘Lessons of Fear’, pp. 371-3. We cannot discuss Edmunds’ comprehensive study on chance and planning in this paper, though it is important to note that Edmunds concludes that Thucydides, though close to Pericles, ultimately thought that chance can be overcome by rational planning only with the hindsight of a historian. Whether or not it is possible for a statesman or historian to completely eliminate the influence of chance, the main point remains: Thucydides thought it worthwhile for statesmen and leaders to invest in strategic planning in order to overcome uncertainties and Pericles is Thucydides’ prime example of the benefits of this effort.