Document Type : Scientific-research

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Abstract

The Stoics believed that valid arguments are reduced to “undemonstrated’s’’ through “thema’s”. This interpretation, implied by ancient authors, considers Stoic logic as an axiomatic system with argumental rules. On the basis of this view on Stoic logic, undemonstrated’s are used as axioms and Themas as transmission rules. Yet, SextusEmpiricus in his book, Against the Logicians, introduced two examples of Stoic reduction of valid arguments to undemonstrated’s in which he used undemonstrated’s as sentential rules. In this approach, undemonstrated’s are used as inference rules and Themas don’t play any different reasonable role than undemonstrated’ss; on the other words, undemonstrated’s and Themas are used as inference rules. Mates and Bochenski didn’t attention to this conflict and analyzed these two examples like Empiricus. This paper brings up this conflict and suggests two solutions for it. Based on first solution, Stoic logic has two various surfaces and in each surface, it includes one of argumental or sentential rules; Therefore argumental rules and sentential rules can be used simultaneously. In second solution, based on the historical development of Stoic logic, two mentioned interpretations are attributed to Stoics in different historical periods.

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Bobzien, Susane (1996), “Stoic Syllogistic”, C. C. W. Taylor (ed.), Oxford Studies in Ancient Philosophy, Clarendon Press, Oxford.
Bocheński, I. M (1951), Ancient Formal Logic, North-Holland Publishing Company, Amsterdam.
Corcoran, John (1974), “Remarks on Stoic Deduction”, in Ancient Logic and Modern Interpretations, ed. John Corcoran, Dordrecht-Holland, D. Reidel Publishing Company.
Empiricus, Sextus (1976), Outline of Pyrrhonism, Trans. Rev. R. G. Bury (ed.) G. P. Goold, The Loeb Classical Library, Great Britain.
Empiricus, Sextus (2005), Against the Logicians, Trans. Richard Bett, Cambridge University Press, New York.
Empiricus, Sextus (2007), Outline of Sceptiticism, Trans. Julia Annas and Jonathan Barnes, Cambridge University Press, New York.
Gould, Josiah (1974), “Deduction in Stoic Logic”, in Ancient Logic and Modern Interpretations, ed. John Corcoran, D. Reidel Publishing Company, Dordrecht-Holland.
Laertius, Diogenes (1925), Lives of Eminent Philosophers, Trans. R.D Hicks, Vol. 2, The Loeb Classical Library, Great Britain.
Mates, Benson (1961), Stoic Logic, University of California Press: Berkeley and Los Angeles.
Milne, Peter (1995), “On the Completeness of Non-Philonian Stoic Logic”, History and Philosophy of Logic, vol. 16, No. 1, p: 39-64.
Mueller, Ian, (1979), “The Completeness of Stoic Propositional Logic”, Notre Dame Journal of Formal Logic, vol. 20, No. 1, p: 201-215.
Nasieniewski, Marek, (1998), “Is Stoic Logic Classical”, Logic and Logical            Philosophy, vol. 6, p: 55-61.