, Volume 23, Issue 1, pp 101–112 | Cite as

Aristotle on a Puzzle about Logical Consequence: Necessity of Being vs. Necessity of Saying

  • Paolo Fait


In the Posterior Analytics (I 6, 75a18–27) Aristotle discusses a puzzle which endangers the possibility of inferring a non-necessary conclusion. His solution relies on the distinction between the necessity of the conclusion's being the case and the necessity of admitting the conclusion once one has admitted the premisses. The former is a factual necessity, whereas the latter is meant to be a normative or deontic necessity that is independent of the facts stated by the premisses and the conclusion. This paper maintains that Aristotle resorts to this distinction because he thinks that, as long as it is conceived as a factual relation, logical consequence cannot exist independently of the facts expressed by the premisses and the conclusion. As a corollary, the necessity of such a consequence relation always requires the necessity of these facts. Aristotle holds this factual conception of logical consequence responsible for the puzzle, since it cannot account for valid syllogisms with contingent or false premisses. The alternative conception of necessity is then introduced by him in order to make good this deficiency. The distinction between the necessity of being and the necessity of saying was revived by the Oxford logician E. W. B. Joseph, and taken over by Frank Ramsey in his seminal Truth and Probability, but has not received attention from recent interpreters of Aristotle's logic. This paper, however, argues that, in spite of its intrinsic interest, the distinction bore no significant fruit in Aristotle's logical doctrine.


Logical Consequence False Premiss Full Belief Partial Belief Present Occasion 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Barnes, J.: 1994, Aristotle: Posterior Analytics, Translated with a Commentary by J. Barnes, 2nd ed., Oxford: Oxford University Press.Google Scholar
  2. Boger, G.: 1993, 'The Logical Sense of Paradoxon in Aristotle's Sophistical Refutations', Ancient Philosophy 13, 55–78.Google Scholar
  3. Bonitz, H.: 1870, Index Aristotelicus, in Aristotelis Opera, edidit Academia Regia Borussica, vol. V, Berlin: Reimer.Google Scholar
  4. Brandom, R.: 1994, Making it Explicit: Reasoning, Representing, and Discursive Commitment, Cambridge (Mass.) & London: Harvard University Press.Google Scholar
  5. Cavini, W.: 1989, 'Modalità dialettiche nei Topici di Aristotele', in G. Corsi et al. (eds.), Le Teorie delle Modalità, Bologna: CLUEB, pp. 15–46.Google Scholar
  6. Corcoran, J.: 1974, 'Aristotle's Natural Deduction System', in J. Corcoran (ed.), Ancient Logic and its Modern Interpretations, Proceedings of the Buffalo Symposium on Modernist Interpretations of Ancient Logic, 21 and 22 April, 1972, Dordrecht/Boston: Reidel, pp. 85–131.Google Scholar
  7. Crubellier, M. and Pellegrin, P.: 2002, Aristote: Le philosophe et les savoirs, Paris: Seuil.Google Scholar
  8. Detel, W.: 1993, Aristoteles: Analytica posteriora, übersetzt und erläutert von W. Detel (Aristoteles, Werke in deutscher Ñbersetzung, begründet von E. Grumach, hrsg. von H. Flashar, Bd. 3, Teil II), 2 Teilbände, Berlin: Akademie Verlag.Google Scholar
  9. Fait, P.: 1996, 'Il linguaggio e l'abaco (Aristotele Soph. El. 1, 165a6–17)', in M. Serena Funghi (ed.), O?OI??IZHΣIOΣ: Le vie della ricerca, Studi in onore di Francesco Adorno, Firenze: Olschki, pp. 181–190.Google Scholar
  10. Fine, G.: 1984, 'Truth and Necessity in De Interpretatione 9', History of Philosophy Quarterly 1, 24–47.Google Scholar
  11. Geach, P. T.: 1972, Logic Matters, Oxford: Blackwell.Google Scholar
  12. Grattan-Guinness, I.: 1985–86, 'Russell's Logicism versus Oxbridge Logics, 1890–1925', Russell 5, 101–131.Google Scholar
  13. Joseph, H. W. B.: 1910, 'The Enumerative Universal Proposition and the First Figure of the Syllogism', Mind 19 (N. S.), 544–546.CrossRefGoogle Scholar
  14. Joseph, H. W. B.: 1916, An Introduction to Logic, 2nd ed., Oxford: Oxford University Press.Google Scholar
  15. Łukasiewicz, J.: 1957, Aristotle's Syllogistic from the Standpoint of Modern Formal Logic (1951), 2nd ed. enlarged, Oxford: Oxford University Press.Google Scholar
  16. Mignucci, M.: 1975, L'argomentazione dimostrativa in Aristotele: Commento agli Analitici Secondi, Padova: Antenore.Google Scholar
  17. Mignucci, M.: 2002, 'Syllogism and Deduction in Aristotle's Logic', in M. Canto-Sperber and P. Pellegrin (eds.), Le style de la pensée, Recueil de textes en hommage à Jacques Brunschwig, Paris: Les Belles Lettres, pp. 244–266.Google Scholar
  18. Pacius, I.: 1597, In Porphyrii Isagogen et Aristotelis Organum Commentarius Analyticus, Frankfurt: Wechel.Google Scholar
  19. Patzig, G.: 1968, Aristotle's Theory of the Syllogism, Dordrecht: Reidel (first published in German in 1959).Google Scholar
  20. Quine, W. V. O.: 1982, Methods of Logic, 4th ed., Cambridge (Mass.): Harvard University Press.Google Scholar
  21. Ramsey, F. P.: 1931, The Foundations of Mathematics and Other Logical Essays, ed. by R. B. Braithwaite, London: Routledge and Kegan Paul.Google Scholar
  22. Ramsey, F. P.: 1990, Philosophical Papers, ed. by D. H. Mellor, Cambridge: Cambridge University Press.Google Scholar
  23. Ramsey, F. P.: 1991, Notes on Philosophy, Probability and Mathematics, ed. by M. C. Galavotti, Napoli: Bibliopolis.Google Scholar
  24. Ross, W. D.: 1949, Aristotle's Prior and Posterior Analytics, A Revised Text with an Introduction and Commentary, Oxford: Oxford University Press.Google Scholar
  25. Sanford, D. H.: 1989, If P, then Q: Conditionals and the Foundations of Reasoning, London: Routledge.Google Scholar
  26. Searle, J.: 1969, Speech Acts, Cambridge: Cambridge University Press.Google Scholar
  27. Smiley, T. J.: 1973, 'What is a Syllogism?', Journal of Philosophical Logic 2, 136–154.CrossRefGoogle Scholar
  28. Smith, R.: 1997, Aristotle: Topics Books I and VIII, Translated with a Commentary by R. Smith, Oxford: Oxford University Press.Google Scholar
  29. Stalnaker, R. C.: 1981, 'Probability and Conditionals', in W. L. Harper et al. (eds.), Ifs, Dordrecht: Reidel, pp. 107–128.Google Scholar
  30. Striker, G.: 1998, 'Aristotle and the Uses of Logic', in J. Gentzler (ed.), Method in Ancient Philosophy, Oxford: Oxford University Press, pp. 209–226.Google Scholar
  31. Weidemann, H.: 1997, 'Aristoteles über Schlüsse aus falschen Prämissen: Zu Günther Patzigs Interpretation von Anal. pr. II 4, 57a36–b17', Archiv für Geschichte der Philosophie 79, 202–211.CrossRefGoogle Scholar
  32. Yrjönsuuri, M.: 1993, 'Aristotle's Topics and Medieval Obligational Disputations', Synthese 96, 59–82.CrossRefGoogle Scholar
  33. Yrjönsuuri, M.: 2001, 'Duties, Rules and Interpretations in Obligational Disputations', in M. Yrjönsuuri (ed.), Medieval Formal Logic, Dordrecht: Kluwer, pp. 59–82.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Paolo Fait

There are no affiliations available

Personalised recommendations