Why are there no conditionals in aristotle's logic?

David Ebrey*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


Aristotle presents a formal logic in the Prior Analytics in which the premises and conclusions are never conditionals. In this paper I argue that he did not simply overlook conditionals, nor does their absence reflect a metaphysical prejudice on his part. Instead, he thinks that arguments with conditionals cannot be syllogisms because of the way he understands the explanatory requirement in the definition of a syllogism: The requirement that the conclusion follow because of the premises. The key passage is Prior Analytics I.32, 47a22-40, where Aristotle considers an argument with conditionals that we would consider valid, but which he denies is a syllogism. I argue that Aristotle thinks that to meet the explanatory requirement a syllogism must draw its conclusion through the way its terms are predicated of one another. Because arguments with conditionals do not, in general, draw their conclusions through predications, he did not include them in his logic.

Original languageEnglish (US)
Pages (from-to)185-205
Number of pages21
JournalJournal of the History of Philosophy
Issue number2
StatePublished - Apr 1 2015


  • Aristotle
  • Conditionals
  • Prior analytics
  • Syllogism from a hypothesis
  • Wholly hypothetical

ASJC Scopus subject areas

  • Philosophy


Dive into the research topics of 'Why are there no conditionals in aristotle's logic?'. Together they form a unique fingerprint.

Cite this