Definition of syllogism in US English:



  • 1An instance of a form of reasoning in which a conclusion is drawn (whether validly or not) from two given or assumed propositions (premises), each of which shares a term with the conclusion, and shares a common or middle term not present in the conclusion (e.g., all dogs are animals; all animals have four legs; therefore all dogs have four legs).

    • ‘Aristotle is also credited with coming up with the structure of syllogisms, or the formal determination of what can be inferred necessarily from certain statements.’
    • ‘Moreover, modern usage distinguishes between valid syllogisms (the conclusions of which follow from their premises) and invalid syllogisms (the conclusions of which do not follow from their premises).’
    • ‘From a formal point of view, a conclusion follows necessarily from the premises in a well-formed syllogism.’
    • ‘I wonder, has this censor never found in poetry a vision of truth more profound than can be told in syllogisms?’
    • ‘Based on these three elementary laws there were a number of syllogisms which were rules about correct inferences that could be made from given premises.’
    • ‘But all syllogisms require the premises to be true, and that is the fundamental failing of the brief.’
    • ‘To understand the history of ideas, we need to look not at syllogisms but at who wields power or at the subconscious mind.’
    • ‘In Hegel's syllogisms of the idea, objectivity attained rational form, while the concept acquired an explicit, material existence.’
    • ‘Mill first worked out his theory of terms, propositions, and the syllogism; he then set the book aside for five years.’
    • ‘In the latter, the syllogisms involved must have middle terms that are causes of the state of affairs which is to be demonstrated.’
    • ‘Aristotle was charged with preferring flimsy theories and sterile syllogisms to the solid, fertile facts.’
    • ‘No belief - reasoning correlation was found for syllogisms that had a neutral content.’
    • ‘From this developed a formal system of logic based on syllogisms which was acceptable to all parties in order to decide the outcome of such debates.’
    • ‘Speak not to me of syllogisms, you literal-minded dolts.’
    • ‘Kant notoriously claimed that logic had no need to go much beyond the Aristotelian syllogisms.’
    • ‘Both syllogisms have the same conclusion and the same logical form, but the syllogism immediately above has false premisses.’
    • ‘No sophistry and no syllogisms can conjure away this inevitable consequence of inflation.’
    • ‘But as with all syllogisms, the validity hinges on the major and minor premises.’
    • ‘They give reasons, they use syllogisms, they argue by suggesting counterexamples, they engage in all the hallmarks of reasoned argument.’
    • ‘My Lords, I think that these are instinctual sentences, not logical propositions or syllogisms, none the worse for that because we are not in the field of pure logic.’
    1. 1.1 Deductive reasoning as distinct from induction.
      ‘this schoool of epistemology is highly advanced in syllogism and logical reasoning’
      • ‘This is grand strategy by vacant syllogism and cliche.’
      • ‘Others think in terms of logical syllogism; for them the Cartesian system, when it can be applied, offers certainty.’
      • ‘This was, I felt, an argument that strained to yoke syllogism to its cause from love rather than good sense.’
      • ‘Dixwell throughout the review questions the validity of George's logic and his penchant for ‘droll syllogism.’’
      • ‘In my article in Prospect I recalled a breathtaking thought experiment dreamed up by the master of tendentious syllogism.’
      • ‘It was first formalized in Western philosophy by Aristotle, who described a simple variety of it known as syllogism.’
      • ‘Legal reasoning by analogy and syllogism was one aspect of the effort needed to fathom the law as revealed by God and his Prophet.’
      • ‘His ability to combine syllogism with sentiment is remarkable.’
      • ‘I don't rightly know, but I'll propose a possible counterexample - a 20 th-c. poet who often proceeded by syllogism at least as much as by coherence of feeling: Philip Larkin.’


Late Middle English: via Old French or Latin from Greek sullogismos, from sullogizesthai, from sun- ‘with’ + logizesthai ‘to reason’ (from logos ‘reasoning’).