syl·lo·gismˈsiləˌjizəm/nounan 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 ).deductive reasoning as distinct from induction."logic is rules or syllogism"