induction, in logic, method of reasoning from a part to a whole, from particulars to generals, or from the individual to the universal. As it applies to logic in systems of the 20th century, the term is obsolete. Traditionally, logicians distinguished between deductive logic (inference in which the conclusion follows necessarily from the premise, or drawing new propositions out of premises in which they lie latent) and inductive logic, but the problems earlier subsumed under induction are considered to be concerns of the methodology of the natural sciences, and logic is generally taken to mean deductive logic.