## ::Deductive reasoning

### ::concepts

Logic::argument False::premises Example::valid First::editor Logic::premise Angle::carrots**Deductive reasoning**, also **deductive logic**, **logical deduction** or, informally, **"top-down" logic**,<ref>Deduction & Induction, Research Methods Knowledge Base</ref> is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion.<ref>{{#invoke:citation/CS1|citation
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Deductive reasoning links premises with conclusions. If all premises are true, the terms are clear, and the rules of deductive logic are followed, then the conclusion reached is necessarily true.

Deductive reasoning (top-down logic) contrasts with inductive reasoning (bottom-up logic) in the following way: In deductive reasoning, a conclusion is reached reductively by applying general rules that hold over the entirety of a closed domain of discourse, narrowing the range under consideration until only the conclusion(s) is left. In inductive reasoning, the conclusion is reached by generalizing or extrapolating from, i.e., there is epistemic uncertainty. Note, however, that the inductive reasoning mentioned here is not the same as induction used in mathematical proofs – mathematical induction is actually a form of deductive reasoning.

**Deductive reasoning sections**

Intro Simple example Law of detachment Law of Syllogism Law of contrapositive Validity and soundness History Education See also References Further reading External links

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