Deductive reasoning and the argument is “valid”, it is possible for the conclusion to be false (determined to be false with a counterexample or other means). Aristotle started documenting deductive reasoning in the 4th century BC. Deductive reasoning Deductive reasoning, also deductive logic, logical deduction is the process of reasoning from one or more statements (premises) to reach a logically certain conclusion. Deductive reasoning goes in the same direction as that of the conditionals, and 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
Logical consequence Dummett. The accounts discussed above all yield monotonic consequence relations, i.e. ones such that if formula_10 is a consequence of formula_12, then formula_10 is a consequence of any superset of formula_12. It is also possible to specify non-monotonic consequence relations to capture the idea that, e.g., 'Tweety can fly' is a logical consequence of but not of For more on this, see Non-monotonic inference relation. Logical consequence Logical consequence (also entailment) is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically "follows from" one or more statements. A valid logical argument