|1.||(Logic) Characterizing that kind of reasoning which derives propositions from the observation of facts, or by generalizations from facts arrives at principles and definitions, or infers causes from effects. This is the reverse of a priori reasoning.|
|2.||(Philos.) Applied to knowledge which is based upon or derived from facts through induction or experiment; inductive or empirical.|
|Adj.||1.||a posteriori - involving reasoning from facts or particulars to general principals or from effects to causes; "a posteriori demonstration"|
a priori - involving deductive reasoning from a general principle to a necessary effect; not supported by fact; "an a priori judgment"
|2.||a posteriori - requiring evidence for validation or support|
|Adv.||1.||a posteriori - derived from observed facts|
a priori - derived by logic, without observed facts