Abductive Reasoning

American philosopher and logician Charles Sanders Peirce formulated and advanced abductive reasoning beginning in the latter half of the 19th century. Peirce discovered a third kind of reasoning—different from deduction and induction—which he called abduction or retroduction, identifying it with the logic of scientific discovery. According to Peirce, "The surprising fact, C, is observed. But if A were true, C would be a matter of course. Hence, there is reason to suspect that A is true." He made two important claims: abduction was the only ampliative reasoning (extending knowledge beyond premises) and was essential to science. Peirce indicated that abduction is driven by "economy in research"—the expected productivity of hypotheses prior to verification.