Reasoning is a process, by which unknown truths are inferred from those, which are already known or admitted. The evidence, employed in reasoning, is deductive, and is distinguished into two kinds, which are, moral and demonstrative. Moral evidence is that species of proof, which is employed on subjects, directly or indirectly connected with moral conduct. Demonstrative evidence is that, by which
... [Show full abstract] we trace the relations, subsisting among things, in their nature immutable, like the subjects of geometry and arithmetick. On this distinction of deductive evidence is founded the most general division of reasoning, which is into moral or probable, and demonstrative. The principal differences in these modes of reasoning are the following: they differ in regard to their subjects; for if any proposition be demonstrated to be true, whatever can be offered, as proof, on the opposite side, must be mere fallacy; propositions, contrary to those established by moral evidence, are merely false, but those which are contrary to demonstrated propositions, are not only false, but likewise absurd; in demonstration there are no degrees; in every process of demonstrative reasoning, the proofs are framed into one coherent series, each part of which must have an intuitive agreement with that, which goes before, and with that, which follows it; and the obstacles, which occur in the practice of these two modes of reasoning, are of different kinds. It should also be remarked here, that the epithet, probable, as applied by logicians to the evidence of moral reasoning, has a technical meaning, altogether different from its usual signification. In logical discussions, it has a more comprehensive meaning, not only including every subordinate degree of moral evidence, but also the highest. (PsycINFO Database Record (c) 2012 APA, all rights reserved)