This week I have been attending the annual meetings of the American Philosophical Association (Eastern Division) in
To begin with, of course, there is the fundamental distinction between deductive and inductive reasoning. Deductive reasoning is the type that is used largely in mathematics and formal logic, though it has a place in both science and everyday discourse. Deduction is the process by which one derives conclusions from a set of premises. If the formal structure of the deductive argument is correct, and the premises are true, the conclusion is guaranteed to be true. Of course, often enough some of the premises are questionable, or are derived from the other kind of logical reasoning (see below), which does not guarantee truth.
There are three fundamental types of deductive reasoning: