From Clear Thinking by R W Jepson
DEDUCTION means using a general rule by applying it to particular cases. It is thus the reverse process to Induction; Induction moves from a number of particulars to a generalisation, Deduction from the generalisation to the particulars. Although for the purposes of convenience we treat each separately, they are really complementary; deduction is impossible without previous induction, and induction is of no particular value unless it is followed by deduction. In fact, we can only arrive at the meaning of a general statement by applying it to particular cases, and we can never be sure what a general statement implies until we have seen what conclusions it is possible to draw from it.