(called the premises) for or against a position (called the conclusion). an inference is a conclusion derived either from general premises (deduction) or from factual evidence (induction). Deduction and induction are both processes of reasoning that we need to understand if we are to avoid serious fallacies in our thinking. they are terms used to describe methods by which we move from evidence to conclusions based on the evidence. Deduction is the process by which we draw a conclusion from one or more premises. if our inference is correct and the conclusion does follow, we say that the deduction is valid. for example, if we say, "all men are mortal" and "socrates is a man," we may conclude that "socrates is mortal." here the premises are all the evidence that is relevant to the soundness of the conclusion. induction, on the other hand, is empirical, in that it deals with matters of fact. it attempts to draw conclusions concerning all the members of a calss after examining only some of them or concerning an unexamined member of a class. the aim is to make statements or propositions that are true. for example, after examining some crows, or even a large number of them, is it valid for us to conclude that all crows are black? may we conclude that the next crow we see will be black?