“The point of logic is to give an account of the notion of validity: what follows from what”
(Graham Priest, Introduction to Non-Classical Logic, 2008)
Logic is all about argument and persuasion. It is the formal study of correct patterns of reasoning. Whenever we make a decision, pass a judgment, or express a position, we do so in a fairly patterned fashion. Whether explicitly or implicitly, we start from a set of assumptions and beliefs about something and we use them to arrive at some further belief.