Aristotle - Prior Analytics

Prior Analytics is the third of Aristotle's six texts on logic which are collectively known as the Organon («Instrument»). In Prior Analytics Aristotle conducts a formal study of arguments. In logic an argument is a series of true or false statements which lead to a true or false conclusion. Aristotle identifies valid and invalid forms of arguments called syllogisms. A syllogism is an argument consisting of three sentences: two premises and a conclusion. Of the entire Aristotelian corpus, Aristotle gives priority to the study of his treatises on Logic. (Adapted from Wikipedia)