Aristotle's Prior Analytics book I

Aristotle''s Prior Analytics marks the beginning of formal logic. For Aristotle himself this meant the discovery of a general theory of valid deductive argument a project that he had described as either impossible or impracticable probably not very long before he actually came up with syllogistic reasoning. A syllogism is the inferring of one proposition from two others of a particular form and it is the subject of the Prior Analytics. The first book to which this volume is devoted offers a fairly coherent presentation of Aristotle''s logic as a general theory of deductive argument.