There must, however, exist a science whose aim is to discover and teach the method of how to investigate, through correct reasoning, what is not known from what is known. It cannot be metaphysics because this science regards things apart from motion. A syllogism, however, is a kind of motion where the properties are deduced from the subject(-matter) and the conclusion from the premises (NLP prologue, 4). That science is logic. Since logic has the task of discovering a method of knowing that can