When we inquire after the origin of something, there must be at least two states to consider: the one before this something came into being and the one after that. So an investigation into the origin of logic means that in a sense we draw a line: the state before that line is a world in which there is no logic, while the state after it is a world in which there is logic. And the investigation as a whole will then show how the world changed from the former state to the latter.

In this talk I will Illustrate my general idea how to deal with this topic with an investigation of Aristotle’s views on logic in his Prior Analytics and his On Interpretation. I will investigate what are the basic terms concerning logic that Aristotle uses in these two works, and then describe how one can extend the investigation using these terms. I will evaluate the results by comparing them with some intuitive constraints.