Ancient Greek philosophy
Philosophy used to be a very comprehensive term, including what have subsequently become separate disciplines, such as physics. (As Immanuel Kant noted, "Ancient Greek philosophy was divided into three sciences: physics, ethics, and logic.") Today, the main fields of philosophy are logic, ethics, metaphysics, and epistemology. Still, it continues to overlap with other disciplines. The field of semantics, for example, brings philosophy into contact with linguistics.