The article is an introduction to the Greek philosophical problematic of Hei- degger’s work. The author shows that φύσις is the main notion of the early Greek tradition which appears in An Introduction to Metaphysics. Heidegger turns to Heraclitus to show the Greek experience of the world. He considers the etymology and meaning of φύσις in the context of Heraclitus. He recalls that φύσις is a fundamental Greek word which means being in a whole. The conception of the history of being is of central importance in Heidegger’s thought. As a result the world is a consequence of the working of two powers, πόλεμος and λόγος, two aspects of φύσις. At the same time Heidegger shows the difference between mythology and philosophy.