Abstract
Anaximander of Miletus is the author of the one of the first Greek books with the theme of nature. He is the person at the very beginning of the Ionian „investigation into the nature“, as well as the philosophy.
Although only few words from his book are preserved until today, the fragment DK 12 B 1 is considered to be the first philosophical text. The study offers the translation of the main part of the textual heritage of Anaximander and explicates the themes connected with his thought and work.
The term to apeiron is interpreted in the sense of the boundless nature on the background of the thought of the opposites and according to the fragment DK 12 B 1, which articulates cycles of the world. At the same time the study exposes character of the Ionian thought and its starting points in astronomy, meteorology using the geometry and being in accord with the language of religion.