The aim of this article is to show how the concept of »measure«, which is one of the most intricate and manifold philosophical concepts, started acquiring ethical meanings in the course of Greek philosophical thought. In the first part it is discussed how the word »measure« (μέτρον) and its cognates refer exclusively to concretely measurable quantities in Homer’s epics. The second part deals with the switch of meaning that started happening in the Pythagorean thought. In this part more attention is paid to historical references of emergence of the Greek polis for which the virtue of temperance was indispensable. In this context fragments of Philolaus and Archytas are more closely observed because they point to political importance of measure and measurement. The third part is dedicated to analysis of the relevant passage in Plato’s Statesman (283b-285c) in which Plato distinguishes between two concepts of measurement: one numerical (which measures number, length, size etc.) and the other, which can be called »deontic«, which measures more and less with respect to the »right measure« (τὸ μέτριον). The second kind of measurement is also ethical because it includes various judgments of purpose, goals, and human nature.