Abstract
We propose in this article some new elements for the interpretation of Heraclitus' doctrine, concerning in particular the role of the opposition of contraries as generator of harmony, that results from Fragments 8DK and 51DK. This interpretation is based on the conceptual tool of matrices of concepts. After having described the basic elements that govern the latter, we set out to define in this conceptual framework the notions of opposition and contrary, as well as of harmony. This allows us to give an interpretation and also a justification of Heraclitus' specific doctrine, according to which the opposition of contraries generates harmony.