The article reopens the question of the reconstruction and interpretation of the beginning of Heraclitus' fragments B1 and of fragment B 2. More particularly, we propose a new reading of the key phrase DEONTOS, connected with the Logos.
We argue that it could well mean 'binding' and not 'existing' as it is usually interpreted. The textual transmission as well as the overall context of the both fragments in question is also discussed.