Returning is becoming

That identity not be first, that it exists as a principle but as a second principle, as a principle become; that it revolve around the Different: such would be the nature of a Copernican revolution which opens up the possibility of difference having its own concept, rather than being maintained under the domination of a concept in general already understood as identical. Nietzsche meant nothing more than this by eternal return. Eternal return cannot mean the return of the Identical because it presupposes a world (that of the will to power) in which all previous identities have been abolished and dissolved. Returning is being, but only the being of becoming.

Gilles Deleuze, Difference and Repetition (Continuum, 2004) p. 50