Possibly, however, it was not.

Possibly he did not think it worth the trouble to call his will into play.

Why should he, after all?
As long as he might not live in Berlin, what did it matter where he lived?
and Paris was as good a place as any other.

To have resisted Pilar's persuasions would not have been an evidence of strength, but simply the obstinacy of a conceited fool, who wants to prove to himself that he is capable of setting somebody else at defiance.

So that after all he was going to Paris because he wished it, or rather, because he saw no reason for not doing so.