From Anaïs Nin’s A Spy in the House of Love:

He turned his eyes fully upon her, now a glacial blue; they were impersonal and seemed to gaze beyond her at all women who had dissolved into one, but who might, at any moment again become dissolved into all.  This was the gaze Sabina had always encountered in Don Juan, everywhere, it was the gaze she mistrusted.  It was the alchemy of desire fixing itself upon the incarnation of all women into Sabina for a moment but as easily by a second process able to alchemize Sabina into many others.