Separate the Art From the Artist
A saying used when one tries to distance his favorite piece of art from the artist himself (this could usually be because the artist is a terrible person or has committed a horrible crime).
The Mists of Avalon by Marion Zimmer Bradley is one of my favorite books. But I'm not sure how comfortable I feel reading it now since the author herself was exposed as an incestuous child molestor 16 years after her death. So I guess it really would be important to separate the art from the artist.