It was not until I had attended a few postâ€mortems that I realized that even the ugliest human exteriors may contain the most beautiful viscera, and was able to console myself for the facial drabness of my neighbors in omnibuses by dissecting them in my imagination.
J. B. S. Haldane
I got that one from a book on thought-experiments [amazon]. How have I not come across it in a book about serial killers? I read both sorts of books, like any person with normal beliefs and desires, healthy impulses and interests.