What's a quote (in book 2) that shows support of why the doctor says that "change happens on the inside"?

"I own to you that just then I perceived - in a new light, as it were—how unwholesome the pilgrims looked, and I hoped, yes, I positively hoped, that my aspect was not so - what shall I say?—so—unappetizing: a touch of fantastic vanity which fitted well with the dream-sensation that pervaded all my days at that time." Ch 2

Marlow is discovering just how much the white pilgrims, his own kind, repel him.