I was searching Wade Burleson's blog for a different reason and bumped into this:
"Imaginary women are always accessible, always subservient, [give] no call for sacrifice or adjustment, and can be endowed with erotic and psychological attractions which no real woman can rival. Among these shadow brides, the viewer is always adored, always the perfect lover; no demand is made on his unselfishness, no mortification ever made on his vanity. In the end imaginary women become the medium through which he increasingly adores himself. The main work of life is to come out of ourselves, out of the little dark prison of selfishness we are born in, to know God in the center of our being and from that place to offer ourselves for the sake of others. All things are to be avoided which retard this process. The danger of pornography is of coming to love the prison of self."
~ C.S. Lewis
Link to original post: Lewis & Porn