Ever heard of concrete moral truths? They exist. One of them is is that pornography helps create a moral climate conducive to sexual abuse and exploitation. It reduces sex to recreation and human beings to mere playthings and machines. It denegrates the sacredness of marriage, family and human life.
Even those who claim porn is harmless must tacitly acknowledge the power and influence of words, pictures, and ideas. Clearly what we see and hear affects our thinking and influences our behavior--and porn does indeed have a damaging impact on conduct toward women. Ideas do, after all, have consequences.