John Paul II offers a profound and subtle analysis of the  the sources of sexual deviance in his theology of the body.  The steps are:

1. Lust is a disorder of the spirit, and breaks the natural bond between body and soul.  Men no longer act as single simple beings, their bodily actions an expression of a person.

2. This is linked to shame.  Due to the breakdown of the unity of spirit and body, human beings lose the confidence that their bodies express their persons.  Lacking such confidence in the “spousal meaning of the body” and the gifted character of creation, men want to hide their bodies from visibility.  They no longer are certain of their right to signify their presence in the visible world, no longer confident of being images of God.

3) Yet, there remains a desire for union.  The self-communicative nature of bodily actions, particularly of sexual knowledge, isn’t erased by sin.  But lust distorts that desire.  Instead of pursuing sexual union as a means of self-expressing self-gift, men pursue sexual union as self-gratification carried out on an “object” (not another subject) of desire.  Because of shame, however, a screen is erected between men and women, and so that union is never satisfied.  It becomes an insatiable desire.

4) In the process, of course, men and women become objects of mutual lust.  The goal of sex is not to communicate myself to my beloved, but to take and possess and dominate the “object” of lust.  Genesis 3:16 captures this with the desire of the woman in an inner connection with the domination of the man.  It’s not surprising that a humanity that fell with the seizure of fruit should develop a sexual culture in with seizure and domination are paramount.

5) All of these evils arise from a disorder of the spirit caused by sin.  But the body gets blamed.