In masturbation there is nothing but loss. There is no reciprocity. There is merely the spending away of a certain force, and no return. The body remains, in a sense, a corpse, after the act of self-abuse. There is no change, only deadening. There is what we call dead loss. And this is not the case in any act of sexual intercourse between two people. Two people may destroy one another in sex. But they cannot just produce the null effect of masturbation.
Ordinary love is mere animal attraction. Otherwise why is the distinction between the sexes? If one kneels before an image, it is dreadful idolatry; but if one kneels before husband or wife, it is quite permissible!
Sex was always surrounded by taboos, and I don't see it necessarily as a manifestation of evil. I think that sexuality is first and foremost the way that God chooses for us to be here on earth, to enjoy this energy of love in the physical plane.
In spite of conflicting signals - and in spite of a popular culture that sometimes puts down their innocence - most of our kids are good kids. Large numbers do volunteer work. Nearly all believe in God, and most practice their faith. Teen pregnancy and violence are actually going down. Across America, under a program called True Love Waits, nearly a million teens have pledged themselves to abstain from sex until marriage.
The sex illusion is not a fixed quantity: not what mathematicians call a constant. It varies from zero in my wife's case to madness in that of our stepsister.