Is the Sexual Revolution the Source of Moral Relativism?

Matthew Anderson at Mere Orthodoxy has a 5 minute video of philosopher Peter Kreeft in which he suggests that the basic source of moral relativism is sex and that the most important weapon the Church has at its disposal today in John Paul the Great's Theology of the Body. Watch it here.

Matthew isn't sure that he agrees with everything Kreeft is saying here. My take is that, while there are more complex philosophical and historical roots of relativism that need to be explored, Kreeft is right to say that the kind of moral relativism that we see all around us today in popular culture does arise primarily from the sexual revolution of the 1960's. The sexual revolution was the time when the relativistic, amoralism which had been confined to the ivory towers hit the streets.