The Inheritor - Pg 291

   "Your old stereotype devil is no more than horns and hoofs and a goat—the medieval Christian version of the Great God Pan. Pan was harmless—even benevolent. And that's one of the archetypes from the collective unconscious that keeps turning up in the human race's psyche. But the church fathers in the Middle Ages were so inhibited and sexphobic that whenever they got a glimpse of that particular archetype they had to believe it was the devil."
   "Why would they mix up Pan with the devil?"
   "Because the human is the only animal, except the goat, which has full-time sexuality. Other mammals turn it off unless they're breeding. And the goat has always been the archetypal image of unbridled sexuality. Which scared the hell out of your church fathers, who preferred dividing sheep from goats. Pan would be a devil to people whose prime objective was repressing their own sexuality."