But he was most cautious - if candidates were married, it had to be both spouses.  An unmarried candidate had to be sexually attractive as well as sexually aggressive - and he impressed on his priests that the males must always equal or exceed in number the females.  Nowhere is it admitted that Foster had studied the histories of earlier, somewhat parallel cults in America but he either knew (or sensed) that most of such had foundered because the possessive concupiscence of their priests led to male jealousy and violence.  Foster never made this error; not once did he keep a woman entirely to himself, not even the women he married legally.