_Manichaean Games._--Take any game played by two persons, such as draughts,
and let the play be as follows: each plays his best for himself, and
follows it by playing the worst he can for the other. Thus, when it is the
turn of the white to play, he first plays the white as well as he can; and
then the black as badly (for the other player) as he can. The black then
does the best he can with the black, and follows it by the worst he can
{290} do for the white. Of course, by separating the good and evil
principles, four persons might play.