Love all men, even your enemies; love them, not because they are your brothers, but that they may become your brothers. Thus you will ever burn with fraternal love, both for him who is already your brother and for your enemy, that he may by loving become your brother.
Saint AugustineEveryone who observes himself doubting observes a truth, and about that which he observes he is certain; therefore he is certain about a truth. Everyone therefore who doubts whether truth exists has in himself a truth on which not to doubt.... Hence one who can doubt at all ought not to doubt the existence of truth.
Saint Augustine