Self-love may stand in a threefold relation to love of God. In the first place, it is contrary to love of God when a man makes love of his own welfare his final aim. In the second place, it is included in love of God when a man loves himself for God’s sake and in God. In the third place, it is different from love of God, but not opposed to it, when a man loves himself from the point of view of desiring his own welfare, but does not make this welfare his final aim. In the same way there is also a kind of love towards one’s neighbour besides that which is based upon God, such as exists when a man loves his neighbour because of his attractiveness or on the ground of kinship.
— Thomas Aquinas