Although the two great commandments to love God and to love our neighbors as ourselves are central to Christianity, few theologians or spiritual writers have undertaken an extensive account of the meaning and forms of these loves. Most accounts, in fact, make love of God and love of self either impossible or immoral. Integrating these two commandments, Edward Vacek, SJ, develops an original account of love as the theological foundation for Christian ethics. Vacek criticizes common understandings of agape, eros, and philia, examining the arguments of Aquinas, Nygren, Outka, Rahner, Scheler, and other theologians and philosophers. He defines love as an emotional, affirmative participation in the beloved's real and ideal goodness, and he extends this definition to the love between God and self. Vacek proposes that the heart of Christian moral life is loving cooperation with God in a mutually perfecting friendship.