There Is Nothing On This Earth

Thomas Aquinas makes this claim in the Summa Contra Gentiles (Book III, Chapter 125), a systematic defence of Christian theology written partly to address Islamic and Jewish philosophical objections. Aquinas argued that friendship (amicitia) is among the greatest natural goods because it is through friendship that we share in the highest goods — reason, virtue, and ultimately our orientation toward God. He drew heavily on Aristotle's account of friendship in the Nicomachean Ethics, integrating it with a Christian theology of charity (caritas) as the highest form of friendship: love of God and neighbour.