The mature Rawls viewed St. Thomas Aquinas’ Summa Theologiae as a “magniicent” achievement. Just as Leibniz rendered the scientiic discoveries of the seventeenth century compatible with Christian orthodoxy, Aquinas (1225–1274) confronted the new Aristotelianism of the thirteenth century so as to restate Christian theology in Aristotelian terms (LHMP 12, 106).

This praise of Aquinas contrasts with the very early Rawls, who opposed the naturalism of Plato, Aristotle, Augustine, and Aquinas to Christian personalism. Rawls defended the latter and denigrated the former. By “naturalism” Rawls did not mean “materialism.” Rather, naturalists like Aquinas were those who saw human beings as essentially oriented toward an abstract good instead of toward a personal God (and toward human persons). The danger, he thought, was that naturalists like Aquinas turned God into an object and, because of this depersonalized character of naturalism, encourage egoism and hence the destruction of community (BIMSF 119–120, 161–162, 178, 182, 189, 209, 217, 220–221).

Both the very early Rawls and the 1997 Rawls of “On My Religion” opposed the predeterminism of Aquinas (alleged to be every bit as severe as that of Calvin) as well as Aquinas’ effort to offer rational proofs for God’s existence. Throughout his life Rawls seemed to remain a ideist (BIMSF 224, 247, 263–264).