No one, nor anything, obliges the Christian to busy himself with science, art, or philosophy, for other ways of serving God are not wanting; but if that is the way of serving God that he has chosen, the end itself, which he proposes for himself in studying them, binds him to excellence . . . That is the only way of becoming a good servant. . . . [T]he intelligence is good, but it is only so if, by it and in it, the whole nature turns toward its end, which is to conform itself to God . . . [but] by taking itself as its own end, the intelligence has turned away from God, turning nature with it, and grace alone can aid both of them in returning to what is really their end, since it is their origin. The ‘world’ is just this refusal to participate in grace, which separates nature from God, and the intelligence itself is of the world insofar as it joins with it in rejecting grace.