[64] Therefore, the Scripture charges him who has half perfection (for the number fifty is perfect, and the number twenty-five is the half of fifty), to work and to do what is holy, approving his ministration by his works. And the beginning, as an old writer has said, is half of the whole. But the perfect man it does not enjoin to labour any longer, but only to preserve what he has acquired by labour and diligence. For [50] may I never become a practiser of what I ought not to be a preserver;