Full Idea
Where do we get the concept of God as the highest good? Solely from the idea of moral perfection, which reason traces a priori.
Gist of Idea
We judge God to be good by a priori standards of moral perfection
Source
Immanuel Kant (Groundwork of the Metaphysic of Morals [1785], 408.29)
Book Reference
Kant,Immanuel: 'The Moral Law (Groundwork of Morals)', ed/tr. Paton,H.J. [Hutchinson 1948], p.73