In this paper, I argue that Arnauld’s conception of God is more radical than scholars have been willing to allow. It is not the case that, for Arnauld, God acts for reasons, with His will guided by wisdom (much as the God of Malebranche and Leibniz acts), albeit by a wisdom impenetrable to us. Arnauld’s objections to Malebranche are directed not only at the claim that God’s wisdom is transparent to human reason, but at the whole distinction between will and wisdom in God, even if that wisdom were “hidden.” Arnauld’s God, in fact, approaches the extreme voluntarist God of Descartes, and thus transcends practical rational agency altogether.