Arnauld, Antoine (1612–94)

4. Correspondence with Leibniz

This same concern for safeguarding God’s omnipotence and freedom is also apparent in Arnauld’s critical remarks on Leibniz’s metaphysics. In 1686, seeking to enlist Arnauld’s support for his ecumenical project of bringing about a reconciliation of the Catholic and Protestant faiths, Leibniz sent a summary of his Discours de la métaphysique to Arnauld. Among the propositions upon which Arnauld focused was one related to Leibniz’s notion of substance: that the individual concept of every person involves, once and for all, everything that will ever happen to them. Arnauld responded by saying that if that is so, then ‘God was free to create or not to create Adam, but supposing he decided to create him, all that has since happened to the human race or which will ever happen to it has occurred and will occur by a necessity more than fatal’ (Montgomery 1980: 73). God, having chosen to create Adam, therefore has no freedom or control over the course of events that constitutes the history of the world, since it all apparently follows necessarily from the concept of the first human. Arnauld suggested that Leibniz should cease such metaphysical speculations and think seriously of the condition of his soul and of entering the fold of the Catholic Church. Fortunately their correspondence continued, and Arnauld’s objections and queries – concerning necessity, divine providence, causality, the being of possibles, the nature of individual essences and the distinction between essential and accidental properties – led Leibniz to think more deeply about many of his doctrines, and were certainly of great importance in the development of Leibniz’s mature metaphysics (see Leibniz, G.W. §1, 4, 6–7).