1. The Necessity of God’s Existence Daniel von Wachter http://daniel.von-wachter.de

2. The traditional claim “God exists necessarily” (GN) The intuition: God’s non-existence is not a possible alternative. The question: How should “God exists be interpreted”, and is it true? I shall not discuss ontological arguments. I shall not give arguments for theism. If there is a God, does he exist necessarily?

3. Historical examples: Anselm Anselm of Canterbury (1033-1109): “You exist so truly, my Lord God, that you cannot even be thought of as not existing... Whatever exists except you alone can be thought of as not existing. You alone... enjoy existence to the fullest degree of all things... everything else enjoys being in a lesser degree. (Proslogion, ch. 3)

4. Historical examples John Duns Scotus: “You [Lord] are uncaused, ingenerable and imperishable; you cannot possibly not exist, because you are neces-sary being from yourself (ex te necesse esse)” (Tractatus 91) Thomas Aquinas: God is identical with his essence and his being. Leibniz: Whilst created world exists contingently and depends on God, God exists necessarily and depends on nothing. He exists of “absolute and metaphysical necessity” and is the last cause of everything. (De origine...)

5. Today Contemporary philosophers usually reject the view that God exists necessarily. They use the concept of necessity from logical empiricism, namely “logical necessity”. I shall explain the LE doctrine, criticise it, propose a different concept of necessity, and argue that God exists necessarily in this sense.

6. Logical empiricism LE was exported by AJ Ayer and was soon dominating. The rival view was not exported and never prominent. LE reacted against phenomenology (Husserl, Scheler) and rejected necessity claims about the world (e.g. nothing can be green and red all over). Why? Empiricist creed: all knowledge about the world comes from the senses. The phenomenologians’ knowledge of necessities about the world is supposed to be a priori (Wesensschau). LE found this utterly mysterious!

7. Logical empiricism (cont) There are no true modal statements about the world. However, there are tautologies, analytic statements, whose truth is due solely to the definitions of the terms contained. In a philosophical coup d’etat LE substituted necessity by analyticity and called it “logical necessity”. “Nothing can be green and red all over” is analytic. “Bachelors are unmarried” is accepted as paradigm of necessity in the strongest sense.

8. Logical empiricism (cont) Since then philosophers interpret “necessarily p” as “analytically p” (or “non- p is self-contradictory”) E.g. the question whether backward causation is possible is taken to be the question whether “A at t2 caused B at t1” is self-contradictory.

9. (GN) in post-Ayer philosophy “God exists necessarily” is taken to be the claim that “God exists” is analytic. Findlay “Can God’s existence be disproved” (1948): –If God existed he would exist necessarily –“God exists” would be analytic –It is not analytic –There is no God

10. The right response It is true that “God exists” is not analytic. True necessity statements are not analytic. The kind of necessity relevant for philosophy is synthetic necessity.

11. Synthetic necessity A synthetic necessity claim is one of the form “necessarily p” where p is synthetic. Ordinary as well as philosophical modal statements are synthetic. E.g. the question whether backward causation is possible arises only if “A at t2 caused B at t1” is consistent. Why are there true synthetic modal statements?

12. Synthetic necessity Humans have the peculiar ability to conceive of things, to form concepts. Further, they can combine concepts (consistently) to form new concepts. Given a concept one can ask whether there is something that falls under it. For a given concept there is not only the question whether there is something that falls under it, there is also the question whether it is possible that there is something that falls under it. Hence every existence statement, e.g. “there is something that is green and red all over” or “There is a God”.

13. When is “x exists necessarily” true? If x once did not exist it does not exist n.ly Something may exist at all times but not exist necessarily. Something exists necessarily only if it is imperishable. God is imperishable if –it is impossible that he will be abolished –it is impossible that he will commit suicide –it is impossible that he will cease to exist by accident.

14. Defence of the premises needed God did not begin to exist. –If he had begun there would be something before beyond his control. God is imperishable. –One could defend this by deriving it from everlastingness being part of the concept (or “nature”) of God. But that is begging the question. It is impossible that God will be abolished. –He is powerful enough to avoid that. It is impossible that God will commit suicide. –He has overriding reason for not doing so. It is impossible that God will cease by accident.

15. God exists necessarily 1.Up to some time in the past, God has always existed 2.It is impossible that he will be abolished 3.It is impossible that he will commit suicide 4.It is impossible that he will cease to exist by accident. God exists necessarily.

16. An alternative argument God is cause of everything and has no cause Hence there is nothing that exists without God bringing it into being and sustaining it. When there is no God there is nothing. Assumption: if there are no things, then there is no time. Hence there is no time when there is no God.

17. An alternative argument (cont) 1.God is cause of everything and has no cause 2.If there are no things there is no time God exists necessarily.

18. Anselm again It is often assumed that Anselm’s claim that God exists necessarily is identical with his claim that existence is part of the concept of God. But Anselm distinguishes them. Anselm: x exists necessarily iff x has no beginning, x has no end, and x is not made up of parts [and hence cannot be destroyed] (Reply to Gaunilo 4)

19. Could God’s existence still be a “cosmic accident”? Some may say “God’s existence could still be a gigantic cosmic accident (Alston), because it is not logically necessary” LN is not trivially stronger than SN because what is logically necessary is not synthetically necessary. Is the “necessity” in “There cannot be a married bachelor” really stronger than the necessity in “Nothing can cause something earlier”?

20. The lesson God exists necessarily (if he exists at all) Further suggestions –Logical necessity is not stronger than synthetic necessity –“Logical necessity” does not deserve to be called “necessity” –Modal questions arising in philosophy are about synthetic modality