To: Pearl K.
From: Geoffrey Klempner
Subject: Leibniz's claim that this is the best possible world
Date: 14th May 2009 13:08

Dear Sachiko,

Thank you for your email of 14 April, with your essay for the University of London Modern Philosophy: Spinoza, Leibniz and Kant paper, in response to the question, 'Does Leibniz make a convincing case for his claim that this is the best of all possible worlds?'

You have indeed missed out a step. The first step in Leibniz case is his proof of the existence of God. I would have thought that was rather important. The proposition to be proved is not, 'This is the best of all possible worlds, IF God exists.'

The second thing you need to say is that both the argument for the existence of God and the argument that this is the best of all possible worlds come from the same source: the Principle of Sufficient Reason.

There has to be a sufficient reason why there is a world rather than no world. Indeed, the same is true of the tiniest detail about this world. There has to be a sufficient reason why I am writing this email to you today. Every explanation that one could give merely pushes the question back to the explanans: there has to be a sufficient reason why that is the case rather than not the case.

God is the only possible entity which is or contains a sufficient reason for its own existence.

Obviously, there is room for objection along the lines of criticism levelled at the cosmological argument. Using the language of 'sufficient reason' rather than cause and effect might make the argument seem more persuasive. We are not assuming that there is an entity, God, which caused another entity, the world, to come into existence. But however you cash this, in the end we are pushed back to the ontological argument, as Kant argued. It requires the ontological argument to license the claim that there can be, logically, an entity which is or contains a sufficient reason for its own existence.

The world exists rather than not existing because of God. And the world is arranged this way, rather than some other way it might have been arranged because God only does things, by definition for which there is a sufficient reason.

So, why can't there be an evil god, who creates the worst of all possible worlds? We have to appeal to the ontological argument once again: God is infinitely perfect and therefore can only do good, not evil.

As critics argued, it seems that we can imagine many ways in which the world might have been better. Leibniz has a blanket reply to this which is that we are only finite and cannot fathom God's purposes. But this invites a further, lethal criticism. The argument just given can always be applied, in any circumstances. It doesn't matter how bad things get; the hypothesis that this is the best of all possible worlds is irrefutable by any possible course of human experience. In that case, one might argue, it has no content at all. There is no reason to marvel at God's creation, no reason to find comfort or inspiration in the grandeur of nature, or great works of art, or saintly or heroic deeds.

This is different from the point which you address, an objector who says that this is the 'best' possible world only because God says it is. We can accept, for the sake of argument, that God chooses between worlds by some suitable criterion of 'better' or 'worse', and his nature being such as it is, there is no logical possibility that God could ever make any decision for which there is not a sufficient reason. But all that is irrelevant, because the claim in question is meaningless.

Imagine the most evil disgusting world -- the world of DOOM where you are the only human being left alive, heavily wounded, defending yourself with a chainsaw and shotgun against a relentlessly spawning army of monsters -- and Leibniz's argument would still apply with exactly the same force. What have you got to complain about. You're still alive, aren't you?

The stark truth is that there is no limit to how bad things can get. We go around imagining that we are in a kind of protective bubble. Leibniz's language strongly supports that illusion. Everything is for the best in the best of all possible worlds. (To which Voltaire ironically responded in his novel 'Candide', '...and everything in it is a necessary evil'.) But that claim has no empirical cash value. If the Nazis had won World War II, it would have been for the best. If and when the sun explodes, devouring the earth, it will be for the best in the best of all possible worlds.

All the best,

Geoffrey