The argument from imperfection is the argument that if God existed then the world would be perfect, that the world isn‘t perfect, and so that God doesn‘t exist. The claim that if God existed then the world would be perfect rests on the fact that God is conceived of by theists as being a perfect Creator.

A perfect Creator, the argument from imperfection suggests, is one that creates a perfect world. One that creates an imperfect world is therefore an imperfect Creator. This imperfect world, therefore, even if it was made by some Creator, was not made by God as he is conceived of by theists. The God of theism, therefore, does not exist.

One response to the argument from imperfection is to deny that there is such a thing as a best possible world. If there is no best possible world, then even a perfect Creator would not create the best possible world, in which case it would not follow from the fact that a given world is imperfect that that world was not created by a perfect Creator. Specifically, it would not follow from the fact that this world is imperfect that it was not created by God. The argument from imperfection would have been defeated.

The claim that there is no best possible world, that the idea of a perfect world is incoherent, is at least plausible. Although there are better and worse possible worlds, for any world that we can imagine we can imagine a way of making it better. We could for instance, increase the number of happy people contained by that world. As there is no intrinsic maximum number of happy people in the world, there is no world for which it is not possible to increase the number of happy people that it contains.

Further, increasing the number of happy people in a world always makes that world better. It is therefore true of every world that it could be improved, and so true of no world that it is the best possible world. Thus far, the defence against the argument from imperfection appears to be on solid ground.

The concern with this defence against the argument from imperfection is that it proves not only that the idea of a best possible world is incoherent, but also that the idea of a perfect Creator is incoherent. If this is the case, then the fact that there is no possible world not only rebuts the argument from imperfection but also disproves the existence of God. For if God is conceived of as a perfect Creator and if the idea of a perfect Creator is incoherent, then the existence of God is impossible.

If the theist is to answer the argument from imperfection by denying that the concept of a best possible world is coherent, therefore, then he must find some way of explicating the concept of a perfect Creator that is not dependent upon the concept of a best possible world.