The argument from improbability is the big one. In the traditional guise of the argument from design, it is easily today's most popular argument offered in favour of the existence of God and it is seen, by an amazingly large number of theists, as completely and utterly convincing. It is indeed a very strong and, I suspect, unanswerable argumentbut in precisely the opposite direction from the theist's intention. The argument from improbability, properly deployed, comes close to proving that God does not exist. My name for the statistical demonstration that God almost certainly does not exist is the Ultimate Boeing 747 gambit. The creationist misappropriation of the argument from improbability always takes the same general form, and it doesn't make any difference
[if called] 'intelligent design' (ID). Some observed phenomenonoften a living creature or one of its more complex organs, but it could be anything from a molecule up to the universe itselfis correctly extolled as statistically improbable. Sometimes the language of information theory is used: the Darwinian is challenged to explain the source all the information in living matter, in the technical sense of information content as a measure of improbability or 'surprise value'
However statistically improbable the entity you seek to explain by invoking a designer, the designer himself has got to be at least as improbable. God is the Ultimate Boeing 747.
The whole argument turns on the familiar question 'Who made God?'
A designer God cannot be used to explain organized complexity because any God capable of designing anything would have to be complex enough to demand the same kind of explanation in his own right. God presents an infinite regress from which he cannot help us to escape. This argument
demonstrates that God, though not technically disprovable, is very very improbable indeed.