I have previously pointed out that the word “God” is ambiguous in Richard Dawkins’ book, The God Delusion. This oversimplifies the situation a bit, because a close reading of The God Delusion reveals a reference to at least fifteen different kinds of atheism. So, before I go into critique of Dawkins’ main argument, I will briefly spell out these fifteen different kinds of atheism.

A main purpose of The God Delusion, is to convert people to atheism:

If this book works as I intend, religious readers who open it will be atheists when they put it down. (TGD, Mariner paperback edition, p. 28)

Unfortunately, Dawkins never explicitly defines the term “atheism” (at least not in the Preface or first four chapters). Also, his initial attempt to clarify this term in Chapter 1 appears to (mistakenly) equate atheism with naturalism:

An atheist in the sense of philosophical naturalist is somebody who believes there is nothing beyond the natural, physical world … (TGD, p.35)

Later on, in Chapter 2, Dawkins implies a more standard definition of “atheism”: the belief that “there is no God” (TGD, p. 73).

So, the word “atheist” in The God Delusion has at least two different meanings:

(Def1) X is an atheist if and only if X believes that there is nothing beyond the natural, physical world.

(Def2) X is an atheist if and only if X believes that there is no God.

Furthermore, Dawkins points out that atheists ascribe different levels of probability or certainty to their belief. A de facto atheist believes that “God is very improbable” (TGD, p.73), while a strong atheist believes it is certain that there is no God (TGD, p.73). Dawkins implies that there is another position that is halfway between that of de facto and strong atheism: someone who believes, as Dawkins does, that it is almost certain that there is no God (TGD, p.74 & 189). So, Dawkins points to three levels of certainty for atheism: very probable, almost certain, and certain.

These three levels of certainty can be applied to either of the two above definitions of atheism, to yield six different kinds of atheism. So, how do I come up with fifteen different kinds of atheism in The God Delusion? There are at least four different interpretations of the word “God” referenced by Dawkins in this book:

(Def3) X is God if and only if (a) X is a supernatural creator, and (b) it is appropriate for us to worship X. (see TGD, p.33)

(Def4) X is God if and only if (a) X is a superhuman being, and (b) X is a supernatural intelligence, and (c) X deliberately designed and created the universe and everything in it. (see TGD, p.52)

(Def5) X is God if and only if X is a god of any kind (whether as conceived of by polytheism or monotheism). (see TGD, p.56)

(Def6) X is God if and only if X is a person who is (a) omnipotent, and (b) omniscient, and (c) perfectly good. (see TGD, p.101)

Because Dawkins suggests four different meanings of the word “God”, there are four different varieties of atheism in the sense of disbelief in the existence of God (see Def2 above).

So, in The God Delusion, there are five basic types of atheism, each of which can occur in three levels of certainty, which yields a total of fifteen different kinds of atheism:

1. There is nothing beyond the natural, physical world (very probably, almost certainly, certainly).
2. God (Def3) does not exist (very probably, almost certainly, certainly).
3. God (Def4) does not exist (very probably, almost certainly, certainly).
4. God (Def5) does not exist (very probably, almost certainly, certainly).
5. God (Def6) does not exist (very probably, almost certainly, certainly).

So, what sort of atheism is Dawkins trying to prove in The God Delusion? That is not clear, but if I had to pick just one of the fifteen kinds as his main focus, it would be the view that,

God (Def4) almost certainly does not exist.

Dawkins clearly opts for the “almost certainly” level of probability, and Def4 seems very central, because it is based on his precise definition of “the God Hypothesis” which is a central and often used concept in the key chapters of The God Delusion.