Bill Vallicella, the Maverick Philosopher, has criticized the tendentious redefinition of atheism as “lack of belief in the existence of God.” His main reason is that it reduces atheism to a psychological fact that person P factually lacks a belief, rather than a propositional position that can be argued or criticized.
Is atheism true, on this redefinition? Yes, some people lack a belief in God. Of course, theism (suitably redefined as “having a belief in God”) is also true: some people have a belief in God. So both atheism and theism are true, since thanks to this game of redefinition, they say nothing more than “there are atheists” and “there are theists.”
Vallicella suggests this strategy, when confronted with a “lack of belief” atheist. Simply give him the term “atheist,” and note that it is completely uninteresting philosophically that some people factually lack a belief in God. Next, define antitheism as the positive affirmation of the proposition “God does not exist,” and ask the “atheist” whether or not antitheism is true.
In other words, simply give up the term “atheism,” and define antitheism as a synonym for the older pre-Flewian definition of atheism and talk about that instead. If “atheism” means what the redefiners say it does, then it’s not a philosophical position, so it’s not conceptually interesting.
If you do this, the two opposed propositional positions will be theism and antitheism, whereas “atheism” (in the new sense) will simply be irrelevant.
This seems like a fairly good strategy. It gives the “atheist” a meaningless verbal victory, while at the same time allowing one to discount “atheism” as he defines it as virtually meaningless and philosophically uninteresting.
If one wishes, one can keep “theism” or redefine it parallel to “atheism,” making it also irrelevant and uninteresting.
Then one can argue the positions of antitheism and protheism.