All atheists assert, so far as I can tell, that MATTER PRECEEDS MIND. But I think it is tricky to assert that if one begins all one’s reasoning on the presumption that matter preceeds the existence of mind, that one has not done something METAPHYSICAL—and even engaged in an act of FAITH.
In other words, atheism, like theism, starts with a metaphysical premise that is not really accessible to proof, but must nevertheless be asserted as an axiom before one can say much of anything further (intellectually).
Sartre’s metaphysical premise is (famously): “Existence preceeds essence.” In other words, we are free beings, and not essential beings (determined). I don’t really see how one arrives at this by inductive or deductive proof—one has to accept it as a metaphysical starting point (as I do).
The same is true of the atheist axiom: matter preceeds mind; or existence preceeds mind.
One might point to suggestive things in its favor, but it is more a metaphysical premise than something self-evident or discovered by a sustained and thoroughly convincing appeal to inescapable reasoning. Why there should be anything at all is an utter mystery, but atheists have an opinion on it. That opinion is this: matter just has always been, or came into existence of itself, and over time, varied, MULTIPLIED, and interacted with itself, and can now be observed to function by self-generated and predictable “laws.” Oh, and by the way, the vissitudes of the eons have (lucky for us) produced minds, and love, and philosophy, and Richard Dawkins, and William Shakespeare.
It sounds improbable and metaphysical, doesn’t it?
In this sense, because atheism’s beginning axiom is no more subject to proof (or even probability) than is theism’s (and, indeed, they are the mirror opposites of one another) it seems reasonable to call both atheism and theism competing THEORIES that try to account for the universe based on a singular premise (either matter preceeds mind or mind preceeds matter).
Thus, if you are an atheist, how do you know if you are a hundred miles ahead of your opposition (intellectually)—or a hundred miles behind? Likewise, the same question applies to the theist.
To be an agnostic is to acknowledge that, when it comes to ultimate questions, we are pretty much groping in the dark, and our stabs at explanation may not just be wrong, but wildly wrong.