What Is Atheism?
Two quite different issues need to be addressed with regard to the sentence “God exists.” One is whether or not the sentence expresses a proposition (something that is true or false and that can be believed or disbelieved). If we say, “Yes, it expresses a proposition,” then the second issue comes in: Is that proposition true or false?
On the first issue, there are three possible positions. One could say, “Yes, ‘God exists’ expresses a proposition.” Let us call that “theological cognitivism” or, in the present context, “cognitivism” for short. Alternatively, one could say “No, ‘God exists’ does not express any proposition.” Let us call that “(theological) noncognitivism.” A third position stays neutral on the matter and declares that there is insufficient data to go one way or the other. Let us call that “general agnosticism.”
Given a cognitivist position on the first issue, the second issue arises: Is the proposition that God exists true or false? Let us call the claim that it is true “theism” and let us call the claim that it is false “atheism.” A third position stays neutral on the matter and declares that there is insufficient data to go one way or the other. Let us call that “cognitivist agnosticism.” Thus, my answer to the question “What is atheism?” is that atheism is the claim that the sentence “God exists” expresses a false proposition, and that claim should be understood in opposition to four other possible positions: noncognitivism, general agnosticism, theism, and cognitivist agnosticism.
Some writers on this topic take the term “atheism” to refer merely to a lack of theistic belief. That would be a kind of catch-all use of the term. Atheism would then include not only the view that “God exists” expresses a false proposition, but also noncognitivism, general agnosticism, and cognitivist agnosticism. Not only would such a definition blur and neglect all those distinctions, but it would also be a departure from the most common use of the term “atheism” in English. For these reasons, it is an inferior definition. For a word to represent the lack of theistic belief, I recommend “nontheism” for that purpose. It is a word that does not already have some other use in ordinary language.
I shall proceed to use the term “atheism” as I defined it above, but it should be realized that all the issues I have mentioned need to be relativized to some specific definition of “God.” Given one definition of the term, atheism may be true, but given a different definition of “God,” noncognitivism may be true. One of my main claims here is that there are definitions of both kinds: some with respect to which atheism is true and some with respect to which noncognitivism is true.
Should Atheism Be Defended?
Given that atheism is true, I would say, “Yes, it ought to be defended against all the various objections that might be raised against it.” The main objection comes from theism and cognitivist agnosticism, claiming that there is no good reason to deny God’s existence. To defend against that objection would require formulating cogent arguments for God’s nonexistence. Another objection could come from noncognitivism and general agnosticism, claiming that there is no good reason to maintain that the sentence “God exists” expresses a proposition. Although that objection is more technical and esoteric and is not well known, certainly it, too, should be defended against if ever it were to be raised.
How about defending nontheism? We need to first ask what it might mean to defend nontheism. I would take that to be equivalent to attacking attempts by theists to support their position. One could attack such attempts by arguing that “God exists” does not express any proposition at all. Or, alternatively, and more commonly, one could attack such attempts by granting that “God exists” expresses a proposition but maintaining that that proposition has not been adequately supported. Note the difference with atheism here. To defend atheism is to put forward arguments (against the challenge of theists and agnostics) to show that the proposition that God exists is false, whereas to defend nontheism is to put forward objections to theistic arguments, thereby aiming to show merely that the given proposition has not been adequately supported. Both tasks are worth doing.
Why should atheism (and nontheism) be defended against the various objections? Obviously, because the truth should be disseminated and made as widely known as possible. “Knowledge is power” and “the truth will set you free!” If the truth is being challenged and is in need of defense, then there must be people who lack knowledge of the truth. It would be in their interest and in the interest of society for them to come to acquire such knowledge. Ignorance is bad and education is good. People need to exercise their critical thinking faculties and develop a more scientific and skeptical outlook on reality. The current wide reliance on faith and authority in people’s thought processes is bad for individuals and bad for society. Being exposed to atheistic arguments would benefit people with regard to their intellects. And that applies to deists and religious humanists as well as to those who are staunch theists.
Where Should the Defense of Atheism Fit Among One’s Priorities?
I shall talk here of “defending atheism,” but it should be noted that all that I say could also be applied to the defense of nontheism. It might be objected that even if atheism is true and even if there is some merit in disseminating that truth among those who are ignorant of it, there are other things to do that are still more important. For example, it is sometimes suggested that a more beneficial use of one’s time, instead of defending atheism, would be to defend the separation of church and state. Such an action would be more beneficial, it is claimed, because it would have a more direct impact on social problems, especially ones that have to do with discrimination against nonbelievers. “We should be battling (a creeping) theocracy, not theism” is the rallying cry.
I have two main objections to this line of thought. First, there is no incompatibility between defending atheism and defending the separation of church and state. One could do both actions on different occasions. For example, one could defend atheism if one finds oneself in a situation in which atheism is under attack and defend church-state separation if one finds oneself in a situation in which that is under attack. If a theist or an agnostic were to challenge me to put forward cogent arguments for atheism, then I would not walk away from the challenge or try to change the subject to church-state separation, but would try to meet it head on.
Second, converting people to atheism indirectly serves the purpose of defending church-state separation (or “battling theocracy”), for no atheists are in favor of theocracy or against church-state separation. On the other hand, to defend church-state separation does not in any way defend atheism, not even indirectly. One “kills two birds with one stone” by defending atheism, but not by defending church-state separation. Even if one does not succeed in converting the other guy on the spot when one defends atheism, one might plant seeds of doubt that develop later on. And those seeds of doubt could have the effect of later converting the guy to the cause of church-state separation. A further point here is that it is questionable whether church-state separation will ever be fully achieved so long as the U.S. society is overwhelmingly theistic in its orientation. It is an arguable position that such an event will happen only when the theistic orientation is considerably reduced (say, to below 50%). It is clear, then, that the defense of atheism has an essential role to play here.
My answer, then, is that the defense of atheism should be a very high priority. Certainly groups like Americans United for the Separation of Church and State are doing important work. But other groups, like the Brights and the Internet Infidels, which include the defense of atheism among their activities, are also doing important work. We should support all of the secular projects and not try to put any of them down in preference to others.
 On this topic, see my Internet essay “Atheism, Agnosticism, Noncognitivism,” The Secular Web (1998) /library/modern/theodore_drange/definition.html.
 One place where atheism is defended against this latter sort of objection is in chapter 3 of my book Nonbelief & Evil: Two Arguments for the Nonexistence of God (Prometheus Books, 1998).