This topic is way beyond the official remit of this blog, but what the heck, I’m hoping we’ll get some interesting comments on it.

I’ve been trying to grasp the distinction between atheism and agnosticism for some time, and I’ve come to the conclusion stated in the title of this post. My reasoning follows.

Define atheism as “the view that spiritual or supernatural entities, such as God, probably do not exist.” Define agnosticism as “the view that it is not possible to know with certainty whether spiritual or supernatural entities, such as God, exist or not.” Finally, define theism as “the view that at least one spiritual or supernatural entity, such as God, probably does exist.” (The excluded category is the view that a supernatural entity, such as God, is equally likely to exist and not to exist. I’m not sure what to call this view.)

So what is the difference between atheism and agnosticism? I do not believe that any atheist would reject agnosticism as defined here. Is there any atheist who would say with 100% certainty that God does not exist? If so, please comment with a citation. I’m not aware of one.

The more controversial statement is that most theists are agnostics. Certainly, some theists would claim that they know with 100% certainty that God exists. But I wonder if they would maintain that view if they thought about it for a moment. The only way that we can be 100% certain about any proposition’s truth is that the proposition is necessarily true or necessarily false. If God is said to exist necessarily, that means that it is logically impossible for God not to exist, that God exists in all possible worlds. We cannot be 100% certain about the existence of any object of human experience, because it is always possible, however unlikely, that our experience is mistaken. But logical necessities are true by definition, i.e., features of human grammar, not entities, not objects of human experience. However, theists believe that God is an object of human experience, an entity, not a feature of human grammar. Therefore, God cannot be a logical necessity (this is the reason why the ontological argument doesn’t work). It is therefore possible, indeed plausible, that most theists realize that they can never be 100% certain of God’s existence, and therefore that they accept agnosticism. Now, some theists will probably reject the premise that human experience is fallible. They may assert that some type of human experience, such as faith, is infallible and can therefore generate 100% certainty. This claim, of course, is impossible either to prove or to refute. So I cannot claim that all theists would, on reflection, accept agnosticism as defined here, but I think that most would.

So “agnosticism” doesn’t seem to be a very useful category, if it can encompass atheists and theists. Is there another definition of the term that would be more useful? According to Wikipedia, here are some other definitions of agnosticism:

“Agnosticism is not a creed but a method, the essence of which lies in the vigorous application of a single principle… Positively the principle may be expressed as in matters of intellect, do not pretend conclusions are certain that are not demonstrated or demonstrable.” -Thomas Henry Huxley

Well, again, who would disagree with that, besides hardcore fideists?

“Agnostic atheists are atheistic because they do not have belief in the existence of any deity, and agnostic because they do not claim to know that a deity does not exist.”

Again, I know of no atheist who would not be agnostic by this definition.

“Agnostic theism – The view of those who do not claim to know of the existence of any deity, but still believe in such an existence.”

Again, how many theists would really disagree with this, if “know” means “know with 100% certainty”?

“Ignosticism – The view that a coherent definition of a deity must be put forward before the question of the existence of a deity can be meaningfully discussed. If the chosen definition is not coherent, the ignostic holds the noncognitivist view that the existence of a deity is meaningless or empirically untestable.[19] A.J. Ayer, Theodore Drange, and other philosophers see both atheism and agnosticism as incompatible with ignosticism on the grounds that atheism and agnosticism accept ‘a deity exists’ as a meaningful proposition which can be argued for or against.”

If these guys are professional philosophers, this must be a total bastardization of their claims. The claim that “at least one entity not bound by natural laws exists” is obviously not logically impossible. It’s not self-contradictory. There may be some definitions of deities that are self-contradictory, like “a deity is a square triangle,” but to show that meaningless claims about meaningless entities are necessarily false is not to prove that no supernatural entity in the aforementioned sense exists.

“Strong agnosticism – The view that the question of the existence or nonexistence of a deity or deities, and the nature of ultimate reality is unknowable by reason of our natural inability to verify any experience with anything but another subjective experience. A strong agnostic would say, ‘I cannot know whether a deity exists or not, and neither can you.'”

Again, if “know” means “know with certainty,” who would disagree with this? We’re all (almost all) strong agnostics about everything.

“Weak agnosticism – The view that the existence or nonexistence of any deities is currently unknown but is not necessarily unknowable; therefore, one will withhold judgment until/if any evidence is available. A weak agnostic would say, ‘I don’t know whether any deities exist or not, but maybe one day, when there is evidence, we can find something out.'”

If “know” means “know with 100% certainty,” then this claim seems obviously wrong. I’ll never be able to know with 100% certainty whether any other human beings exist; what evidence could possibly make me 100% certain that a supernatural entity exists?

But maybe “know” in some of these definitions simply means “be able to assign some probability value whatsoever to the proposition that.” But since supernatural entities are potential objects of human experience, we should be able to assign some probability to their existence, even if we believe we have no experience of them whatsoever. We can at least venture a guess with a very wide confidence interval. Then as more evidence comes in, we can improve the quality of our guess. The strong version of this form of agnosticism doesn’t seem to make sense either, because it does not seem possible for anyone to know with 100% certainty that there will never be any evidence either for or against the existence of supernatural entities.

In the end, I don’t understand how agnosticism isn’t either obviously true and therefore uninteresting or almost incoherent. I should like to abolish the term from philosophy of religion altogether.