If it is impossible to prove a negative why do some atheists make the claim God does not exist?

Answer 1

That's a very good question. I'd like to say those that are educated/learned in debate, logic etc. would not claim so, and would be agnostic atheists, who do not claim to know of God's lack of existence but are convinced as such, as opposed to gnostic atheists, whom you describe. From conversations with them they appear to be so utterly convinced that they decide it isn't possible. And I see what they mean, but they should learn to leave that tiny percent of doubt, in the interest of rationale. Those atheists such as myself who are agnostic atheists but very 'hardcore' often use the analogy of 'a-teapotists', as Richard Dawkins coined I believe. This is about not being able to disprove that a teapot is orbiting Saturn, but the chance is still there so we must be inclusive. Gnostic atheists don't care about this and go over the line, saying he doesn't exist, period. It is basically an irrational position, but better that than being religious, in my humble opinion.

Answer 2

Atheists are people and so they do not all think with one mind. An atheist may make that claim through observation of the human condition. If you want to know why someone thinks something then you need to ask that person that question. You should note that atheists as a group are not as concerned with questions of gods as much as believers are concerned with the non-belief of atheists.

Answer 3

Atheists say there is no evidence that God exists. This statement is demonstrably true.

Richard Dawkins, perhaps the most famous contemporary atheist, has said, "God probably does not exist." This statement is more moderate and rational than the common Christian assertion that God certainly exists.

Answer 4

They may use as evidence such things as human suffering, or evolution. Neither of these disprove God, but some people may think that they do. See also:

Is there evidence for God?

Answer 5

There are two different claims that are generally made by different groups of Atheists and these are worth distinguishing because they require different evidential standards.

Argument 1: Null Hypothesis: There are Atheists who argue, correctly, that the proper assumption to start off any argument is that whatever is being proposed to exist does not actually exist until evidence is shown to defend this proposition. This argument is called the null hypothesis, i.e. there is nothing until shown otherwise. This is the position taken most clearly by Atheist Advocate Matt Dillahunty.

For example, if I tell you that I own a boat, the proper beginning position is for you to disbelieve me until I show you evidence (such as a receipt from when I bought the boat, pictures of the boat, or we go down to the docks together and I show you the boat). You then decide if the evidence that I have provided to you is sufficient to meet your standard of acceptability for my proposition. These Atheists argue that God is the same way; when they are told that God exists, they demand evidence in order to convince them that God exists. When Believers present their pieces of evidence (holy books, miracles, etc.), these Atheists argue that these pieces of evidence are insufficient to meet their standard of acceptability.

Argument 2: Guilty of Not Existing: There are Atheists who argue that there is sufficient evidence to argue that God actually does not exist. This is different than the Null Hypothesis since (1) this is a conclusion and (2) makes a claim about material reality. The argument is that even if 100% certainty is impossible, it is beyond a reasonable doubt that God does not exist. This is the position taken most clearly by Geneticist Richard Dawkins.

If we go back to the "my boat" example from the Null Hypothesis Argument, the issue here is that you would say that after I presented you all my pieces of evidence that I own a boat, you present far more evidence that I do not actually own "my boat". Perhaps you show that the pictures I showed you were stock photos, the boat I showed you was registered to someone else, the receipt I showed you referred to a boat that I had since sold to another person AND you have discovered that I am a con-man who often deceives people into believing he has a boat. You are now inclined to actually believe that I have no boat since there is more evidence against the proposition I have a boat than for it. As a result, these Atheists argue that the evidence AGAINST the proposition is sufficient to meet their standard of acceptability and argue that the claim that God exists is definitively false.

Answer 6

While it seems hard, perhaps impossible, to either prove or disprove the existence of God, that doesn't mean you can't prove a negative in general.