It’s widely acknowledged that it isn’t possible to prove absolutely
that no gods exist, any more than it’s impossible to prove absolutely
that no invisible unicorns exist. Every atheist I know freely
acknowledges that. But at the same time, one can easily argue that
gods (or invisible unicorns) are very unlikely to exist.
A lot of these arguments are meta-arguments, in that they don’t stand
on their own, but build upon arguments made by theists.
Lack of evidence
Despite what a lot of people think, atheism isn’t the firm belief that
there aren’t any gods. Rather, it’s a lack of belief in gods.
To put it another way, the atheist position is “You believers haven’t
made your case. I’m not convinced that you’re right.”
So the lack of evidence is the big one. There is no good evidence for
any gods. No verified miracles, no verified prophecies, no burning
bushes, no nothing.
There’s a saying that “absence of evidence is not evidence of
absence”. This is true as far as it goes, but absence of evidence
where we would expect to see some is evidence of absence.
If I say that there’s a Thai restaurant at 15th and K, the fact that
you’ve never heard of it doesn’t mean that I’m wrong. If, however, you
go down to 15th and K, and look all over, and fail to find the Thai
restaurant, that is good evidence that I’m wrong.
Theists have had thousands of years to demonstrate that their various
gods are real. And they’ve tried. Oh, boy, have they tried. And so
far, bupkis. No divine abodes on top of Mount Olympus, no rainbow
bridge to Asgard, no Noah’s Ark, no nothing.
Okay, so maybe gods aren’t directly detectable, either with our senses
or simple measurement devices. Maybe they don’t reflect visible light,
or emit sound waves, or pull compass needles toward them. That still
leaves indirect evidence.
I’ve seen satellite photos in which you couldn’t see ships, but you
could see their wakes. A lot of extrasolar planets have been
discovered not by direct observation, but by they affect the orbit of
their sun. Heck, if it comes to that, all nuclear physics is done
through indirect observation: protons and electrons are too small to
see, but we can observe the shape of trails in a bubble chamber, or
flashes of light on a CRT.
It’s not just the so-called hard sciences, either: there are
statistical methods for figuring out whether an election was rigged by
looking for anomalies in the results, the sorts of things that would
be introduced by a cheater, but unlikely to come up by chance.
And yet, nothing. No good direct evidence, no good indirect evidence.
The Templeton Foundation keeps throwing money at trying to come up
with evidence of a god — studies on intercessory prayer, that
sort of thing — and so far they’ve come up with two kinds of
results: ones that come from flawed experiments, and ones that show no
I don’t think it’s just me being overly skeptical: after 2000 years,
Christians have still failed to convince two thirds of the world’s
population that they’re right. Jews and Hindus have had even longer.
Miracles of Islam
are not convincing to anyone but Muslims. And so on, and so forth.