A common argument made by religious apologists is that atheism is unreasonable because, to exclude the possibility of God, a person would have to have total knowledge of all that exists in the universe. Otherwise, we might overlook a deity hiding in one of the gaps in our knowledge. As one Christian put it to me in an e-mail:
And certainly, unless you have visited an appreciable portion of the cosmos and whatever else, there is at least a reasonable possibility that a creator exists. In other words, as small creatures on this planet (proud of ourselves as we are) we are not in a position to materially discount the existence of a creator.
This argument has the burden of proof backwards, for reasons I explained in last year’s post “How to Think Critically IV“. The point here is that evidence is the link to truth; no person is justified in making an existence claim unless they have specific evidence in favor of the entity they believe in. If they can’t present any such evidence, then the rest of us can justifiably dismiss that claim as without foundation. For obvious reasons, we’re not obligated to search the entire universe every time someone comes up with a crackpot idea in order to prove them wrong!
This is exactly the situation with atheists. No atheist I know of has searched the cosmos top to bottom to disprove the existence of God, nor do we need to. We can simply point out that all the gods put forth by human claimants so far lack persuasive evidence in support of their existence. (We can also take this one step farther by pointing out that we observe evidence inconsistent with the claimed desires and abilities of many of these gods.) Until and unless better evidence turns up, we are fully justified in considering these claims to be unconnected to objective reality, and refusing to believe them on that basis.
Still, it’s true that the universe is a big place, and it’s equally true that we humans know, at most, a tiny fraction of all there is to know about it. Are we atheists, therefore, being too hasty to dismiss the possibility of God? There might be something out there, something that vindicates the theologians. Knowing as little as we know, shouldn’t we consider that possibility at least as likely as the alternative?
I don’t believe so. In fact, I believe that the vastness of the cosmos, and our limited ability to understand it, can actually be understood as an argument not for theism, but for atheism. Allow me to explain.
It’s quite true that human beings’ knowledge of the universe is painfully limited. Our history testifies to this. The path of intellectual progress is littered with the discarded rubbish of false ideas: the heliogeocentric solar system, alchemy, spontaneous generation, the miasma theory of disease, phlogiston, Lamarckian evolution, bleeding as medical treatment, the luminiferous ether, and countless more. All these ideas were once believed – often widely believed, and fervently defended – but ultimately, empirical testing proved them to be false. The few grains of truth that we have managed to glean about the cosmos were acquired only through painstaking research, and even those are tentative and provisional, liable to be overturned tomorrow, in principle, if we find the right evidence.
The universe does not work the way we expect. Countless people have relied on “common sense”, or declared some truth “obvious”, only to be subsequently proven wrong. Our minds work well to deal with phenomena on the scales of distance and time we experience every day, but, unaided, they are inadequate to directly perceive the ultimate underlying truths of reality. On the contrary, it seems that the universe reveals its true nature only through diligent investigation, and usually only after hundreds of hypotheses have been tested and rejected. All of this should be beyond dispute.
But the origins of all modern religions did not come about in the present. They first appeared among people and cultures in the distant past, centuries or even millennia ago, when even the most basic scientific understanding of the world was absent and superstitions of all kinds ran wild. Should we be willing to believe that people who knew so little compared to us nevertheless managed to see so far ahead of us?
This is extremely implausible, and that’s precisely why we’re skeptical of the claims of religion. We are skeptical that an ancient, primitive tribe, with no notion of science and whose beliefs about many other things we now know to be rank superstition, managed to penetrate the most profound secrets of the universe. If the need for intellectual humility applies to us, still more should it apply to them. If we have little enough reason to think that we know the most profound truths of the cosmos, still less do we have reason to think that those who were so much less advanced than us knew them.
And what should compound our skepticism is that the belief in God held by ancient peoples is so much like many other ideas which they held and which we now know to be false. Human beings have a natural tendency to anthropomorphize phenomena they do not understand, leading them to imagine supernatural gods, angels and spirits who caused weather, disease, life and death, and many other natural events. Today we understand the real causes of many of these things, and the supernatural agents once thought to cause them have faded away, but the belief in a creator-god persists. If we take past history as a guide, isn’t it most reasonable to assume that this belief, too, will eventually vanish as we discover ultimate causes, no less than all other causes, to be natural?