David Hume, an 18th century Scottish philosopher is one of the most influential empirical philosophers. Empiricism is the idea that knowledge comes from experience, so for Hume, the only we can know something is through some form of experience. He once wrote that:
“the wise man proportions his belief to the evidence.”
By this he meant that the strength of our belief about an experience should be in proportion to the evidence we have. So, for example, we see the sunrise every morning. We feel its effects all around us, so we have lots of strong evidence to indicate that the sun does rise every morning, so our belief that the sun rises every morning should be in proportion, that is, we have a strong belief. We would say that we know the sun rises every morning.
But what about a belief where the evidence is not as strong. Imagine having a belief that you saw a UFO last night. This is the only time you have seen such a thing and it was way up in the sky. Here we have very limited amounts of evidence and so Hume says the wise thing to do is proportion our belief to the evidence, so we would hold the belief weakly. We would probably say we were unsure. Hume is not saying we are wrong to believe it, just that we should only believe it in proportion the evidence we have. We should always seek to weigh up the evidence we have and come to a appropriate conclusion.
In his book, Dialogues Concerning Natural Religion, Hume writes about miracles, but what he says can be applied to religious experience generally.
When faced with miracle account, or any other account of religious experience, Hume wants us to weigh up the evidence for an against the claim and this will tell us what the rational thing to believe is.
So, on the one hand, what is the evidence that people really do have experiences of God?
Clearly, as we have seen, there are accounts of religious experiences: Moses, Saul, Muhammad, St. Teresa of Avila, St. Bernadette and so on. So we do have some evidence, but there aren’t many of the these accounts and as we already know, none of these really strongly demonstrate the existence of God. This evidence can be placed on one side of the weighing scales that Hume suggests we use.
But what of the other side? Hume suggests a series of questions that ask us to look at the evidence against these claims being true. For example, how much evidence do we have of people being mistaken or of people having been deceived? How often do we find that people tell lies, maybe out of spite, to seek attention? How often do we find people have embellished and exaggerated? How often are people confused, having misunderstood something?
Hume claims that we have lots of evidence of these, and so when weighed against the possibility of these religious experiences being genuine, he claims it is always more likely that it is not true; that there is a more likely alternative explanation.
When we weigh up the evidence in order to proportion our belief, we should accept the more likely, the one with the weight of evidence and reject the less likely. We should accept the more probably and reject the more improbable.
And Hume’s claim is that the evidence tells us to reject the idea that religious experiences are genuine and veridical. For Hume, there is always a more likely explanation that these experiences are genuine. It is always more probable that there is an alternative explanation.
If our key question is Are religious experiences really of God, Hume would say that most probably answer, the wisest answer is a clear No.