I am sometimes confronted by religious zealots (some of whom knock on my door). Typically what follows is a fruitless discussion along these lines: How do you know what you’re saying is true? Because it says so in my holy book. And how do you know that what is in your holy book is true? Because it is the word of God. How do you know it is the word of God? Because it says so right in the book. But how do you know the book is true? etc. etc. etc.
A similar impasse results when I’m confronted by atheists: How do you know there is no God? Because [holy book in question] is inconsistent. So, maybe God is not the way God is depicted in any holy book. If God exists, why is there suffering in the world? Perhaps God works in mysterious ways, for some deeper purpose that you don’t see. That makes absolutely no sense to me. So, just because it makes no sense to you doesn’t mean it’s impossible. Belief in a God inevitably leads to irrational contradictions. I have no need of that hypothesis. etc. etc. etc.
It seems that my conversations with extremists of both types are pointless. And which type am I? Well, there are three types of people in the world: Those who can count, and those who can’t. (Evidently, I’m the third type.)
At some point during these pointless arguments, my interlocutor typically asks me how I know that my beliefs are true, to which I instantly admit that I don’t know that my beliefs are true. I recognize that they are part of the human condition, that we all need beliefs in order to function, but that I don’t take them so seriously. I would certainly never harass someone or think less of someone just because their beliefs are different from mine.
Now it is quite possible to be religious, to believe in God, and still be a scientist, as quite a number of scientists have shown, both in the past and in the present. However, if you wish to literally believe what is in some holy book or other, and still do science, then you may have a problem (depending on what exactly the holy book says).
However, the Intelligent Design movement (formerly called Creationism) is definitely unscientific. They begin with the certainty that their holy book is correct, and that the God portrayed in that holy book certainly exists. Then they search the scientific literature for just the evidence that supports their pre-existing certainties. This is not how science works.
To be scientific, you carefully examine all of the evidence, and provisionally accept what can be concluded from all of the evidence once you apply reasoning to it. You don’t begin with pre-existing certainties. Certainty is the death of scientific progress, because where there is certainty, there is no change. But the growth of scientific understanding and insight requires changes of some sort: Changes in our ideas, in our perspectives, in our cherished beliefs. Science is like a giant work of art, constantly being revised by the toil of a grand collective of artists, artisans, and crafts people.
There is a lovely Zen story that illustrates this point (you can find it in many places on the internet; for example, here):
Nan-in, a Japanese master during the Meiji era (1868-1912), received a university professor who came to inquire about Zen.
Nan-in served tea. He poured his visitor’s cup full, and then kept on pouring.
The professor watched the overflow until he no longer could restrain himself. “It is overfull. No more will go in!”
“Like this cup,” Nan-in said, “you are full of your own opinions and speculations. How can I show you Zen unless you first empty your cup?”
* * *
It’s part of human nature to be attracted to certainty; it’s comforting, isn’t it? And who doesn’t desire some sort of reassurance in the face of the fearsome world that we live in. But let’s be sure to recognize this tendency for what it is: a fearful part of human nature that all of us are subject to.
Awareness is key. If we are aware of our fearful nature, and can recognize when we are being fearful, then we have a hope of maintaining our equilibrium when smooth talkers try to sway us by appealing to our fears.
And don’t kid yourself: The truly great among us have fears just as we do. They just have greater courage, so they are able to operate in spite of their fears, whereas most of us are paralyzed by our fears. Their reward is to tame those fears (perhaps), but others arise!
And don’t kid yourself: The smooth talkers who would be our leaders have their doubts, too, but they assuage their doubts by convincing us! They figure if they can convince enough people, if enough people join them in their beliefs, then maybe they are right after all! But the doubts are always there, somewhere lurking beneath, no matter how hard we work to bury them.
As they should be, for without doubt, what would be the need for faith?
It’s comforting to allay our fears by bathing in the warm waters of certainty; it takes courage to walk outside in the chilling storm of doubts. But the latter is essential for growth.
Doubt is not a pleasant condition, but certainty is an absurd one.
— Voltaire, Letter to Frederick the Great, 6 April 1767 (as quoted on page 179 of Dictionary of Quotations, edited by Bergen Evans, Avenel Books, 1978)