Naturalism can describe what you believe. It cannot tell you what you owe.
It is the line that ends the conversation. Said with a certain calm, usually leaning back: I just follow the evidence wherever it leads.
It sounds like humility. It is meant to. And notice that it is not, in fact, a scientific claim. It is a claim about how a person ought to behave — that you have a duty to proportion belief to evidence, that wishful thinking is a failure and not merely a strategy, that a man who believes what is comfortable rather than what is supported has done something wrong.
I agree with every word of that. Completely. Intellectual honesty is a real obligation and the person who breaks it has done real wrong.
The question is simpler than it looks, and I have never heard a naturalist answer it: on your account of reality, where did that obligation come from?
Separate the two questions carefully
This is not the old argument about whether your brain can be trusted. That is a different line of attack — that if the mind is the unguided output of survival pressure, its conclusions are suspect. It has been argued well and argued often, and it is not what is on the table here.
Grant, for the sake of argument, everything the naturalist wants on that front. Say the brain is a beautifully reliable instrument, tuned by selection to track reality with precision. Fine. Suppose it works perfectly.
A reliable instrument still tells you nothing about what you are required to do with it. A thermometer is reliable. It generates no duty to read it. You can have a mind that perfectly tracks truth and no reason on earth why you should be honest with what it hands you.
That is the gap. Not can I know? but why must I care? Naturalism is an account of what exists and how it behaves. The demand to follow the evidence is not a description of behavior. It is an imperative. It says a man who does otherwise is culpable — not unlucky, not maladaptive, but guilty.
The three answers, and where each one runs out
There are essentially three moves available, and it is worth taking each one seriously rather than waving at it.
One: it is useful. Tracking truth keeps you alive. Believing there is no tiger gets you eaten.
True, and irrelevant to the point. Usefulness generates a conditional, not a duty: if you want to survive, track the tiger. But the evidentialist is not saying “follow the evidence if it suits your goals.” He is saying follow it even when it costs you everything — even when the honest conclusion wrecks your career, your marriage, your standing in the department. That is precisely the case where usefulness has stopped recommending it. The imperative is strongest exactly where the usefulness is gone, which means usefulness was never what was holding it up.
Two: it is what we have agreed. Intellectual honesty is a social norm, like queueing. Communities that adopt it flourish.
Then it binds no one who has not agreed, and it binds no one in private. A researcher who quietly shapes his data and is never caught has violated a convention he did not sign, in a room with nobody in it. If honesty is merely conventional, we have no grounds to call that wrong — only against local custom. Yet every one of us knows it is wrong, and knows it the same way in Cambridge and in Cairo. A convention that everyone treats as non-negotiable in every culture is doing more work than a convention can do.
Three: it is a preference and we should stop calling it a duty. This is the most consistent answer, and I respect it most.
But watch the cost. Take that road and you may no longer say the believer is irrational in any blaming sense, or intellectually dishonest, or that he should examine his assumptions. You have given up the entire vocabulary the argument was being conducted in. You can say religious belief is not to your taste. You cannot say it is a failure of duty, because on your account nobody has one.
Where an obligation has to come from
Obligations are strange things. Facts about matter describe how things are. An obligation says how a person must be, and it holds whether or not he feels it, whether or not anyone is watching, and whether or not it profits him.
Every obligation we can actually trace runs back to a person with the standing to impose it. A contract binds because parties bound themselves. A law binds because a legislature had authority. There is no example anywhere of a real duty arising out of impersonal material with no one behind it, because duty is the kind of thing that is owed, and owing is between persons.
So when a man says he is obligated to the truth, he has said more than he knows. He has reported an encounter with an authority he has not named.
For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: which shew the work of the law written in their hearts, their conscience also bearing witness. (Romans 2:14–15, KJV)
Paul is not saying unbelievers have no morals. He is saying the opposite, and saying it as evidence. They have them, they did not manufacture them, and their own conscience keeps testifying to a standard they never legislated.
What this argument does not prove
Let me fence this in honestly, because overclaiming here would be its own violation of the duty under discussion.
This does not prove that atheists are dishonest. Many are scrupulously honest, often more so than professing Christians, and that is exactly what the argument predicts — the standard is written on every man, believer or not.
It does not prove the Christian God by itself. It gets you to a personal source of moral authority. Getting from there to the God of Scripture requires the rest of the case — the resurrection, the prophets, the Book.
And it is not a gotcha to be deployed for the pleasure of watching someone stall. It is an invitation to notice something you are already standing on.
The confrontation
Because here is the sharp end of it. The man who says follow the evidence wherever it leads has committed himself to a principle that may lead somewhere he has already decided not to go.
If the rule is real, it applies to the question of God like it applies to anything else. It does not permit deciding in advance that only certain answers are admissible and then calling the result open inquiry. A commitment to follow the evidence that quietly excludes one conclusion before the counting starts is not a commitment. It is a preference in a lab coat.
For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness. (Romans 1:18, KJV)
“Hold” there means hold down — suppress, keep under. Paul’s charge is not ignorance. It is a man pressing down on something he already has. And that is a charge no naturalist can bring against anyone, since on his own account there is nothing anyone is obliged to do with the truth in the first place.
How to use this in an actual conversation
- Agree first, and mean it. “You are right that we ought to follow the evidence. I hold that too.”
- Ask the one question. “Where does the ought in that sentence come from?” Then stop talking and let him work.
- Do not treat a pause as a win. He is thinking about something he has probably never been asked. That is a good thing happening, not a point scored.
- Follow with the honest version: “I am not saying you are dishonest. I am saying you are more honest than your worldview can pay for.”
The reason the duty is real
You feel obligated to the truth because you were made by One who is true, in His image, and He wrote that obligation into you before you had an opinion about Him. That is why it will not go away when it is inconvenient, and why no amount of philosophy talks a man out of it at three in the morning.
And the truth you are obligated to is not finally a proposition. It is a Person, who said it about Himself in the plainest words available:
Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. (John 14:6, KJV)
So follow the evidence wherever it leads. Genuinely. All the way, with nothing ruled out at the start.
The thing doing the leading has a name.
Teaching the Word. Watching the Times.
— SmithForChrist