Materialism says nothing is for anything. Then it hands you a textbook that cannot be written without the word.
Open any undergraduate biology text and start underlining. The ribosome reads the message. DNA codes for a protein. The kidney’s job is filtration. The immune system defends. Mitochondria are for energy. Chlorophyll’s purpose is to capture light. By the end of one chapter the page is covered in ink.
Now read the book’s own philosophy, usually tucked into the introduction: purpose in nature is an appearance only. There are no ends, no goals, no intentions anywhere in biology. Living things merely look designed because unguided variation and differential survival produced them.
So which is it? Either the purpose language is doing real work — in which case the official philosophy is false — or it is a four-hundred-year-old figure of speech that the discipline somehow cannot do its work without. That is not a gotcha. It is one of the most interesting unresolved problems in the philosophy of biology, and it is worth walking through honestly.
Function talk is not decoration. It is the instrument.
Consider how a discovery actually happens. A researcher finds an unfamiliar protein and asks one question first: what does this do? Not what is its history — what is it for. The entire research program of molecular biology is reverse engineering, and reverse engineering is the study of purposes.
Medicine makes it unavoidable. The phrase heart failure is a judgment, not a description. Failure presumes the heart was supposed to be doing something it is no longer doing. A rock cannot fail. A river cannot malfunction. Only a thing with a function can break — and a doctor who does not believe in function has nothing to treat, only molecules rearranging themselves in a pattern he happens to dislike.
You cannot have pathology without normality. You cannot have a defect without a design. The vocabulary of every clinic on earth is teleological, and no one has found a way to translate it out.
The strongest naturalist answer — and why it falls short
Naturalism has a serious reply here, and it deserves to be stated at full strength rather than caricatured. It is usually called the selected-effects account of function, and it goes like this: to say the heart is for pumping blood just means that pumping blood is the effect for which hearts were historically favored by natural selection. Purpose is cashed out entirely in past causes. No designer required, no goals in the present, and the word for survives as legitimate shorthand for a long causal history.
That is a genuine achievement, and any Christian who pretends it is nonsense is not arguing fairly. But it carries three weights it cannot lift.
- It converts an ought into a was. A history of frequencies tells you what happened. It cannot tell you what anything is supposed to do. On this account, “your kidney is malfunctioning” means only “your kidney is doing something different from what ancestral kidneys were selected for” — which is a statistical remark about dead organisms, not a standard your kidney is answerable to. Yet every physician treats it as a standard, and so do you when you go in.
- It cannot handle the new. A structure co-opted for a use it was never selected for — a bone repurposed, a protein doing a second job — has a function right now, on its first day, before selection has had any opportunity to favor it. Biologists describe that function confidently. The historical account cannot supply it.
- It explains purpose by assuming survival matters. Selection favors what aids survival and reproduction. But aids is already a purpose word. Why does survival count as success rather than as merely one more thing that occurs? The account smuggles in a goal — staying alive and reproducing — and then congratulates itself for deriving goals from goalless matter.
It is worth noting that some of the sharpest pressure here has come from inside the camp. Thomas Nagel, an atheist philosopher with no theological axe to grind, has argued publicly that the standard materialist picture is very likely incomplete precisely because it cannot accommodate mind and purpose, and he took considerable abuse from his own side for saying so. This is not a believer’s talking point. It is a live fault line.
A machine in a field
Imagine you find an unfamiliar machine in a field. You can map every gear, trace every weld, and reconstruct the whole history of its manufacture — which plant, which year, which hands. You will still not know what it is for until you know what somebody meant by it. Purpose is not a property you can read off of matter. It is a property that arrives with intent, and nowhere else.
Which is why the biology textbook reads the way it does. Researchers are not being sloppy. They are describing what they find, and what they find behaves exactly like equipment with assignments.
Scripture puts purpose in the first chapter and never takes it out
The biblical account does not merely permit function language. It opens with it.
And God said, Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs, and for seasons, and for days, and years.
— Genesis 1:14 (KJV)
Four uses of for in a single verse, on day four, before a single creature exists to be selected. Purpose is not a late arrival in the biblical universe; it is in the specification. And when Proverbs touches the body, it says the same thing with no hedging.
The hearing ear, and the seeing eye, the LORD hath made even both of them.
— Proverbs 20:12 (KJV)
Observe the phrasing. Not “the ear and the eye,” but the hearing ear and the seeing eye — the organ named together with its office. Scripture cannot describe the thing without naming what it is for, which is precisely the habit the textbook cannot break either.
For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him.
— Colossians 1:16 (KJV)
There is the ground. Purpose runs through creation because creation was made for Someone. Take that clause out and the word has no floor to stand on — which is exactly the position naturalism finds itself in, borrowing a vocabulary it has formally renounced.
The part that is not academic
Follow the doctrine down to where you live. If nothing in nature is for anything, then you are not for anything either. You are a local arrangement of matter with a history and no assignment. On that view the question men ask in the dark — what am I here for? — is not a hard question. It is a malformed one, like asking what the number seven smells like.
Here is the tell: nobody can live there. The same person who says purpose is an illusion will grieve a wasted life, resent a job that squanders him, demand that his work matter, and take his child to a doctor to have a function restored. He is not being stupid. He is being human — which is to say he is behaving like a creature who knows at some level that he was made on purpose and is accountable for what he does with it.
That is the apologetic. Not that materialists are fools, but that materialism cannot be inhabited. It must be set aside every time a man goes to work, loves his wife, mourns his father, or calls anything broken.
What you were made for
The Bible will not leave the question where philosophy leaves it. It answers it.
Thou art worthy, O Lord, to receive glory and honour and power: for thou hast created all things, and for thy pleasure they are and were created.
— Revelation 4:11 (KJV)
And the gospel is function restored. Sin is not merely rule-breaking; it is a creature running against the purpose it was made for, which is why it produces the exhaustion it produces. Redemption is not God improving a machine that was always pointless. It is the Maker reclaiming equipment He designed, repairing what failed, and putting it back to its original office.
So the next time someone tells you science has retired purpose, ask him one question, kindly: then what is a kidney for? He will answer. He cannot help it. And the answer he gives — effortless, confident, obviously true — is a word his worldview cannot pay for and yours can.
Teaching the Word. Watching the Times.
— SmithForChrist