Concept

Category Error

Intro

A category error is treating something as if it belonged to a kind it does not belong to, then asking a question that only makes sense for that other kind. "What color is the number seven?" is a category error: numbers are not the kind of thing that has a color. "How much does Tuesday weigh?" is another.

A category distinction is the opposite move done correctly: noticing that two things are different kinds of thing, so that rules for one do not automatically apply to the other.

Christians often say that "Who created God?" is a category error, because it treats the uncreated source of everything as one more created thing. That reply is sound, but only if the distinction behind it can be shown and not just announced. A category distinction is a claim, and a claim needs support.

The Radcliffe Camera, a domed library building at the University of Oxford, in evening sunlight

The Radcliffe Camera, Oxford. Gilbert Ryle's famous example of a category mistake is a visitor shown Oxford's colleges and libraries who then asks, "But where is the University?" Photo: Mike Peel, CC BY-SA 4.0, via Wikimedia Commons, resized.

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In full

The term category mistake was made famous by the Oxford philosopher Gilbert Ryle in The Concept of Mind (1949). His example is a visitor to Oxford who is shown the colleges, libraries and laboratories and then asks where the University is, as if it were one more building alongside them rather than the way they are organized. The mistake is not a false belief about a building. It is a misplaced question.

Three terms need to be kept apart:

Term	What it does	Example
Category distinction	Identifies that two things differ in kind, not just in their features	A number and a stone are different kinds of thing
Category error	Applies a property or question proper to one kind to something of another kind	"What does the number seven weigh?"
Special pleading	Exempts one case from a rule without a reason	"Everyone must pay tax, except my friends"

A legitimate category distinction and special pleading can look alike, because both exempt something from a rule. The difference is the reason. A category distinction names the property that puts the thing outside the rule's scope. Special pleading names none. See Special Pleading.

The justification requirement

A category distinction is only as good as the properties that mark it. Before calling an objection a category error, three questions have to be answered:

What exactly does the rule cover? State the rule in its real scope, not a careless version of it.
What property places the thing outside that scope? Name a feature that can be checked.
Does the thing actually lack that property, and on what grounds? Show it, or at least point to the argument that shows it.

Worked example: "Who created God?"

The rule: whatever begins to exist, or depends on something else for its existence, has a cause.
The property: beginning, being composed of parts, changing, receiving existence from another.
The grounds: God, as classical theism understands Him, did not begin (Psalm 90:2), has no parts (Divine Simplicity), does not change (Actus Purus), and does not receive existence (Ipsum Esse Subsistens). Whether such a being exists is a separate question, settled by the cosmological arguments, not by the definition.

See Who Created God Objection Defeater.

Use and misuse in apologetics

Legitimate uses:

"Who created God?" The causal principle covers dependent things; God is not one.
"Where in the brain is the thought?" A thought's meaning may not be the kind of thing that has a location, even if its physical basis does. See Argument from Consciousness.
"Science has found no evidence of God in the universe." God is not proposed as an object within the universe, so not finding Him among its objects is what both sides should expect.

Misuses to avoid:

Calling every hard question a category error. If no property is named, the reply is special pleading wearing a better coat.
Defining God out of every objection. A definition can show an objection misfires. It cannot show that what is defined exists.
Ignoring the objector's real point. Often "who made God?" is a confused way of asking "why accept a first cause at all?" Answer that question too.

A good question to put to anyone claiming a category distinction, a Christian included: "What is the basis for placing these two things in different categories, and how have you shown it rather than assumed it?"

Scholarship

Published academic works this page draws on, each matched to a publisher, index or library catalog record.

Gilbert Ryle, The concept of mind (1949). Open Library

Common questions this page answers

Q: What is a category error?

A category error treats something as belonging to a kind it does not belong to, then asks a question that only fits that other kind. Asking what color the number seven is, or where the University of Oxford is after being shown all its colleges, are classic examples.

Q: What is the difference between a category distinction and special pleading?

Both exempt something from a rule, but a category distinction gives a reason: it names a property that places the thing outside the rule's scope. Special pleading makes the exception without a reason.

Q: Is "Who created God?" a category error?

It is when aimed at the God of classical theism. The causal principle covers things that begin or depend on others, and God is understood as neither. That reply shows the objection misfires, but it does not by itself prove God exists; the cosmological arguments do that work.

Q: Who coined the term category mistake?

The Oxford philosopher Gilbert Ryle made the term famous in The Concept of Mind (1949), using the example of a visitor who sees all of Oxford's colleges and libraries and then asks where the University is.