What Is the Redundancy Theory of Truth?

What Is the Redundancy Theory of Truth?

The redundancy theory of truth holds that the word "true" is redundant. When you say "it is true that snow is white," you are saying nothing more than "snow is white." The truth predicate — the phrase "it is true that" — adds nothing to the content of the assertion. It is a stylistic variation, a device for emphasis or endorsement, but not a marker of a real property.

This is a striking claim. Most people assume that truth is something — a property that some beliefs have and others lack. The redundancy theory says this assumption is mistaken. Truth is not a property; it is a word that we use for certain practical purposes, and those purposes do not require it to name anything real.

The theory is the earliest and simplest form of deflationism about truth — the family of views that hold truth is not a deep or substantive concept. Later deflationists (Horwich, Quine, Grover) developed more sophisticated versions to handle cases that simple redundancy could not, but the core insight traces back to Ramsey: truth is thin, not thick.

Historical Background

The Problem of Truth

The philosophical problem of truth is ancient. Plato and Aristotle debated whether truth is correspondence to reality. The Stoics connected truth to the disciplined examination of impressions. Medieval philosophers developed sophisticated theories of veritas. In the modern period, correspondence, coherence, and pragmatist theories competed to explain what truth is.

All of these theories are inflationary: they hold that truth is a real property that needs explaining. The redundancy theory breaks with this tradition. It says that the question "what is truth?" is based on a false assumption — that truth is something that needs explaining. Truth is not a property at all; it is a linguistic device.

Ramsey's Innovation

Frank Plumpton Ramsey (1903–1930) was a British philosopher and mathematician who made extraordinary contributions in a short life. In his 1927 paper "Facts and Propositions," Ramsey argued that the predicate "is true" is redundant. His argument was based on careful attention to how the word "true" actually functions in language.

Ramsey observed that in simple cases, "it is true that P" is always equivalent to "P." "It is true that Caesar was murdered" means exactly "Caesar was murdered." "It is true that 2 + 2 = 4" means exactly "2 + 2 = 4." The truth predicate adds nothing. If this is always the case, then truth is not a property — it is a redundant expression.

Ramsey recognized that some uses of "true" are not straightforwardly redundant. "Everything he said is true" cannot be reduced to "everything he said" — the latter is incomplete. Ramsey proposed handling these cases through quantification: "for all p, if he asserted that p, then p." The truth predicate is replaced by a variable ranging over propositions. This is more complex than simple redundancy, but it preserves the insight that truth is not a substantive property.

Strawson's Performative Theory

P. F. Strawson (1919–2006) offered a variant of the redundancy theory in the 1940s and 1950s. Strawson argued that saying "that is true" is not a statement about a property of truth but a performative act — an act of endorsing, agreeing with, or conceding the statement in question.

On Strawson's view, when someone says "that is true," they are doing something — agreeing, confirming, endorsing — rather than describing something. The word "true" is performative, like "I promise" or "I apologize." It does not report a fact; it performs an act. This explains why the truth predicate feels substantive even though it does not name a property: the act of endorsement feels like asserting a fact, but the fact being asserted (if any) is just the original statement, not a further fact about its truth.

Strawson's performative theory handles cases that simple redundancy struggles with. "That is true" is not straightforwardly equivalent to any single assertion — it is an endorsement of whatever was said. The performative account explains this: "that is true" is an act of endorsement, not a redundant restatement.

Key Thinkers

F. P. Ramsey

Ramsey's contribution was to see that the truth predicate is eliminable in many of its uses. His argument was not that the word "true" is meaningless — he acknowledged that it has uses — but that its uses do not require it to name a property. The truth predicate is a convenience of language, not a marker of metaphysical reality.

Ramsey's approach was linguistic rather than metaphysical. He did not ask "what is the nature of truth?" but "how does the word 'true' function?" This linguistic approach was characteristic of the analytic philosophy of the early twentieth century, which turned from metaphysical speculation to the analysis of language.

Ramsey also recognized the challenge of propositional attitudes — beliefs, desires, fears that are directed at propositions. "John believes that it is raining" involves a proposition ("it is raining") that is the object of a belief. Ramsey argued that analyzing such cases does not require a substantive property of truth; it requires a careful account of how propositional attitudes relate to their propositional objects.

P. F. Strawson

Strawson's performative theory was a refinement of Ramsey's redundancy theory. Strawson agreed that truth is not a property but argued that the truth predicate is not merely redundant — it performs a specific function: endorsement. This performative function explains the pragmatics of truth — how the word "true" is used in conversation — without positing a metaphysical property.

Strawson was also a critic of the correspondence theory. He argued that the correspondence theory's central metaphor — truth as correspondence to facts — is misleading. Facts are not entities that statements correspond to; facts are just true statements. To say "it is a fact that snow is white" is to say "it is true that snow is white," which is to say "snow is white." The notion of a fact adds nothing.

Later Deflationists

Ramsey's redundancy theory faced challenges that led to the development of more sophisticated deflationist accounts:

• Horwich's minimalism holds that truth is constituted by equivalence instances ("'P' is true iff P") and nothing more. This handles cases that simple redundancy cannot, because it does not require the truth predicate to be eliminable in every context — only to be captured by the equivalence schema.

• Quine's disquotationalism holds that the truth predicate's function is to remove quotation marks. This emphasizes the logical role of truth in generalization and formal reasoning.

• Grover's prosententialism holds that "it is true" functions as a prosentence — a stand-in for a previously mentioned sentence, like a pronoun stands in for a name. This handles anaphoric uses of truth ("John said it would rain, and it is true") that simple redundancy cannot.

How the Theory Works

Simple Redundancy

In its simplest form, the redundancy theory says: "it is true that P" is always equivalent to "P." The truth predicate is redundant. Consider these pairs:

• "It is true that the Earth orbits the Sun" = "The Earth orbits the Sun"
• "It is true that 7 + 5 = 12" = "7 + 5 = 12"
• "It is true that justice is a virtue" = "Justice is a virtue"

In each case, the truth predicate adds nothing. The meaning is the same with or without it. If this is always the case, then truth is not a property — it is a redundant expression that can always be eliminated.

Handling Generalizations

The hard cases for the redundancy theory are generalizations — statements that quantify over many propositions without listing each one. "Everything the witness said is true" does not reduce to "everything the witness said" (which is incomplete). Ramsey's solution was to use quantification:

"For all p, if the witness said that p, then p."

This reformulation eliminates the truth predicate by using a variable ("p") that ranges over propositions. The truth of everything the witness said is captured not by attributing a property but by the logical structure of the quantification.

This solution works in principle but is awkward in practice. Natural language does not easily handle propositional quantification, and some philosophers have questioned whether the reformulation fully captures the original meaning. This challenge led to the development of more sophisticated deflationist accounts.

Performative Endorsement

Strawson's performative account handles a different set of cases. When someone says "that is true" in response to a claim, they are not restating the claim — they are endorsing it. The function of "true" here is pragmatic: it performs an act of agreement.

This account explains why "that is true" feels like a substantive contribution to the conversation even though it adds no new content. The contribution is not informational but interpersonal: it signals agreement, confirms reliability, or concedes a point. The truth predicate's function is social, not metaphysical.

Challenges to the Redundancy Theory

The Generalization Problem

The most significant challenge is handling generalizations. Ramsey's quantificational solution is technically elegant but practically awkward. Some philosophers argue that the reformulation does not fully capture the original meaning — "everything he said is true" seems to attribute a property (truth) to his statements, and replacing this with quantification may lose something.

Later deflationists (Horwich, Grover) developed accounts that handle generalizations more naturally, but the redundancy theory in its simplest form struggles with this challenge.

The Property Objection

Critics argue that truth does function as a property in some contexts. We say "truth is valuable," "truth is the aim of inquiry," "truth is correspondence to reality." These uses suggest that truth is something — a property, a value, an aim — that cannot be dismissed as redundant.

Deflationists respond that these uses are explicable without positing a substantive property. "Truth is valuable" means that true beliefs are valuable — and their value lies in what they let us do, not in a property called truth. "Truth is the aim of inquiry" means that inquiry aims at getting things right — at believing what is the case. These formulations capture the normative dimension of truth without treating it as a property.

The Paradox Problem

The liar paradox ("this sentence is false") creates difficulties for any theory of truth. If truth is redundant — if "it is true that P" just means "P" — then the paradox should be easily handled. But the liar sentence creates a problem: if it is true, then it is false; if it is false, then it is true. The redundancy theory, which treats truth as simple equivalence, does not have the resources to block the paradox.

Later deflationists have developed sophisticated logical tools (contextual theories, revision theories) to handle the paradoxes, but the simple redundancy theory does not address them.

Contemporary Relevance

The redundancy theory, though largely superseded by more sophisticated deflationist accounts, remains influential as the starting point of the deflationist tradition. Its core insight — that truth is thin, not thick — continues to shape contemporary philosophy of language and epistemology.

In philosophy of language. The redundancy theory initiated the deflationist program that dominates contemporary philosophy of truth. Most analytic philosophers today are deflationists of some stripe, and the redundancy theory is the ancestor of their views.

In epistemology. If truth is not a substantive property, then the classical definition of knowledge as justified true belief needs reinterpretation. The "true" condition may be thinner than it appears — a logical condition rather than a metaphysical one. This raises questions about what the other conditions (justification, belief) are conditions of.

In metaphysics. The redundancy theory is part of a broader philosophical tendency toward nominalism and minimalism — the rejection of positing entities or properties that are not needed for explanation. If truth does not require a property, perhaps other concepts (causation, necessity, meaning) do not either.

How to Apply This

1. Notice when "true" is redundant. In most ordinary uses, "it is true that P" is equivalent to "P." Pay attention to when the truth predicate adds nothing and when it seems to do work.

2. Distinguish content from endorsement. When someone says "that is true," they may be endorsing rather than describing. The performative function of truth is social, not informational.

3. Be cautious about metaphysical claims. If the redundancy theory is right, treating truth as a deep metaphysical property leads to confusion. Do not ask "what is the nature of truth?" but "how does the word 'true' function?"

4. Recognize the limits of simple redundancy. The redundancy theory in its simplest form cannot handle all uses of "true." Generalizations, indirect quotation, and paradoxical cases require more sophisticated tools.

5. Understand the deflationist program. The redundancy theory is the ancestor of contemporary deflationism. Understanding it is the first step to understanding the broader deflationist tradition that dominates contemporary philosophy of truth.

Sources

1. Stanford Encyclopedia of Philosophy, "The Deflationary Theory of Truth." Overview of deflationism and the redundancy theory's place within it.
2. Stanford Encyclopedia of Philosophy, "Truth." Context for the broader debate about theories of truth.
3. Stanford Encyclopedia of Philosophy, "Frank Ramsey." Context for Ramsey's original argument.
4. Stanford Encyclopedia of Philosophy, "P. F. Strawson." Context for the performative variant.

Related Topics

• What is deflationism about truth? — the broader family of views of which the redundancy theory is a member.
• Correspondence vs coherence — the inflationary alternatives.
• What is objectivity? — objectivity and truth are related but distinct.
• Truth vs fact — the distinction between truth and fact.