The coherence theory of truth states that the truth of any proposition consists in its coherence with some specified set of propositions. According to this theory, a proposition is true if it coheres or fits in with a broader system of propositions and false if it contradicts or conflicts with that system.
The coherence theory differs from the correspondence theory of truth, which holds that true propositions correspond to facts about the world. While the correspondence theory focuses on the relationship between propositions and objective reality, the coherence theory emphasizes the relations between propositions. A coherentist holds that propositions are true insofar as they hang together in a coherent web of beliefs. What makes the web coherent is the logical and semantic relations that obtain between its components. Logical relations include entailment, compatibility, and consistency. Semantic relations include meaning, implication, and presupposition.
The coherence theory has been motivated by idealism, pragmatism, and various anti-realist doctrines in philosophy. Idealists hold that reality is mental or spiritual in nature, not physical. So truth cannot be defined as correspondence with a mind-independent world. Pragmatists reject the notion of objectively pre-existing facts and instead define truth in terms of usefulness and success. Anti-realists deny that truth must answer to objective reality at all. Coherentism coheres with these views by defining truth intensionally in terms of relations between propositions rather than extensionally in terms of propositions’ links to the world.
The coherence theory also gels with holism in epistemology. According to holism, beliefs are justified insofar as they fit together in a coherent system. Coherentism transfers this holistic concept of justification to the theory of truth. Just as a belief is justified by virtue of belonging to a coherent set of beliefs, so a proposition is deemed true by virtue of belonging to a coherent set of propositions. Coherence functions as both the mark of truth and the criterion of justification.
Various coherence theories have been proposed that differ according to how they specify which propositions must cohere with which others. Harold Henry Joachim argued that true propositions form a comprehensive, maximal system of propositions. Less inclusive sets of propositions within this system can be evaluated for coherence and truth based on their connections to the maximal set. Brand Blanshard specified that any set of propositions counts as coherent so long as its members “imply or explain or render probable each other.” Laurence BonJour defined coherence in terms of how well a set of propositions “hangs together” logically while also meshing with background knowledge.
Coherentists face several challenges. One issue is specifying what exactly coherence amounts to. How logically tightly knit must a set of propositions be in order to qualify as coherent? When does coherence max out? Another problem is explaining what makes coherence truth-conducive. Why should greater coherence between propositions entail greater likelihood of their truth? Also, positing coherence as the mark of truth seems to make truth hostage to our own limited perspectives. Our assessment of whether some proposition coheres with our other beliefs could be mistaken given our incomplete knowledge. This raises the threat of epistemic relativism. Coherentism must explain what safeguards against relativism.
Overall, the coherence theory rejects a realist, correspondence-based notion of truth in favor of an anti-realist, holistic approach focused entirely on internal semantic/logical relations between propositions. The theory continues to spark debate among philosophers as they grapple with its implications for realism, objectivity, relativism, holism, and the very nature of truth itself.
Key Proponents of the Coherence Theory
Some important philosophers and thinkers who have advocated or developed versions of the coherence theory of truth include:
– Harold Henry Joachim – British idealist philosopher who viewed truth as systematic coherence. He proposed that propositions are true if they belong to the most comprehensive coherent system.
– Brand Blanshard – American philosopher who defined a coherent set simply as one whose members “imply or explain or render probable each other.”
– Laurence BonJour – Contemporary American epistemologist who argues that the coherence of a system of beliefs is Truth-conducive because coherence entails probabilistic consistency.
– Immanuel Kant – Argued that empirical judgments must cohere with each other according to a priori categories of the understanding. This cohesion makes empirical knowledge objective.
– G.W.F. Hegel – Held that dialectical development of thought leads to an Absolute system in which contradictions are resolved through systemic coherence.
– F.H. Bradley – British idealist who believed that partial truths gain truth by finding their place in an Absolute coherent whole.
– William James – American pragmatist who argued that truth is verified through experience and must cohere with other verified beliefs.
– Otto Neurath – Logical positivist who promoted coherentism by likening knowledge to a boat whose parts must be repaired piecemeal while staying afloat.
– Donald Davidson – Developed a coherence theory of knowledge whereby beliefs are justified by virtue of fitting into a coherent logical structure.
While differing in their metaphysical assumptions, these thinkers all converged on coherence as the key criterion or nature of truth and knowledge. Their views laid the foundation for contemporary coherentist theories.
Objections to the Coherence Theory
Some of the main objections that have been raised against the coherence theory of truth include:
– It fails to establish correspondence with objective facts – Critics argue that coherence alone cannot guarantee that a set of beliefs accurately represents reality. False propositions can cohere.
– Truth is hostage to what we can conceptualize – Our limited minds may fail to conceive of the correct system; truth should not be dependent on what we can conceive.
– Incoherent truth – There seem to be true propositions that contradict each other, so coherence cannot be a necessary condition for truth.
– No criterion for what counts as coherence – Different philosophers define coherence differently. There is no agreed upon standard for what makes a system coherent.
– Unable to explain truth-value shifts – A proposition can move from being true to false (or vice versa) while retaining coherence in a system of beliefs. But truth is absolute.
– Leads to epistemic relativism – Coherence may only be coherence relative to a given conceptual scheme. This threatens objectivity.
– The externalist critique – External factors, like causal links between beliefs and the world, should matter for truth, not just internal coherence.
– No explanation for truth-conduciveness – It is not clear why coherence should track truth. What rules out systems of false but coherent beliefs?
These objections attempt to show that the coherence theory either fails to properly define truth, succumbs to subjectivism and relativism, or provides an inadequate guide to objective truth about the world. Defenders of coherentism have responses to these objections, but many see them as posing serious challenges.
Responses to Objections
Here are some ways proponents of the coherence theory of truth have responded to the main objections raised against their view:
1. Correspondence objection – Coherentists argue that coherence and correspondence may be mutually reinforcing criteria, with coherence ensuring that beliefs accurately depict relations between objects in the world.
2. Truth conditional on our own minds – Some coherentists hold that the Absolute (for idealists) or empirical coherence over time (for pragmatists) can take our limited perspectives into account. Coherence need not be confined to what we currently conceive.
3. Incoherent truths – Apparent counterexamples may be resolved by enlarging the system of propositions or recognizing distinctions between levels of coherence. Local coherence may yield to wider coherence.
4. No criterion for coherence – While there is no agreed upon criterion, coherentists argue that coherence admits of degrees, is an internally coherent concept itself, and is recognizable even if hard to define.
5. Truth value shifts – Coherentists can argue that changed truth conditions prompt a revision of other beliefs to restore coherence. The system evolves while coherence is maintained.
6. Relativism – Conceptual schemes that produce empirical coherence over time converge toward objective truth. Alternative conceptual schemes are tested against experience.
7. Externalist critique – Coherentists can argue that coherence requires fitting beliefs to experience, not just internal logical relations. Or, internal relations track external ones.
8. Truth-conduciveness – A coherent system is like a web that strengthens with each thread. Coherence integrates evidence, increasing probability of truth.
While objections pose difficult challenges, coherentism has resources to maintain itself as a viable, anti-realist alternative to correspondence theories of truth. Coherentists and critics continue an extensive debate over the merits of this perspective.
The Coherence Theory in Contemporary Philosophy
While the heyday of classical coherentism was in the late 19th and early 20th centuries, contemporary philosophers continue to defend, criticize and revise coherence theories of truth and knowledge. Some current developments include:
– New coherentist epistemologies, like Laurence BonJour’s systematic coherence theory, which adds an empiricist component to traditional coherentism.
– Coherentist theories of justification, which argue that coherence is the prime source of epistemic justification for beliefs.
– Coherentist approaches in quantum logic, which propose that the paradoxical nature of quantum phenomena reveals failures of classical realist truth conditions.
– Deflationary approaches that deny truth has a substantive property that can be defined, coherentist or otherwise. Coherence then becomes primarily an epistemic principle.
– Critiques of coherentism based on developments in externalist epistemology, which emphasize causal links between mind and world.
– Influential coherentist holdouts like Richard Rorty, who denied truth has an essence beyond social justification.
– Reconciliatory theories combining coherence with correspondence, like Rescher’s “coherence theory of truth.”
– Feminist and postmodern critiques of coherence theories for overly conservative assumptions about rational unity and communal consensus.
– Debates over whether coherentism or correspondence better fits with naturalism and scientific realism in analytic philosophy.
While no longer a dominant position, coherentist themes still shape many debates in epistemology and serve as a critical counterpoint to mainstream correspondence theories. Coherentism retains significant support as an anti-realist approach to the theory of truth.
Coherence Theory in Analytic Philosophy
The rise of analytic philosophy in the 20th century was marked by skepticism towards coherence theories of truth and a revival of correspondence theories. Key reasons include:
– Analytic philosophy embraced logical atomism and a foundationalist epistemology viewing knowledge as grounded in self-evident truths, challenging coherence theories.
– Logical positivists like Moritz Schlick endorsed a correspondence theory verified by empirical science and logic, rejecting metaphysics.
– Analytic philosophy has tended to embrace scientific realism and naturalism, which cohere better with correspondence truth.
– The “linguistic turn” focused philosophical attention on referential theories of meaning assumed torequire correspondence truth.
– Externalist theories of justification emphasizing causal links between mind and world challenged the coherence theory.
– Willard Van Orman Quine criticized the dogmas of empiricism and the analytic-synthetic distinction, undermining logical positivism but not coherentism itself.
– Bertrand Russell and later analytic philosophers like J.L. Austin and John Searle developed correspondence theories of truth and reference.
– Saul Kripke’s causal theory of reference assumes names refer to objects in the world, not a coherent system of meanings.
However, some analytic thinkers like Otto Neurath, Donald Davidson, Hilary Putnam, and Nicholas Rescher have developed coherence theories compatible with core analytic assumptions. And deflationary, minimalist, and pragmatist theories of truth in analytic philosophy cohere well with anti-realist aspects of coherentism. So while correspondence theories dominate, coherentism remains an analytic option.
Comparison to Correspondence Theory
The coherence and correspondence theories offer opposing views about the nature of truth:
– Correspondence says true beliefs match objective reality while coherence says truths cohere with other beliefs.
– Correspondence is metaphysical and ontological while coherence is semantic and holistic.
– Correspondence is realist and foundationalist while coherence is anti-realist and relies on mutual support between beliefs.
– For correspondence, beliefs make truth claims about the world. For coherence, the world is secondary to the belief system.
– Correspondence says beliefs are true by virtue of relations between themselves and the world. Coherence says relations among beliefs make them true.
– Correspondence Truth relates to empirical verification and foundationalism. Coherence truth relates to conservatism and idealism.
– Correspondence aims for certainty and objectivity. Coherence accepts fallibilism and relativism.
– Correspondence cares about reference and meaning. Coherence cares about logical interconnections between propositions.
While opposites in many regards, some thinkers argue correspondence and coherence each capture important intuitions about truth. Truth may require both coherent mental systems and empirical correspondence with observable facts. Integrating the two remains an ongoing project for many contemporary theories of truth.