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Coherentism is an epistemological position opposing foundationalism, and is one solution to the regress argument or the problem of the criterion. It is a theory about how truth and belief can be justified. It is related to, but is more widely applicability than, the coherence theory of truth.

Table of contents
1 The regress argument
2 Foundationalism
3 Coherence
4 Difficulties for Coherentism

The regress argument

The regression argument has it that, given some statement P, it appears reasonable to ask for a justification for P. If that justification takes the form of another statement, P', one can again reasonably ask for a justification for P', and so forth. There are three possible outcomes to this questioning process:

  1. the series is infinitely long, with every statement justified by some other statement.
  2. the series forms a loop, so that each statement is ultimately involved in its own justification.
  3. the series terminates with some statements that are not justified.

An infinite series appears to offer little help, since it is basically impossible to check that each justification is satisfactory. Relying on such a series quickly leads to scepticism. A loop begs the question. Coherentism is sometimes characterised as accepting that the series forms a loop, but although this would produce a form of Coherentism, this is not what is generally meant by the term.


One might conclude that there must be some statements that, for some reason, do not need justification. This view is called Foundationalism. For instance, Rationalists such as Descartes and Spinoza developed axiomatic systems that relied on statements that were taken to be self-evident: 'I think therefore I am' is the most famous example. Alternately, empiricists take observations as providing the foundation for the series.

Foundationalism sits uneasily on the claim that it is not reasonable to ask for justification of certain propositions. If someone makes an observational statement, such as 'it is raining', it does seem reasonable to ask how they know. Coherentism does not make this claim, insisting that it is always reasonable to ask for a justification for any statement.


Coherentism denies the validity of the regression argument. The regression argument makes the assumption that the justification for a proposition takes the form of another proposition: P" justifies P', which in turn justifies P. For Coherentism, justification is a holistic process. P is not justified as a part of some inferential chain of reasoning, but because it coheres with some system of which it forms a part. Usually the system is taken to be the complete set of beliefs of the individual or group.

It is incumbent on Coherentism to explain in some detail what it is for a proposal to be coherent. At the least, coherence must include logical consistency. It usually includes also some allowance for the degree of integration of the various components of the system. A system that contains more than one divergent, unrelated set of explanations is not as coherent as one that uses fewer explanations, all other things being equal. This is a variation on Occam’s razor. The same point can be made more formally by reference to Bayesian statistics. Finally, a system that is able to explain a wider range of phenomena will generally be considered t be more coherent than one which is unable to explain the same phenomena.

Difficulties for Coherentism

Foremost amongst the problems facing Coherentism is that there is no obvious way in which a Coherent theory relates to anything external to it. It may be entirely possible to construct a consistent system of the world, for instance, which does not correspond to what actually occurs in the world. In other words, consistency does not equal correspondence.

Whilst strictly true, this criticism might have little practical effect on a reasonably refined system, since a lack of correspondence should result in a lack of consistency within the system itself. This might best be explained by an example. Newtonian mechanics was shown to be inconsistent with certain experiments, notable the Michelson-Morley experiment. There is, then, an apparent lack of correspondence between the system and reality. This lack of correspondence led to the development of Relativistic mechanics. A Coherentist account might have it that, since the Michelson-Morley experiment itself forms a part of the system, the lack of correspondence would manifest itself in a lack of consistency in the system – the experiment was inconsistent with Newtonian mechanics. This inconsistency was resolved by replacing Newtonian with Relativistic mechanics. A lack of correspondence in a part of the system leads directly to a lack of consistency, and this leads to a modification of the system to remove the inconsistency.

It may remain logically possible for the entire system to be consistent, yet not correspond to reality. Coherentists would argue that this eventuality is extremely unlikely, given the huge range and variety of beliefs that go into the whole system. The question also arrises as to how we could ever know that there was such a large scale lack of correspondence – how, for example, could we ever know that we were being deceived by Descartes’ demon? At this level, the problem becomes one for the whole of epistemology, not just for Coherentism.