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Coherence Theory

Coherentism is belief in the coherence theory of justification - an epistemological theory opposing foundationalism and offering a solution to the regress argument. In this epistemological capacity, it is a theory about how belief can be justified. Coherentism also refers to the coherence theory of Truth.

__The regress argument__

The regress argument says 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:

* the series is infinitely long, with every statement justified by some other statement.
* the series forms a loop, so that each statement is ultimately involved in its own justification.
* 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. Similarly, empiricists take observations as providing the foundation for the series.

Foundationalism relies on the uneasy 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, that is, their theory of the world.

It is necessary for coherentism to explain in some detail what it means for a system to be coherent. At the least, coherence must include logical consistency. It also usually requires some degree of integration of the various components of the system. A system that contains more than one unrelated explanation of the same phenomenon is not as coherent as one that uses only one explanation, all other things being equal. Conversely, a theory that explains divergent phenomenon using unrelated explanations is not as coherent as one that uses only one explanation for those divergent phenomena. These requirements are variations on Occam's Razor. The same points can be made more formally using Bayesian statistics. Finally, the greater the number of phenomena explained by the system, the greater its coherence.

__Difficulties for coherentism__

The main criticism facing coherentism is probably simplest to state from the point of view of someone who holds to the correspondence theory of truth. It is that there is no obvious way in which a coherent system relates to anything that might exist outside of it. So, it may be possible to construct a coherent theory of the world, which does not correspond to what actually occurs in the world. In other words, it appears to be entirely possible to develop a system that is entirely coherent and yet entirely untrue.

It is surprisingly difficult to even state the problem from the point of view of a coherentist, because the phrase correspond to reality has a different meaning in a Coherentist system. For a Coherentist, reality is exactly the entire coherent system. It is simply not possible for a coherent theory not to correspond to reality, if reality is the very same thing as the entire coherent system.

Put another way, coherentists might reply to the critic that any substantial system that was not true would by definition contain some contradictions, and so be incoherent.

This should become clear by looking at the differences between a coherentist and correspondence account of a scientific advance. Newtonian mechanics was shown to be inconsistent with certain experiments, notably the Michelson-Morley experiment. The theory used by physicists was thereafter changed from Newtonian to relativistic mechanics.

One who held to a correspondence theory might say that there was an apparent lack of correspondence between the model (physics) and reality, and that the model was altered in order that it correspond to the observed facts.

A coherentist account might claim that before the Michelson-Morley experiment, Physics formed a coherent theory. But then the experiment was performed. These experimental results form a part of the account, yet the results were inconsistent with the expectations of the accepted theory. Thus the account was shown to be less coherent. This inconsistency was resolved by the development of Relativistic mechanics.

Any lack of correspondence of the theory with reality may eventually lead to a lack of coherence within the theory, and this leads to a modification of the theory to restore its coherence. There would be little or no practical difference between a Coherentist account and a Correspondence account of theory change.

It may remain logically possible for the entire system to be coherent, 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 arises 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.Zoom Huarache 2K4 Kobe