John W. Bender

Coherence, Justification, and Knowledge: The Current Debate

Despite Emerson’s maxim associating consistency with little minds, no philosopher champions incoherence, and this is how it should be. Since the most basic virtue of a belief is that it be knowledge, and since no belief stands alone, but is held in the context of other things believed, sound relations among beliefs are bound to be epistemically important.

Fundamental Troubles with the Coherence Theory

In evaluating any coherence theory, we must answer two classic questions: (A) What is coherence ? and (B) Can there be several internally coherent but mutually incompatible systems of belief? Given a plausible answer to (A), the answer to (B) must be “Yes.” This dooms any coherence theory of truth. For trivially, there cannot be two incompatible systems of true beliefs. But a “Yes” answer to (B) is a point in favor of coherence theories of justification. For a justified belief need not be true, and it is quite possible for two individuals with incompatible beliefs to both be fully justified in their beliefs. Note that a coherence theory of justification would not entail that there may be incompatible systems of knowledge. For knowledge requires true as well as justified belief. Given two individuals with incompatible but fully justified beliefs, at most one can have knowledge.

Technical flaws in the coherence theory

ConclusionWe have argued that Lehrers definitions of coherence and justification have serious technical defects. As a result, the definition of justification is both too weak and too strong. We have suggested solutions for some of the problems, but others seem irremediable. We would also argue more generally that if coherence is anything like what Lehrers theory says it is, then coherence is neither necessary nor sufficient for justification. While our current objections are directed at the ‘letter’ of Lehrers theory, other criticisms can be aimed at its very ‘spirit’. We would argue that coherence is unnecessary for justification because of the existence of ‘basic beliefs’, those about self-presenting states (‘I have a tingling sensation in my leg’) or self-evident truths (‘All men are men’). Such beliefs may be justified even though there are no other propositions in the subjects acceptance system that makes them more probable than competitors. Coherence is, moreover, insufficient for justification, because it ignores the inferential structure of the subjects acceptance system, and requires no justification of any kind for the subjects acceptance system itself. But we must develop these more fundamental objections on another occasion.

Skepticism, Justification and the Trustworthiness Argument

We must, therefore, in every reasoning form a new judgement, as a check or controul on our first judgement or belief; and must enlarge our view to comprehend a kind of history of all the instances, wherein our understanding has deceived us, compar’d with those, wherein its testimony was just and true.