Knowledge, Scepticism and Coherence

Abstract

I defend a coherence theory of knowledge.2 It is a reply to the sceptic and at the same time an admission that we cannot prove the claims of the sceptic to be in error. We have much to learn from the sceptic, including what knowledge is. I shall articulate, however briefly, a coherence theory of knowledge. I shall then explain what sort of concession to the sceptic it permits. The theory is based on the assumption that we are fallible, that is, that we can err, no matter how well justified we might be in what we accept. Coherence yields a theory of justification, not of truth, but an adequate match between coherence and truth is all that is required to yield knowledge. Let us see how. Knowledge is based on what we accept as true and on the truth of what we accept. But the acceptance of something true does not suffice for knowledge, for we may be unjustified in what we accept and yet accept something true. We may, in fact, proceed by the most irrational methods and fallacious reasoning and still be lucky enough to accept something true. My own view of acceptance is that it differs from belief in constituting a positive evaluation of belief at a metamental level of evaluation. Thus, acceptance, unlike mere belief, constitutes the best efforts of a person to obtain truth and avoid error. But our best efforts can go awry. What, then, must we add to convert our acceptance of something true to knowledge of it? The answer is justification, but justification is the place where the sceptic dwells. We must enter, nonetheless. The sceptic raises objections to what we accept, whether it concerns tables, persons, galaxies or neutrinos. And the sceptic can be expected to raise doubts, hyperbolic doubts from Descartes or more mundane doubts from everyday life. The sceptic might appeal to a powerful demon, if demonology attracts her, or a malicious scientist manipulating our brain in a vat, if science fiction attracts her. Or she might appeal to our dreams, the illusions of sense, or even our familiar lapses of memory. How should I reply? What can I appeal to in order to argue that I know the sceptic is wrong in her hyperbolic and mundane doubts?