Peter Graham

This paper argues for the general proper functionalist view that epistemic warrant consists in the normal functioning of the belief-forming process when the process has forming true beliefs reliably as an etiological function. Such a process is reliable in normal conditions when functioning normally. This paper applies this view to so-called testimony-based beliefs. It argues that when a hearer forms a comprehension-based belief that P (a belief based on taking another to have asserted that P) through the exercise of a reliable competence to comprehend and filter assertive speech acts, then the hearer's belief is prima facie warranted. The paper discusses the psychology of comprehension, the function of assertion, and the evolution of filtering mechanisms, especially coherence checking.

Reductionism about testimony holds that testimonial warrant or entitlement is just a species of inductive warrant. Anti-Reductionism holds that it is different from inductive but analogous to perceptual or memorial warrant. Perception receives much of its positive epistemic status from being reliably truthconducive in normal conditions. One reason to reject the epistemic analogy is that testimony involves agency – it goes through the will of the speaker – but perception does not. A speaker might always choose to lie or otherwise deliberately mislead. It is argued that the force of this derives (in part) from Libertarianism about agency, and that Libertarianism, if it undermines the Anti-Reductionist explanation of why we are entitled to rely upon testimony, undermines the Reductionist explanation as..

Are we entitled or justified in taking the word of others at face value? An affirmative answer to this question is associated with the views of Thomas Reid. Recently, C. A. J. Coady has defended a Reidian view in his impressive and influential book. Testimony: A Philosophical Study. His central and most Oliginal argument for his positions involves reflection upon the practice of giving and accepting reports, of making assertions and relying on the word of others. His argument purports to show that testimony is, by its very nature, a “reliable form of evidence about the way the world is.” The argument moves from what we do to why we are justified in doing it. Although I am sympathetic with both the Reidian view and Coady’s attempt to connect why we rely on others with why we are entitled to rely on others, I find Coady’s argument ineffective