WHY BELIEVE WHAT PEOPLE SAY

The basic alternatives seem to be either a Humean reductionist view that any particular assertion needs backing with inductive evidence for its reliability before it can rationally be believed, or a Reidian criterial view that testimony is intrinsically, though defeasibly, credible, in the absence of evidence against its reliability. Some recent arguments from the constraints on interpreting any linguistic performances as assertions with propositional content have some force against the reductionist view. We thus have reason to accept the criterial view, at least as applied to eyewitness reports. But these considerations do not establish that any rational enquirer must have the concept of other minds or testimony. The logical possibility of the lone enquirer, who uses symbols and thereby expresses some knowledge of his world, remains open - but it is a question we have no need to pronounce upon. The practice of accepting observation-statements is in fact extended to chains of testimonies believed to start in perception or in some other kind of justification, but the arguments for doing this are not so clear.