Knowledge From Others
Our reliance upon testimony is too important and too fundamental.
From Testimony: A Philosophical Study, where we start to see how the study of knowledge derived from others, or testimony, has been dismissed and ignored going all the way back to Plato:
Socrates uses the example of proceedings in a law case and points out that a jury may be convinced of certain facts about a robbery merely by the persuasive and rhetorical skills of a lawyer and yet they can hardly be said to know these facts even though their beliefs are true. Plato could perhaps have rested his case on the distinction between beliefs produced by rhetorical trickery or non-rational persuasion on the one hand and beliefs supported by relevant evidence on the other, but he seems to want to go further and insist that beliefs about the robbery could never amount to knowledge for the jury since these are facts 'which can be known only by an eye-witness'. If we are to take seriously what Plato says here then he must be seen as placing a strong restriction upon what sorts of account or reason (r) can be used to fill in clause (3) of the knowledge definition [A has legitimate reason r for believing p], a restriction which would relegate to the realm of mere true opinion all beliefs based upon report, even the report of eyewitnesses who may themselves know what is the case . . .
Indeed the passage we have been discussing is noteworthy amongst Plato scholars not for its dismissal of testimony as a source of knowledge but for its granting of that status to ordinary perception, an accolade which elsewhere Plato denies it . . . This line of defence is interesting, from the point of view of our present inquiry, precisely because it has Plato relying upon some sort of 'obviousness' about testimony's not being a source of knowledge and about its inferiority, in this respect, to perception. Subsequent thinking about knowledge, at both the casual and the philosophical level, has been for the most part remarkably consistent with this intuition; either it has ignored testimony altogether or it has been cursory and dismissive. . . .
I shall argue that this tradition of neglect is a bad one and that our reliance upon testimony is too important and too fundamental to merit such casual treatment.
