Abstract

Is there anything you know entirely off your own bat? Your knowledge depends pervasively on the word of others. Knowledge of events before you were born or outside your immediate neighborhood are the obvious cases, but your epistemic dependence on testimony goes far deeper that this. Mundane beliefs — such as that the earth is round or that you think with your brain — almost invariably depend on testimony, and even quite personal facts — such as your birthday or the identity of your biological parents — can only be known with the help of others. Science is no refuge from the ubiquity of testimony. At least most of the theories that a scientist accepts, she accepts because of what others say. The same goes for almost all the data, since she didn't perform those experiments herself. Even in those experiments she did perform, she relied on testimony hand over fist: just think of all those labels on the chemicals. Even her personal observations may have depended on testimony, if observation is theory- laden, since those theories with which it is laden.