Peer Disagreement, Testimony, and Personal Justification

In this paper, I consider the problem of peer disagreement: What should one do in a case in which one who is an epistemic peer disagrees with one? One of the flaws with what has come to be known as the “equal weight view” is that it misconceives the asymmetry between the peer’s opinion and one’s own: the peer’s opinion just by itself carries evidential value, whereas one’s own just by itself carries none. This shows, I claim, that the evidential weight relevant to a peer’s disagreement is that conveyed ordinarily by testimony. I argue against the so-called “total evidence view” that the strategy it mandates cannot be put into practice, because of the objective way in which it conceives of evidence. I conclude by providing my own view, which treats the testimony of peers as testimonial evidence, to be weighed in accordance with one’s personal justification system