Knowing at Second Hand

Participants on both sides of the contemporary debate between reductionism and anti‐reductionism about testimony commonly describe testimonial knowledge as knowledge acquired at second hand. I argue that fully appreciating the distinctive sense in which testimonial knowledge is secondhand supports anti‐reductionism over reductionism but also that it supports a particular kind of anti‐reductionism very different from that typically offered in the literature. Testimonial knowledge is secondhand in the demanding sense of being justified by the authority of a speaker where this requires that epistemic responsibility for meeting challenges to the audience's testimonial knowledge is shared between speaker and audience. The epistemic credentials of testimonial knowledge are in this sense importantly interpersonal.