Gabriel Malagutti
University of Lisbon
Non-reductionism in the epistemology of testimony, is the view that all one needs in order to justify testimonial acceptance, is the lack of negative reasons – defeaters. Lackey (2008) has introduced the biggest challenge to non-reductionist accounts of testimony: The Alien Case. Perrine (2014) published a reply to Lackey, arguing that the conjunction of background information we acquire regarding testimony, plus the knowledge that the alien is a radical new source of knowledge, enables the hearer with a normative defeater concerning the reliability of the alien’s testimony. Against Perrine, I argue that his appeal to background information is asymmetric. The asymmetry comes about by splitting background information in a positive and negative aspect. The negative half, concerning the information of how testimony goes awry, is applied to testimony simpliciter. The positive part is restricted to human-type testimony, for we know how human testimony is reliable and know that Lackey-type sceptical concerns are misplaced regarding human testimony. This positive aspect, that is not present in non-human testimony, allows one to defeat the negative evidence in the former half of the background information. Given the asymmetry, it allows Perrine to endorse a sceptical attitude concerning alien testimony, for there is a defeater in the negative part of background information, that, unlike human-type testimony, by absence of the positive part, remains undefeated. This asymmetry, I argue, is unwarranted: either the positive and negative aspect of the background information applies to testimony simpliciter, or both aspects apply exclusively to human-type testimony. Attempting to correct the asymmetry whilst preserving the normative defeater, no matter the route one takes, I argue, is impossible. Attempts to do so will inevitably lead to the wrong assessment of the case (losing the normative defeater, endorsing unjustified acceptance) or reductionism. Given the ad hoc asymmetry, Perrine’s solution must be rejected, attempts to justify the asymmetry are equally flawed. As such, Perrine is unable to defend non-reductionism against the Alien Case; a new tactic must be employed.
Chair: Sonja Riegler
Time: September 7th, 10:40-11:10
Location: SR 1.004
SOPhiA 2026 