This paper readdresses important epistemological issues raised by Barry Hallen and J. Olubi Solidipo’s pioneering philosophical fieldwork among Yoruba herbalists or masters of medicine (onisegun). More precisely, I shall primarily investigate, as well as object to, the unduly restrictive view they take on testimony in Yoruba epistemic practice. With this criticism as the starting point, I explore different ways in which an “oral culture” like the Yoruba can rely on testimony as a source of justification without succumbing to the gullible and uncritical attitude towards tradition such societies have been charged with. To this purpose I put to use relevant developments within analytic epistemology taking place after Hallen and Sodipo published their work.