The bioethical literature demonstrates both substantive contest over the moral status of entities such as human embryos, and approaches that aim to find morally sound prescriptions in light of fundamental disagreement and uncertainty about identification of their moral status. Amongst such latter approaches, we find Shaun Pattinson's moral precautionary thesis, for which he provides a renewed defence in his recent book Law at the Frontiers of Biomedicine. Pattinson's overarching moral theory centres on the rights of moral agents. In relation to (...) the question of that theory's application, the moral precautionary thesis addresses how, and with what degree of certainty, one moral agent may identify or recognise another. Pattinson roots his precautionary thesis in the problem of other minds. In this article, I argue that that is a mistaken starting point when held against the consequent epistemic claims that Pattinson makes. Furthermore, in examining Pattinson's reasoning, including against earlier objections that have been levelled, I argue that he generates additional problems for accepting the cogency of his thesis. (shrink)