The concept of moral patienthood — who counts morally — is central to animal welfare philosophy and has evolved substantially over centuries.
The question of who counts morally — which beings are moral patients whose welfare matters — is foundational to animal welfare advocacy. The historical expansion of the moral circle from certain humans to all humans, and increasingly to non-human animals, follows from a consistent principle: subjective experience of suffering and wellbeing creates moral claims. The ongoing debates about invertebrate sentience, plant cognition, and AI welfare represent the active frontier of this expansion, with significant implications for how we organize animal welfare advocacy.