The recognition of animal sentience — the capacity to have subjective experiences — is the cornerstone of modern animal welfare thinking. Understanding where scientific and philosophical consensus stands helps advocates make their case.
The scientific case for widespread animal sentience is now robust and growing. The convergent evidence from neuroscience, behaviour, and evolution consistently supports the conclusion that suffering and positive experience are not uniquely human. The philosophical implications are profound: if sentience is widespread, the scale of morally relevant suffering caused by current human practices is enormous. The most important advocacy implication is that the burden of proof has shifted — we should assume sentience and require evidence to the contrary, rather than assuming its absence and requiring proof of its presence.