Contractarian ethics grounds morality in agreements among rational agents, which traditionally excluded animals — but philosophers have developed extensions that bring animals within moral consideration.
Contractarian ethics poses a genuine challenge for animal advocates because its standard formulations ground moral status in rational agency. However, the extensions developed by philosophers such as Rowlands and Nussbaum show that the core intuition behind contractarianism — that moral status derives from the capacity for a life with its own value — can be applied to animals without distorting the framework. The capabilities approach in particular provides a practically useful tool for identifying what welfare conditions each species requires to flourish.