Frances Power Cobbe led the Victorian movement against vivisection. Cobbe is often remembered for her animal welfare campaigning, but it is rarely recognized that she approached animal welfare as a moral philosopher. In this article I examine the philosophical basis of Cobbe’s anti-vivisectionism. I concentrate on her 1875 article ‘The Moral Aspects of Vivisection’, in which Cobbe first locates vivisection within the historical movement of Western civilization and the tendency for science to supersede religion, and then endeavors to refute the defenses of vivisection one-by-one. I emphasize these philosophical considerations that led Cobbe to oppose animal experimentation on a reasoned basis.