Science and the Denial of Animal Consciousness
For the main currents of philosophy — and for common morality — sentience is a necessary condition for a being to be a moral patient (for utilitarianism it is also a sufficient condition). The vividness with which we are conscious of a being's emotions determines the amount of attention we will give her. A decisive factor for bringing humans to treat other animals ethically is thus the unrestricted recognition of their possession of a mental life, of the fact that they think, desire, feel and so on.