Killing an animal in violation of anti-cruelty statutes is universally punished less severely than murdering a human being. Is this practice morally justifiable? I believe it is. In order to understand why, we must transcend the “sentience argument”. Both animal welfare and animal rights advocates believe that the rights/interests of animals stem from the fact that they’re sentient beings. Animals should be protected from torture, for example, because they can feel pain. Given that causing pain is the paradigmatic instance of wrongful conduct, society should criminalize unjustifiably inflicting pain on animals.
The sentience argument cannot explain why killing a human being is prima facie more wrongful than killing a nonhuman animal. Since both human and nonhuman animals have the capacity to feel pain, it would seem that harming them is equally wrongful. What, then, accounts for the generalized intuition that murder is worse than wrongfully killing an animal? In my opinion, what typically entitles humans to more protection than nonhuman animals is that they possess morally relevant traits that animals lack – a capacity for self-consciousness and an acute awareness of the future.
These traits matter because beings that are self-aware and have a sense of the future are more prone to suffering than creatures lacking these features. Self-conscious beings, for example, fear death not only because of the possible pain that the process of dying might cause, but also because of the suffering that having advanced knowledge of one’s demise might cause (think of the suffering of a prisoner in death row who agonizes when he contemplates his future death). Furthermore, since self-conscious beings that are aware of the passage of time make plans for the future, killing them entails not only terminating their existence, but also taking from them the possibility to fulfill their plans and aspirations. Killing beings lacking these characteristics does not harm them in the same way. Given that they have no awareness of the future, they are not conscious of the significance of their death. Since they lack the ability to plan for tomorrow, they have no sense of the meaning of death or of what they lose by not waking up the next morning.
I acknowledge that some animal law advocates may object to my proposal because it might be interpreted to afford rights depending on the degree of similarity that exists between nonhuman creatures and human beings. In spite of this possible criticism, the view I propose here should not be rejected as speciesist because the distinctions drawn here are not grounded on the basis of the being belonging to a particular species, even if it is claimed that some species deserve more protection than others. Ultimately, the amount of legal protection is dependent on the being’s capacity for self-consciousness and awareness of the future, not its belonging to a particular species. The fact that human beings typically share those traits is beside the point, for what really matters is the traits, not the species.