 Deontological ethical theories, in contrast, maintain that whether an action is right or wrong is for the most part independent of whether its consequences are good or bad (see the entry on  deontological ethics).  From the deontologist perspective, there are several distinct moral rules or duties (e.g., “not to kill or otherwise harm the innocent”, “not to lie”, “to respect the rights of others”, “to keep promises”), the observance/violation of which is intrinsically right/wrong; i.e., right/wrong in itself regardless of consequences. When asked to justify an alleged moral rule, duty or its corresponding right, deontologists may appeal to the intrinsic value of those beings to whom it applies. For instance, “animal rights” advocate Tom Regan (1983) argues that those animals with intrinsic value (or what he calls “inherent value”) have the moral right to respectful treatment, which then generates a general moral duty on our part not to treat them as mere means to other ends. We have, in particular, a prima facie moral duty not to harm them. Regan maintains that certain practices (such as sport or commercial hunting, and experimentation on animals) violate the moral right of intrinsically valuable animals to respectful treatment. Such practices, he argues, are intrinsically wrong regardless of whether or not some better consequences ever flow from them. Exactly which animals have intrinsic value and therefore the moral right to respectful treatment? Regan’s answer is: those that meet the criterion of being the “subject-of-a-life”. To be such a subject is a sufficient (though not necessary) condition for having intrinsic value, and to be a subject-of-a-life involves, among other things, having sense-perceptions, beliefs, desires, motives, memory, a sense of the future, and a psychological identity over time.