I ' m glad Yourofksy ' s getting the message out he ' s right . But philosophically speaking , I think there ' s a more rigorous case for veganism . So , for example , here ' s an argument which I ' ve never heard logically refuted The dominant view is that human interests always trump nonhuman ones , because our cognitive abilities are superior in certain areas , from general intelligence to a capacity for abstract reasoning . But there are a few problems with that whole view . For starters , where does that leave people with severe mental disabilities , who fall below that threshold ? Many nonhuman animals are clearly much more selfaware and intelligent , and yet , as Singer has pointed out , they ' re given a lot less moral consideration . So the question comes down to Why is this the case ? Most people would respond because they aren ' t human . That just begs the question , though Why is being human a relevant criterion , when the members of the other are more aware , more sensate than certain humans ? To say that being human automatically gives all humans greater moral status isn ' t any different from racism and sexism it ' s an arbitrary appeal to group membership . If you want to elevate every human above every nonhuman , visavis moral status , you have to provide a morally relevant criterion shared by all humans which no other animal has . Where does that leave us ? Well , if we want the sphere of ethical consideration to encompass all humans , it ' s the capacity to suffer which is the baseline but by necessity that includes most nonhumans too . In fact , drawing on evolutionary biology , we know the ability to suffer is similar if not identical between species , including humans and others . Once we relinquish our speciesism , then , the moral calculation comes down to weighing the similar interests of individuals equally , without concern for species . That would require a radical break from people ' s lifestyles . So , to sum up , speciesism is a prejudice which arbitrarily uses species membership to assign different moral weight to the interests of individuals , even when their interests in avoiding suffering are similar . An example of speciesism is someone valuing their trivial interest in eating animals over the fundamental interest of animals in not suffering and dying . When someone has choices available , that ' s ethically indefensible . People appeal to nature to try to justify this , but that falls into the naturalistic fallacy it tries to derive values ought from facts nature , an is .