Should animals have rights? Resolve the question by applying the principle of treating like cases alike. pick a right that humans have (eg to live uncaged). Ask: should humans have any justification for that right while denying it to animals (eg chickens, humans, elephants)? if there is no justification then animals should have that right. This rational avoids arbitrariness and lumping all species together. Ref: James Rachels, Do Animals Have a Right to Liberty?