Animals have no interests or rationality  Some philosophers argue that only beings that are able to make rational choices can have moral rights because the function of rights is to protect choice. Animals are not able to make rational choices because they can only follow instinct, they cannot follow logic.  Some philosophers believe that the function of rights is to protect interests. An argument from R.G. Frey argues that animals do not have interests because they do not have language. In order to desire something one must believe that one does not currently have that something and therefore believe that the statement ‘I have x’ is false. One cannot have such a belief unless one knows how language connects to the world. Animals can’t talk so they certainly are unable to know what it is that the sentence ‘I have x’ means in the real world. Therefore animals cannot have desires. Without desires animals cannot have interests. If the function of rights is to protect interests then animal rights serve no purpose. [1]  [1] Frey, R,G. "Rights, Interests, Desires and Beliefs." Ethics for Everyday. (Benatar, D Ed.) McGraw Hill: New York. 2002