Abstract: This paper aims to assess R. G. Frey’s analysis of Leonard Nelson’s argument (that links interests to rights). Frey argues that claims that animals have rights or interests have not been established. Frey’s contentions that animals have not been shown to have rights nor interests will be discussed in turn, but the main focus will be on Frey’s claim that animals have not been shown to have interests. One way Frey analyses this latter claim is by considering H. J. McCloskey’s denial of the claim and Tom Regan’s criticism of this denial. While Frey’s position on animal interests does not depend on McCloskey’s views, he believes that a consideration of McCloskey’s views will reveal that Nelson’s argument (linking interests to rights) has not been established as sound. My discussion (of Frey’s scrutiny of Nelson’s argument) will centre on the dialogue between Regan and Frey in respect of McCloskey’s argument. I will endeavor to update the dialogue by providing a re-interpretation of ‘rights’ in Nelson’s argument.