This article reconstructs the theoretical premises of Tom Regan’s animal ethics, the American philosopher recently disappeared who has given a fundamental contribu-tion to this area of practical ethics, by developing a theory of rights based on the extension to all subjects-of-a-life of Kantian notions such as inherent value and respect. Regan’s theory still remains the most rigorous foundation of an animal ethics alternative to the utilitarian approach of Peter Singer, but it is not without unresolved problems or not entirely satisfactory (...) solutions. To remedy some of them, in the final part the author tries to insert into the Reganian theoretical framework elements of gradualism. (shrink)