Over its publication history, nine volumes were issued.[2] These included the unpublished works of Peter Singer, Tom Regan, Edward Johnson, James Rachels, among others.[3] The journal has been described as having been instrumental in introducing analytic philosophy to an Italian audience,[1] as well as information about the animal liberation movement.[4] It is also credited as internationally popularising the term "rights-holders" to describe animals.[1] A special issue dedicated to the Great Ape Project, was published in 1996;[5] Peter Singer served as special co-editor.[6]