Religion has never befriended the cause of humaneness. Its monstrous doctrine of eternal punishment and the torture of the damned underlies much of the barbarity with which man has treated man; and the deep division imagined by the Church between the human being, with his immortal soul, and the soulless "beasts", has been responsible for an incalculable sum of cruelty. - Henry Salt
Salt's essential philosophy is summed up in his book, Creed Of Kinship; here he explains how he "thoroughly disagreed with the present established religions," but had a firm religious belief of his own which he called a Creed Of Kinship.
Founded on rationalism and underpinned by unselfish deeds, it simply demanded a recognition of the biological and evolutionary affinity between man and man and human and sub-human.
Salt was prepared to "hold a truce between those who sought similar reforms but from a different religious foundation, but ultimately he felt his Creed would "outlive and outlast all the complicated doctrines theology has thrown up."