In the third volume of Masks of God – Campbell’s main work on comparative mythology – this distinguished mythologist examines the pagan beliefs of the Greeks, Romans and Celts along with the Abrahamic religions: Zoroastrianism, Judaism, Christianity and Islam. Campbell examines the characteristics and common roots of these mythological systems, while demonstrating the process that involved the transition in the West from mythologies that focused on the feminine to those that focused on the masculine. Campbell’s four-volume study of the religions and mythological systems of the world, Masks of God, is undoubtedly a masterpiece. Concluding it, he wrote the following:

I find that the main achievement for me was the confirmation of a thought that I had long and truly cherished: about the unity of the human race, and not only in the biological plane, but also in its spiritual history , which everywhere revealed itself in the form of a single symphony, the themes of which were proclaimed, developed, carried to the limit, and then turned over, distorted and reaffirmed and which today, in the great fortissimo of all these movements, fused together, irresistibly strives forward towards some majestic culmination, from which her next impulse will have to be born.