William James and Josiah Royce were colleagues and friendly critics of each other's thought for some twenty-five years in the Department of Philosophy at Harvard during a time which has been called the ‘Golden Period’ of American philosophy. James, the elder of the two, was responsible for bringing Royce to Harvard from the University of California in 1882. Thus began a philosophical exchange – ‘the battle of the Absolute’ – which revolved about Royce's defence of Absolute Idealism and James’ claim that such a ‘block universe’ is unable to do justice to the pluralistic, contingent and unfinished character of the cosmos and human life. Both men were deeply interested in religion as a dimension which belongs to the nature of life itself. Royce's approach took him in the direction of metaphysics and concern for the relation between certain basic religious ideas and a comprehensive theory of reality. James, by contrast, regarded metaphysical and theological articulation as secondary, because both are dependent on the elemental experiences of individual persons participating in the religious life. Royce's conception of religion was social through and through as is evidenced by his central conception of the Beloved Community. James, on the other hand, saw the locus of religion in the individual soul and always harboured the suspicion that ‘organized religion’ means religion at ‘second–hand’. The sequel will first treat each thinker separately and then pass on to the consideration of these points at issue between them.