This study examines the changes which took place in the understanding of ‘religion’ and ‘the religions’ during the Enlightenment in England, the period when the decisive break with Patristic, Medieval and Renaissance notions of religion occurred. Dr Harrison’s view is that the principles of the English Enlightenment not only made a special contribution to our modern understanding of what religion is, but they pioneered, in addition, the ‘scientific’, or non-religious approach, to religious phenomena. During this period a crisis of authority in the Church necessitated a rational enquiry into the various forms of Christianity, and in addition, into the claims of all religions. This led to a concept of ‘religion’ (based on ‘natural’ theology) which could link together the apparently disparate religious beliefs and practices found in the empirical religions.