"As European powers expanded into Asia, knowledge of its religions became more soundly based. Changes in European thought also led to some receptivity to ideas from non-Christian religions. In the eighteenth century, the Enlightenment’s emphasis on ‘reason’ and ‘science’ weakened reliance on authoritative ‘revelation’ in religious matters, and a number of people thought that they saw a ‘natural religion’ held in common by people of all cultures, though best expressed in Christianity. In the nineteenth century, advances in geology and Biblical studies led to a weakening of Biblical literalism, and the concept of biological evolution seemed, to many, to cast doubts on the ‘revealed’ Christian account of creation. In this context, the idea of making a ‘scientific’, ‘comparative’ study of all religions came to be advanced."