revealed religions, reciting the claims of Zoroastrianism, Christianity and Judaism. In the early 11th century, the Islamic scholar Abū Rayhān Bīrūnī wrote detailed comparative studies on the anthropology of religions across the Middle East, Mediterranean and especially the Indian subcontinent. Biruni's anthropology of religion was only possible for a scholar deeply immersed in the lore of other nations. He carried out extensive, personal investigations of the peoples, customs, and religions of the Indian subcontinent, and was a pioneer in comparative religion and the anthropology of religion. According to Arthur Jeffery, "It is rare until modern times to find so fair and unprejudiced a statement of the views of other religions, so earnest an attempt to study them in the best sources, and such care to find a method which for this branch of study would be both rigorous and just." Biruni compared Islam with pre-Islamic religions, and was willing to accept certain elements of pre-Islamic wisdom which would conform with his understanding of the Islamic spirit. In the introduction to his Indica, Biruni himself writes that his intent behind the work was to engage dialogue between Islam and the Indian religions, particularly Hinduism as well as Buddhism. Biruni was aware that statements about a religion would be open to criticism by its adherents, and insisted that a scholar should follow the requirements of a strictly scientific method. According to William Montgomery Watt, Biruni "is admirably objective and unprejudiced in his presentation of facts" but "selects facts in such a way that he makes a strong case for holding that there is a certain unity in the religious experience of the peoples he considers, even though he does not appear to formulate this view explicitly." Biruni argued that Hinduism was a monotheistic faith like Islam, and in order to justify this assertion, he quotes Hindu texts and argues that the worship of idols is "exclusively a characteristic of the common people, with which the educated have nothing to do." Biruni argued that the worship of idols "is due to a kind of confusion or corruption." According to Watt, Biruni "goes on to maintain that in the course of generations the origin of the veneration of the images is forgotten, and further that the ancient legislators, seeing that the Veneration of images is advantageous, made it obligatory for the ordinary. He mentions the view of some people that, before God sent prophets,