This mathematical point may lead us over to the discussion of the scientific methodology of al-Bīrūnī, surely one of the greatest mathematicians of the Middle Ages. To consider his work after that of Ibn al-Haytham will make it easier for us to select the essential features of his approach as a scientist which otherwise tend to get lost in the very extensive and variegated investigations, calculations and historical accounts that make up his major writings. And al-Bīrūnī has not reflected so intensively on his own method as did his great contemporary Ibn al-Haytham.

The contrast between the two contemporary scientists is quite obvious from the beginning: While Ibn al-Haytham, as he himself informs us, endeavoured systematically to absorb and further develop the Aristotelian treasure of knowledge, scientific work seems to have come quite spontaneously to al-Bīrūnī, almost as the natural outflow of...