Can one identify the intellectual tools that made progress possible? I think so. The first is a belief in “discovery”, in the very possibility of intellectual progress. There was no such belief, there were not even words meaning “discovery” and “progress”, before the discovery of America which shattered the long-established conviction that there was no important new knowledge to be had. Moreover the discovery of the New World was the achievement of semi-educated sailors — it brought about a new cooperation between intellectuals and practical men, a cooperation particularly fostered by the mathematicians who taught the skills of navigation and cartography and who had long believed in the importance of useful knowledge.