His most important work on the history of science was, however, research which showed that the period from 1200 onwards was not a period when science had been ignored.
Ang kanyang mga pinaka-mahalagang gawain sa kasaysayan ng agham ay, gayunpaman, pananaliksik kung saan ay nagpakita na ang panahon mula 1200 pasulong ay hindi isang panahon kapag nagkaroon na agham ay winalang-bahala.