His main focus is in the history of medieval and early modern science, especially physical science and the relationship between religion and science.

New historical research has also shown that medieval Christians were not generally opposed to scientific investigation and revealed the extent and variety of medieval science.

He developed the concept of impetus, the first step toward the modern concept of inertia, and an important development in the history of medieval science.

Here "hot, cold, moist, and dry," the four elements in medieval science, contend in confusion.

Professor Grant was twice chair of his department (1973-1979; 1987-1990) where he taught courses on medieval science, natural philosophy and science and religion.

Alchemy - a medieval science, the object of which was to try to transmute base metals into gold.

The medieval "science of weights" (i.e., mechanics) owes much of its importance to the work of Jordanus.

Duhem's view has been extremely influential in the historiography of medieval science, and opened it up as a serious academic discipline.

As a medievalist, he is best seen as a historian of technology but has also written interesting syntheses of medieval science, from a comparative perspective.

It is true that, in most other cases, there was a certain limitation to the data of medieval science; but this certainly had nothing to do with medieval religion.