Duns Scotus, along with Thomas Aquinas and William of Ockham, was one of the three most talented and influential of the medieval schoolmen, and a highly original and creative thinker. Natural philosophy, or physics, is one of the areas of his system which has not received detailed attention in modern literature. But it is important, both for understanding Scotus's contributions in theology, and in tracing some important developments in the basically Aristotelian world-view which Scotus and his contemporaries espoused. The book contains detailed discussion and analysis of Scotus's accounts of the nature of matter; the structure of material substance; mass; the nature of space, time, and motion; quantitative and qualitative change; and the various sorts of unity which can be exhibited by different kinds of whole. It also includes discussion of Scotus's accounts of chemical composition, organic unity, and nutrition. Scotus's views on these matters are philosophyically sophisticated, and often highly original.