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. This 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.