The central theme of this volume lies in the medieval consciousness of mathematics, and the variety of strategies adopted to apply it in other areas, notably natural philosophy. In diachromic terms, Dr Molland considers ways in which ancient mathematics (particularly geometry) was assimilated in the Middle Ages, and how it was radically transformed in the 17th century, especially by Descartes. A pervasive concern is with ideas of scientific progress: the author argues that medieval commentatorial and disputational modes encouraged probing attitudes to existing knowledge, aimed at deepening individual understanding, rather than more aggressive endeavours to advance public knowledge characteristic of later periods. What brought about this change is the subject of several studies here; others form more specifically on individual scholars, in particular the important figure of Roger Bacon.