Introduction: Institutions and sources: The sources: twelfth-century (re)discovery, thirteenth-century effects ; The institutional context - Consolidation: Anselm of Canterbury (1033-1109) ; From 1100 to 1200: Peter Abelard ; Gilbert of Poitiers ; Bernard of Clairvaux ; The Victorines ; Peter Lombard - Revolution: From 1200 to 1277: Robert Grosseteste ; William of Auvergne ; Alexander of Hales ; Albert the Great ; Bonaventure ; Roger Bacon ; The Paris arts faculty ; Thomas Aquinas (c.1225-74) - Innovation: From 1277 to 1300: Correctorium literature ; Henry of Ghent ; Peter Olivi ; Giles of Rome ; Godfrey of Fontaines ; Duns Scotus (c. 1266-1308) - Simplification: William of Ockham (c. 1287-1347) ; From 1310 to 1350: Durand of St Pourcain (and Hervaeus Natalis) ; Peter Auriol ; Ockham's Oxonian contemporaries, followers, and opponents ; Nicholas of Autrecourt ; Epilogue: Restrospection: John Wyclif (c.1330-84) The High Middle Ages were remarkable for their coherent sense of 'Christendom': of people who belonged to a homogeneous Christian society marked by uniform rituals of birth and death and worship. That uniformity, which came under increasing strain as national European characteristics became more pronounced, achieved perhaps its most perfect intellectual expression in the thought of the western Christian thinkers who are sometimes called 'scholastic theologians'. This book offers the first focused introduction to these thinkers based on the individuals themselves and their central preoccupations.