Theories of the Tides 84 Measurement of a Terrestrial Degree 85 Geographical Positions 85 Arin 86 Arabic Exploration and Travel 87 IV THE SOURCES FOR THE PERIOD 1100–1250 A. D. 88 Introduction 88 Theological and Philosophical Works 89 Theological Works 89 Peter Abelard 89 Hugh of St. Victor 90 Hildegard of Bingen 90 Peter Lombard and Peter Comestor 91 The School of Chartres: Its Intellectual Independence 91 Bernard and Theodoric of Chartres 91 Adelard of Bath; Hermann the Dalmatian; Robert of Retines 92 Bernard Sylvester 93 William of Conches 93 Alexander Neckam 93 Translations from the Arabic; Works Written under Arabic Influence; Aristotelianism and Its Opponents 95 Adelard of Bath; Peter Alphonsi 95 John of Seville; Plato of Tivoli 96 “Marseilles Tables” and “Toledo Tables” 96 Robert of Retines; Hermann the Dalmatian; Daniel of Morley 97 Gerard of Cremona; John of Holywood (Sacrobosco) 97 Aristotelianism Introduced Through Arabic Works 98 Gerard of Cremona 99 Michael Scot 99 Aristotelianism in the Thirteenth Century 100 Opponents of Aristotelianism 101 William of Auvergne 101 Robert Grosseteste 101 Encyclopedic Works 102 “De Imagine Mundi” 103 Lambert’s “Liber Floridus”; Guido’s Encyclopedia 103 “Lucidarius” 104 Gervase of Tilbury 104 Jacques de Vitry 105