necessary to construct a bridge to join the two parts of my book. A bull of Pope Gregory XI at once directed me to trace the political system of Wycliffe back to Marsiglio of Padua and to William Ockham; and an exposition of John of Salisbury's views, in the setting of the type of opinion which he represented, was introduced to form a counter-piece to my summary of the opposed doctrine. On my return to England in the summer of 1883 I applied myself to filling in the gaps in my essays, which needed a larger library than could be found at Zurich, and to completing the last chapters. In the following year I paid a long visit to Vienna in order to examine the Wycliffe manuscripts in the imperial library, and in the course of the autumn my book was published.
The title which I gave to it was Illustrations of the History of Medieval Thought in the Departments of Theology and Ecclesiastical Politics. I have now abbreviated it and at the same time expanded its scope. In revising the text I have specially to thank my friend the Rev. F. E. Brightman, D.D., for his great kindness in reading the sheets and suggesting a large number of improvements both in form and matter. In two chapters only, iv and v, have I made extensive alterations. These were required by the new evidence that has been brought to light concerning Bernard of Chartres, whom I have been compelled to distinguish from Bernard Silvestris,[1] and by the discovery of Abailard's early work de Trinitate in 1891.[2] But changes and corrections of less importance have been made
