The twenty studies included here reflect three particular aspects of Leonard Boyle’s remarkable impact on teaching and scholarship. His abiding interest in the early history and architecture of the basilica of San Clemente in Rome forms the focus of Part I; his profound contribution to the theory and practice of palaeography is reflected in Part II; and his creative work on clerical education, pastoral care, and the Dominican Order, inspires Part III. In all these areas, Fr Boyle combined remarkable attention to detail with the humane ability to bring clarity to complex issues. This book commemorates his inspiration, but also reflects his favourite maxim, derived from the twelfth-century teacher-theologian, Hugh of St-Victor, to ‘Learn everything’, for ‘afterwards you will find that nothing is superfluous.’ The fourth section is devoted to Fr Leonard as friend, scholar, and Prefect of the Vatican Library, and it ends, fittingly, with what may be regarded as his own scholarly valediction, ‘St Thomas Aquinas and the Third Millennium’.