The author has sought throughout to put all the information, which he could collect in reference to his subject, in a popular and attractive form. At the same time he has spared no pains to consult all the available authorities both ancient and modern; and he has always gone to the original sources, whenever it was possible to do so. He does not pretend to have avoided all mistakes in matters of fact, nor to be quite free from errors in matters of opinion. But he can say that he has honestly done his best to make the study of this portion of our Celtic history interesting and profitable to the general reader. And there is no doubt that the study of the holy and self-denying lives of our ancient Saints and Scholars will exercise a purifying and elevating influence on the minds of all, but more especially of the young; will teach them to raise their thoughts to higher things, and set less store on the paltry surroundings of their daily life. With the single exception of Iona, which may be considered as an Irish island, this volume deals only with our Monastic Schools at home. Irishmen founded during this period many schools and monasteries abroad; but it would require another volume to give a full account of those monasteries and their holy founders. There are many friends to whom we owe thanks for assistance; but we have reason to believe that they would prefer not to have their names mentioned in this preface. In conclusion, we have only to add, that these pages have not been written in a controversial spirit; because in our opinion little or nothing is ever to be gained by writing history in a spirit of controversy, which tends rather to obscure than to make known the truth. It is better from every point of view to let the facts speak for themselves; and hence not only in quoting authorities, but also in narrating events, we have, as far as possible, reproduced the language of the original authorities. A few of the papers here published have appeared in the _Irish Ecclesiastical Record_, but they are now presented in a more popular form. ✠ JOHN HEALY, D.D. PALMERSTON HOUSE, PORTUMNA, _May, 1890_. [Gaelic] "May the tongue of Sage and Saint be lasting." TABLE OF CONTENTS. CHAPTER I. PAGE STATE OF LEARNING IN IRELAND BEFORE ST. PATRICK. I.--THE DRUIDS 1 Learning of the Druids 1 Religious Worship 2 Sacrifice of Human Victims 3 Worship of the Elements 3 Enchantments 4 Acquaintance with Letters 4 Sun-Worship 5