EVIDENCE FROM EARLY IRISH LITERATURE:
There are many passages in the oldest Irish literature, both secular and religious, which state that the Irish had books before the introduction of Christianity. In a memoir[12] of St. Patrick written in the seventh century Muirchu Maccu Machteni relates how during the contest of the saint with the druids—the learned men of the time—the High King Laoghaire proposed that one of St. Patrick’s books and one belonging to the druids should be cast into the water to see which would come out uninjured—a kind of ordeal. Here it will be noticed that Muirchu’s statement embodies a tradition which was old in the seventh century. The same story is told in the Tripartite Life of St. Patrick.[13] Both the Irish bardic tales and the oldest existing lives of St. Patrick agree in stating that he found in the country both literary and professional men—all pagans—druids, poets and antiquarians or historians,[14] as well as an elaborate code of laws.[15]
Although no Irish document has been preserved which dates earlier than the seventh century, there is ample intrinsic evidence that the earliest existing documents were copied from manuscripts which go back a century or two earlier and these again may have recorded the traditions of a still earlier period. Authorities are agreed that after the establishment of Christianity in the fifth century the Irish scholars committed to writing not only the laws, bardic historical poems, &c. of their own time, but those which had been preserved from earlier times whether traditionally or otherwise.[16] In a subsequent chapter reference will be made to a common practice of the Irish monks, namely that of making marginal and interlinear glosses on the classical writings they were studying, copying, or teaching. For the present it is sufficient to note that even in the case of the earliest of the seventh century glosses the written language was fully developed and cultivated, with a polished phraseology and an elaborate and systematic grammar having well established forms for its words and for all its rich inflections. To the linguistic student it is inconceivable how much a complete and regular system of writing could have developed in the period which had elapsed from the introduction of Christianity in the fifth century until the general spread of Christian learning in the seventh. Such a period would be much too short, especially when it is recollected that early Irish literature had its roots not in Christianity but in the native learning which was the main, and almost the sole, influence in developing it. This consideration points clearly to the conclusion that native learning was carefully and systematically cultivated before the introduction of Christianity.
Again, Irish poetry owes its development solely to the Lay Schools.[17] It had complicated prosody—with numerous technical terms[18] all derived from the Irish language. These vernacular terms used in Irish grammar contrast strikingly with the terms used to designate the offices and ceremonies of Christianity which were almost all derived from Latin.[19] All this would go to prove that Irish prosodial rules and technical terms, and of course Irish poetry itself, were fully developed before the introduction of Christianity.