But to reach that degree he was to prove for himself, purity of learning, purity of mouth (from satire), purity of hand (from bloodshed), purity of union (in marriage), purity of honesty (from theft), and purity of body (having but one wife). With the Celts, therefore, learning constituted a kind of priesthood. These were his moral qualifications. His scientific attainments require a little longer consideration, as they form the chief object we have in view. They may at the outset be stated in a few words. The ollamh was "a man who had arrived at the highest degree of historical learning, and of general literary attainments. He should be an adept in royal synchronisms, should know the boundaries of all the provinces and chieftaincies, and should be able to trace the genealogies of all the tribes of Erin up to the first man.--(Prof. Curry, Lecture X.) Caesar had already told us of the Druids, "Si de hereditate, si de finibus controversia est iidem decernunt." In this passage he gives us a glimpse of a system which he had not studied sufficiently to embrace in its entirety. The qualifications of an ollamh which we have just enumerated, that is to say, of the highest doctor in Celtic countries, already prove how their literature grew out of the clan system. The clan system, of which we shall subsequently speak more at length, rested entirely on history, genealogy, and topography. The authority and rights of the monarch of the whole country, of the so-called kings of the various provinces, of the other chieftains in their several degrees, finally, of all the individuals who composed the nation connected by blood with the chieftains and kings, depended entirely on their various genealogies, out of which grew a complete system of general and personal history. The conflicting rights of the septs demanded also a thorough knowledge of topography for the adjustment of their difficulties. Hence the importance to the whole nation of accuracy in these matters, and of a competent authority to decide on all such questions. But in Celtic countries, more than in all others, topography was connected with general history, as each river or lake, mountain or hill, tower or hamlet, had received a name from some historical fact recorded in the public annals; so that even now the geographical etymologies frequently throw a sudden and decisive light on disputed points of ancient history. So far, this cannot be called a literature; it might be classed under the name of statistics, or antiquarian lore; and if their history consisted merely of what is contained in the old annals of the race, it would be presumptuous to make a particular alllusion to their literature, and make it one of the chief characteristics of the race. The annals, in fact, were mere chronological and synchronic tables of previous events.