One needs only to be old enough in order to be as young as one will.  From the top of this Abbey Church one looks across the bay to Avranches, and towards Coutances and the Cotentin,—­the Constantinus pagus,—­whose shore, facing us, recalls the coast of New England.  The relation between the granite of one coast and that of the other may be fanciful, but the relation between the people who live on each is as hard and practical a fact as the granite itself.  When one enters the church, one notes first the four great triumphal piers or columns, at the intersection of the nave and transepts, and on looking into M. Corroyer’s architectural study which is the chief source of all one’s acquaintance with the Mount, one learns that these piers were constructed in 1058.  Four out of five American tourists will instantly recall the only date of mediaeval history they ever knew, the date of the Norman Conquest.  Eight years after these piers were built, in 1066, Duke William of Normandy raised an army of forty thousand men in these parts, and in northern France, whom he took to England, where they mostly stayed.  For a hundred and fifty years, until 1204, Normandy and England were united; the Norman peasant went freely to England with his lord, spiritual or temporal; the Norman woman, a very capable person, followed her husband or her parents; Normans held nearly all the English fiefs; filled the English Church; crowded the English Court; created the English law; and we know that French was still currently spoken in England as late as 1400, or thereabouts, “After the scole of Stratford atte bowe.”  The aristocratic Norman names still survive in part, and if we look up their origin here we shall generally find them in villages so remote and insignificant that their place can hardly be found on any ordinary map; but the common people had no surnames, and cannot be traced, although for every noble whose name or blood survived in England or in Normandy, we must reckon hundreds of peasants.  Since the generation which followed William to England in 1066, we can reckon twenty-eight or thirty from father to son, and, if you care to figure up the sum, you will find that you had about two hundred and fifty million arithmetical ancestors living in the middle of the eleventh century.  The whole population of England and northern France may then have numbered five million, but if it were fifty it would not much affect the certainty that, if you have any English blood at all, you have also Norman.  If we could go back and live again in all our two hundred and fifty million arithmetical ancestors of the eleventh century, we should find ourselves doing many surprising things, but among the rest we should pretty certainly be ploughing most of the fields of the Cotentin and Calvados; going to mass in every parish church in Normandy; rendering military service to every lord, spiritual or temporal, in all this region; and helping to build the Abbey Church at Mont-Saint-Michel.  From the roof of the Cathedral of Coutances over yonder, one may look away over the hills and woods, the farms and fields of Normandy, and so familiar, so homelike are they, one can almost take oath that in this, or the other, or in all, one knew life once and has never so fully known it since.