Saint Dermot opened a monastery sometime early in the 6th century on the island of Innis-Closran, Ireland; he died in AD 542, which puts him in the window of the great flourishing of Celtic Christianity between Saint Patrick and the Council of Whitby. Apparently he was a teacher, for he trained Saint Kiernan of Clonmacnoise. Seems closely connected with the concept of justice, was a noted teacher, preacher and spiritual director.
This is not much to go on. Here’s for trying:
Courageous Dermot, spiritual father,
director of Kiernan of Clonmacnoise:
in your tiny church, in any weather,
you were the great teacher of many boys
learning rhetoric and geometry;
by candle and sunshine they learned to write,
draw, play music… and such astronomy
as could be discerned in the Irish night.
They grew to be chieftains, and brehons fair —
thus did you earn your epithet, “the Just”.
Your students learned ethics, and judged with care,
logic, and mercy, as good leaders must.
Thus do we praise you, under winter stars,
who taught self-discipline in carefree hours.
Not too bad. I was trying to get across all the traditional seven liberal arts, but I got distracted by the mental image of Dermot’s students in a cold Irish monastery (on an island in a lake! brrr!) learning to draw Celtic knot work, and that wound up taking precedence over grammar; and law was important in Irish society as it moved into the Christian era, so I imagined the students being sons of local nobility becoming brehons, which was a kind of Irish common-law judge.
One of the things that I hope comes through in this piece is how much of the old Druidic world survived into the Christian era. This guy Dermot is as much pagan as Christian, in my mind. He’s interested in teaching people to think, to act from rationality and reason as much as from Christian vision, as I see it. I think that’s the reason so little information about him really survives.