He was an Egyptian, born around the middle of the fourth century, and he went out to the desert of Scetis as a young man with his brothers. Anoub was the eldest, Poemen the middle, and Paisios the youngest, and there were others, and the family lived as a small community under one roof, which is the setting of a great many of the stories about him.

The tradition preserves the visit of their mother. She came out to the desert to see her sons and they would not come out to her, and she waited at the door of the church, and Poemen spoke to her through the closed door: that if she saw them here she would not see them there. She went away comforted, which is the detail that keeps the story from being merely hard.

He was not an extremist. The desert produced men who competed at fasting and men who ruined their bodies, and Poemen is the father the sources use to correct them. He is on record telling monks to eat, telling them to sleep, telling a man who had tortured himself into a stupor that this was no achievement, and insisting over and over that the measure of a monk is what happens to his heart, not what happens to his stomach.

Around the year four hundred and seven the Mazices, desert raiders from the west, came down on Scetis and destroyed it. Monks were killed, the cells were emptied, and the great settlement that had grown up around Macarius scattered. Poemen and Anoub led a small group out and came to Terenuthis on the Nile, where they took shelter in an abandoned pagan temple, and it is there that the tradition sets the trial of the stone idol: that Anoub, to teach the brothers, stoned the face of the statue every morning and asked its pardon every evening, and then asked them whether the stone had grown angry or ashamed, and told them that unless a man can be insulted and honored and remain what he was, he cannot live with brothers.

Poemen lived on into old age and, if the tradition's dates are right, to a very great age indeed. His cell became a place people traveled to. Bishops came. Anchorites came. Monks came with the questions monks actually have, and the answers were written down by whoever was standing there, which is why so many of them survive in the raw and unedited form of a real conversation.

His theme, said a hundred ways, is that a man must weep for his own sins and not for his neighbor's. When brothers came to him about someone else's fall, he moved the subject. When they came to him about their own, he stayed on it for as long as they wanted. He is severe with judgment and gentle with the person judged, and the combination is the reason the desert called him great.

The second theme is watchfulness: guarding the thoughts at the point of entry rather than fighting them after they have settled, keeping the tongue, keeping the eyes, keeping the will. He treated the interior life as a discipline with technique in it, not as a mood, and that treatment is what passed from him into the whole later hesychast tradition, through John Cassian, who visited Egypt in these very years, and through the Philokalia after him.

The third is discernment, which he ranked above zeal and would not let anyone shortcut. He is the father who says, in one form or another and constantly, that a good thing done at the wrong measure is not a good thing.

The Church keeps his memory on the twenty seventh of August, calling him Poemen the Great, or Pimen in the Slavonic usage. He is the pattern of the elder in the Orthodox tradition: no office, no writings, no institution, and four hundred years of monks quoting him.