Constellations

A man should have three masculine friends older than himself, three of about his own age, and three younger. And he should have three older women friends, three of his own age, and three younger. These twice-nine friends I call his Constellation.... Seldom—perhaps never—are all eighteen roles filled at the same time. Vacancies occur; some live for years—or for a lifetime—with only one older or younger friend, or with none.... But we must remember that we also play a part in the Constellations of others—which is a partial replacement in our own.

—Thornton Wilder, Theophilus North, The Deer Park, p 310.