“O no! it is an ever-fixed mark”William Shakespeare · Sonete · 1609 · Sonetul 116
Love is worth its stillness: a moving landmark can guide no ship.
The metaphor comes from navigation: the lighthouse or star does not move, and that is precisely why it is useful — the ship is the one in turmoil. The point is that true love is not affected by the storms its bearers pass through; its very immobility gives them direction. The mechanism is credibility: a shifting landmark can guide no one. A partner who stays the same in crisis becomes, literally, the point around which the other's life is organized.
Why it matters For couples in crisis: the value lies not in the intensity of good moments, but in not withdrawing when the other needs a landmark.