The conditions of a solitary bird are five:
The first, that it flies to the highest point;
the second, that it does not suffer for company,
not even of its own kind;
the third, that it aims its beak to the skies;
the fourth, that it does not have a definite color;
the fifth, that it sings very softly.
– San Juan de la Cruz, Dichos de Luz y Amor