Miguel de Unamuno

Spiritual Love is born of sorrow. . . .
For men love one another with spiritual love
only when they have suffered the same sorrow together,
when through long days they have ploughed the stony ground
buried beneath the common yoke of a common grief.
It is then that they know one another and feel one another
and feel with one another in their common anguish,
and so they pity one another and love one another.
--- Miguel de Unamuno