If the function of those who want to become a function for another is not desired, the relationship hollows for there remains nothing more than uselessness.

Joy and desire go together in the stronger, who wants to transform something into a function of himself; joy and the wish to be desired go together in the weaker, who wants to become a function. Compassion is essentially the former, a pleasant stirring of the drive to appropriate at the sight of the weaker; however, we must still keep in mind that ‘strong’ and ‘weak’ are relative concepts.

Nietzsche, The Gay Science, translated by Josefine Nauckhoff