All relations with others are thus ultimately mere stations along the road by which the ego arrives at its self. This is true whether the ego feels itself to be basically identical to these others because it still needs this supporting conviction as it stands alone upon itself and its own powers, or whether it is strong enough to bear the loneliness of its own quality, the multitude being there only so that each individual can use the others as a measure of his incomparability and the individuality of his world.

XREF: Connects to ego psychology and developmental self-theory — echoes how individuation in Jungian and psychoanalytic thought treats others as foils for self-becoming.

Georg Simmel, on individuality and social…, loc. 537