It seems that personal trust is only formed where it is needed. This is the case – even today – if the individual personality takes on a social-structural relevance, if the configuration of interaction relationships is arranged in the social system in such a way that it can only be arranged thus and now has to be restructured after that individual ceases to be involved.

DEFINE: Clarifies the specific social-structural conditions under which personal trust forms — it is not spontaneous but tied to the irreplaceable role an individual plays in a configuration of interactions.

Niklas Luhmann, Trust and Power, loc. 204