Reduction in this sense is not deduction. Rather, it resembles induction. In the last resort, no decisive grounds can be offered for trusting; trust results from exceeding existing information. It is, as Simmel pointed out, a blending of knowledge and ignorance. Although the one who trusts is never at a loss for reasons and is quite capable of giving an account of why he shows trust in this or that case, the point of such reasons is really to uphold his self-respect and justify him socially. They prevent him from appearing to himself and others as a fool, as an inexperienced person illadapted to life, in the event of his trust being abused. At most, they are brought into account for the placing of trust, but not for trust itself. Trust remains a risk.

XREF: Connects to Simmel's concept of trust as a blend of knowledge and ignorance — echoes themes about the limits of rational justification.

Niklas Luhmann, Trust and Power, loc. 150