In a 1989 article in the European Journal of Sociology on the changing conceptions of friendship through history, Allan Silver comments on the relationship between uncertainty and trust:

“Uncertainty about others cannot be eliminated on purely experiential grounds. Trust is meaningful precisely because others retain their capacity to act against our interests or turn indifferent to them, and because a situation may arise in which they may be tempted to do so . . . . Trust copes with uncertainty by a distinctive mechanism: acting as if the other will not let us down although the other cannot but have the capacity to do so. In transcending the unavoidable possibility of betrayal, personal trust achieves a moral elevation, lacking in contractual or other engagements enforced by third parties. Trust takes on a certain moral urgency because it affirms the impossibility of betray despite its existential possibility.”

He notes another dimension of trust in the Roman notion of fides :

“The act of trust involved in fides implies the certainty of remuneration - loyalty and faithfulness secures the benefit of that which has been entrusted. Fides does not refer to much to an estimate of another’s moral qualities, as in the modern expression, ‘I have faith in you.’ Rather, it is a capacity or resource which one can, as it were, invest in another; once invested, fides creates credit with the other. The transaction is objective in that fides is a resource available for allocation in competitive systems of alliance and cooperation It obligates another, in receiving one’s fides , to extend trust, not merely belief, but concrete resources to be made available in determinate circumstances. Indeed, specific and practical imperatives run through historical accounts of friendships in times past.”