Is there a circular relationship between trust and ethics? Is it possible to alter their relationship, changing the perception that social actors have of them? How has trust changed in the transition from modernity to post-modernity and how does it change in times of crisis? Starting from the epistemological assumption that progress in the social sciences is determined by the change in the theoretical horizon produced by “a reformulation of metaphysical assumptions” [1] and combining this path with the relational perspective, (...) according to which “not the facts, but the relationship between the facts is what requires analysis” [2], we will examine definitions, meanings, functions and relationships between trust and ethics. Following the theoretical logical method, we will understand that trust and ethical behaviour are particular forms of gift [3] that co-own each other. As such, they are ambivalent in nature and their circle can also produce dysfunctional outcomes that depend on the ability of social systems to modify collective perceptions through forms of communication, in the awareness that distrust constitutes an ineliminable and, paradoxically, preparatory element for the restoration of the trust circle. The relational circle between gift, trust, collective ethics and personal morality does not end with distrust, but changes in a contingent way, determining perverse effects: correct behaviour could produce, unintentionally, a disaster; incorrect actions could generate unforeseen positive effects.The perverse effects cannot be defined as exceptional - as is believed in the theory of rational choice - but recurrent because daily practices are marked by an intuitive, emotional and moralistic trust circle that prevails over logical reasoning, as ascertained by both relational theory and behavioural economics. Functionalist paradigms cannot engineer and optimise the performance of trust. [1] See J. Alexander's strong programme in S. Segre, Le teorie sociologiche contemporanee, Carocci, Rome, 2019, p. 12. It is not enough to observe reality, it is necessary to interpret it, taking into account theories and traditions whose foundations have a metaphysical character. [2] F. Ferrarotti, La sociologia come analisi critica della società, in R. Cipriani, Nuovo Manuale di Sociologia, Maggioli, Sant’Arcangelo di Romagna, 2018 p. 24. [3] The classical meaning in M. Mauss, Essai sur le don. Forme et raison de l'échange dans les sociétés archaïques, 1ª ed. 1925, revisited by G. Satta, L’ambiguità del dono. Note su dono, violenza e potere nell’ Essai di Mauss, in V. Rasini, Aggressività. Un’indagine polifonica, Mimesis, Milano 2011. (shrink)