The celebrated masterpiece by Jheronimus Bosch entitled The Garden of Earthly Delights (1490-1500, Madrid, Museo Nacional del Prado) has been considered here as an exemplary case study to highlight how a work of art, in order to be truly effective in aesthetic and communicative terms, needs to censor its most didactic and merely narrative part, in order to make room for “the secret” that it conceals or that it wants to pretend to conceal. The aim of the paper is to show how this secret, if there really is one, does not lie so much in “what” the central panel depicts, but in “how” it functions or “acts” in relation to the activation and control of the observer’s imagination, be he believer or layman, art specialist or non-specialist. To pursue this objective, an original hermeneutic model has been adopted, defined as the iconological machine, in the wake of the “mythological machine” elaborated by Furio Jesi in the 1970s.