2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84790In this paper, through a criticism of what we call the paradigmatic view of thermodynamics, we aim at showing a new perspective attained in this matter. The generalization of heat as internal energy (generalization of the kinetic energy concept of heat) permits the generalization of the Kelvin postulate: "It is impossible, without another effect, to convert internal energy into work" (no reference to heat or to heat reservoir).18 pages, 1 figureGeneral Physicstext