The article has the aim to show that Kant’s “standard” conception of the highest good does not represent his last word about the problem. Kant moves from a conception of the highest good close connected with the metaphysical tradition and with the aim of a new, moral justification of traditional metahysical concepts such as God and immortality of the soul. This view does find many difficulties and oscillations in the Critiques, looking for different formulations of a moral “proof” for the (...) metaphysical concepts, grounded upon the need of justice and of a rational solution to the question of theodicy. The failure of this project is apparent with the essay on theodicy. In the last decade of Kant’s intellectual activity, the expression “highest good” occurs few times and the concept looses its systematic relevance, as shown by the last works up to the Opus postumum. (shrink)