A second opportunity was presented by the series of treatises, which, from Machiavelli onward, had come to conceive of politics as a fact independent of morality, elaborating in particular those precepts and maxims of the "reason of state," of which we have already had occasion to expose the empirical character. But however empirical they were, those mental products gave rise to the problem of the relations between morals and politics, that is to say, as to whether the two terms could be considered as immediately identifiable. The thought of Machiavelli, in particular, constituted an enigma that all attempted to interpret in the most different ways, most by vituperating, some by defending it with strange reasons (Spinoza was among the defenders[13]), though they never succeeded in freeing themselves from its difficulties, for to that end would have been necessary the understanding of the spiritual value of the utilitarian will, even if amoral. It was only when this difficult concept was to some extent caught sight of (by De Sanctis) that Machiavelli appeared at once justified and criticized; but while that concept remained obscure, the point of view of Machiavelli was never attained and the work was condemned for reasons of a moralistic character (Villari).[14] Kant, too, in his work on _Perpetual Peace,_ treated the problem of the relations between morality and politics, affirming that no disagreement is possible between them, unless by politics is meant a _doctrine_ of prudence, that is, "a theory of maxims for the selection of the means best adapted for the objects of individual advantage; that is, when the existence of morality is not altogether denied."[15] Here too, he was right, when he claimed that concrete political actions should be submitted to morality; but, on the other hand, he did not perceive that submission and identity presuppose a previous independence and distinction. [Sidenote: _The doctrine of the passions._]