Philosophical introspection--Affirmation of the practical activity--The category of feeling--The theoretical activity as the antecedent of the practical--Identity of intention and volition--Identity of volition and action--The practical judgment: philosophy and psychology --The problem of free will: liberty and necessity--Croce's solution in the context of his philosophy--The practical value: good and evil--The unreality of evil, and the function of ideals--The sanction of evil--The volition and the passions--The empirical individuality--Development and progress. The reality of the practical activity as distinct from the theoretical activity, of will as distinct from knowledge, can never be proved through the naturalistic method of psychology, by merely pointing to a class of facts--actions--different from another class of facts--thoughts. The so-called action manifests itself, at a closer analysis, as infinitely complex and rich in purely theoretical elements; the so-called thought, as partly at least a work of the human will. The concrete life of the spirit is always both practical and theoretical, and the distinction we are looking for is an ideal distinction, to be ascertained by the method of philosophical, not psychological, introspection; by the direct witness of consciousness, and by the deduction of its function in the concept of the spirit, or of reality, as a whole. The complete affirmation of a form, or grade, of spiritual activity is the philosophy of that form, and of its relations with the others; in this case, the philosophy of the practical, or of will. It is hardly necessary, at this stage of our exposition, to observe that the philosophy of the practical will not be practical philosophy, a collection of rules for the attainment of the useful and the good, any more than the philosophy of art is a collection of æsthetic precepts: it will be a purely formal science, a universal concept, the content of which is the infinite wealth of the individual determinations of the will, the history of the practical activity. In the following chapter we shall deal more particularly with the two forms of the practical activity, economic and ethic, corresponding to the two forms of the theoretical, æsthetic and logic. Here we shall consider the undifferentiated practical activity, first, in its relations, and then, in its internal dialectic. The contents of this chapter are, therefore, intended as applying both to economics and ethics, to the useful and to the good.