Gentile's philosophy merits the attention of every serious thinker, for it presents the doctrine that reality is spiritual in a more uncompromising form than is to be found elsewhere, and claims to solve on this principle all the great problems that have beset the history of metaphysic. His own name for it is Absolute or Actual Idealism (Idealismo assoluto or attuale). For Gentile, nothing is real but the Spirit, and by the Spirit he means the pure act of self-conscious thinking. “The subject that conceives itself in conceiving All is the reality itself.” In the act of conscious thinking, the Spirit is present in its entirety as subject (Io universale, transcendentale, assoluto); generating therein by its own creative spontaneity a world of objects, and resolving the products of this act of objectification into the womb that gave them birth. In this immanent dialectic–pure subject (thesis), pure object (antithesis), subject-object (synthesis)–lies the rhythmic life-history of the Spirit. “Our doctrine,” writes Gentile, “is the theory of the Spirit as act which posits its object in a multiplicity of objects, resolving their multiplicity and objectivity in the unity of the subject itself.” For such a doctrine, transcendence is the enemy, the Goliath whom Gentile has gone forth to slay. He confronts us, on almost every page of his writings, with an ineluctable dilemma. Either a philosophy of sheer immanence, or reality is unknowable.