but also me = non-me (unity in difference), for both find their synthesis in the real unity of the concrete and the abstract, of the subject thinking and the object thought. Identity of history and current events The transcendental feature of thought is such that my present thought of now includes the past and the future : the now, the present hour of thought is not between before and after, but encompasses the totality of time , and therefore it is eternal , an eternal becoming. Gentile challenges Croce's distinction between "history that is made" and "history that is thought," between "res gestae" and "historia rerum gestarum," asserting the contemporaneity of history, which "should not be confused with Vico's, which leaves out of itself one that unfolds in time : one where our eternal is the same time considered in the actuality of the spirit". Historical knowledge consists in the reduction of the multiple to the concrete unity of the act, a synthesis of the opposing theses that conceive the spirit now as a historical dialectic, now as an a-historical eternity. The identity of philosophy and history is therefore supported by Gentile in a much more radical way than Croce: Evolution of the Spirit The history of the spirit as an eternal presence of itself to itself is seen by Gentile as a progressive awareness of actualism itself. Reforming the idealism of Hegel, he intends to purge it of both the developments going in the direction of Platonism attempted by the Hegelian Right and the Materialist results of the Hegelian Left. According to Gentile, Plato's mistake is to assume the transcendence of ideas with respect to thought, remaining in a dualism of mind-matter based abstractly on a being, or a matter, presupposed to the thought, which is the characteristic feature of Greek philosophy. Christian philosophy had the merit of overcoming the intellectualistic position of the Greeks, their materialistic representation of the world, through the arduous effort to spiritualize reality, while still affirming the transcendence of the Spirit. This will later be resolved by Spinoza in the immanent unity of substance, which Gentile intends to transform into an immanentism of a subjectivistic and spiritualistic kind. The cogito ergo sum of Descartes is a fundamental step in the journey of Western philosophy toward the self-consciousness of the actualist principle, as are George Berkeley's famous adage esse est percipi and Kant's a priori