From error to truth, there is no gradual ascent. The passage is described by Croce as a kind of spiritual conversion: the erring spirit, fleeing from the light, must convert itself in a researching spirit, eager for light; pride must yield to humility; the narrow love for one's abstract individuality, widen and lift itself to an austere love, to an utter devotion to that which is above the individual, becoming Bruno's _eroico furore_, Spinoza's _amor Dei intellectualis_. In this act of love and enthusiasm, the spirit becomes pure thought and attains the truth, or, rather, transforms itself into truth. And the possession of truth is at the same time possession of its contrary, of error transformed into truth; to possess a concept is to possess it in the fulness of its relations, and therefore to possess, in the same act, all the ways in which that concept, for instance, of the æsthetic activity, is at the same time the concept of hedonism, intellectualism, empiricism, and so on. The two kinds of knowledge, that of truth and of its contrary, are inseparable: the concept is at the same time affirmation and negation. From this absolute possession of truth, we may distinguish a stage of research, which is not yet thought, but only the operation of the practical will creating certain conditions for thought. Seen in the light of this process, the series of errors through which a mind goes, when guided by a will to gather its materials and prepare itself to think, transforms itself into a series of attempts or hypotheses. An error is an error when there is a will to err; the hypothesis, however, into which the error is transmuted by the new will is not yet truth, and becomes truth only in the act of its verification; but it is no longer an error, because it does not affirm itself as truth, but only as a means or help for the conquest of truth.