What Fichte means by freedom may be best explained by its opposition to instinct. A man acting instinctively may be acting quite reasonably, in a way which any one fully conscious of all the implications and consequences of the action would judge to be reasonable. But in order that his actions should be free he must himself be fully conscious of all those implications and consequences. It follows that the end of mankind upon earth is to reach a state in which all the relations of life shall be ordered according to reason, not instinctively but with full consciousness and deliberate purpose. This end should govern the ethical rules of conduct, and it determines the necessary stages of history. It gives us at once two main periods, the earliest and the latest: the earliest, in which men act reasonably by instinct, and the latest, in which they are conscious of reason and try to realise it fully. But before reaching this final stage they must pass through an epoch in which reason is conscious of itself, but not regnant. And to reach this they must have emancipated themselves from instinct, and this process of emancipation means a fourth epoch. But they could not have wanted to emancipate themselves unless they had felt instinct as a servitude imposed by an external authority, and therefore we have to distinguish yet another epoch wherein reason is expressed in authoritarian institutions to which men blindly submit. In this way Fichte deduces five historical epochs: two in which progress is blind, two in which it is free, and an intermediate in which it is struggling to consciousness. [Footnote: First Epoch: that of instinctive reason; the age of innocence. Second: that of authoritarian reason. Third: that of enfranchisement; the age of scepticism and unregulated liberty. Fourth: that of conscious reason, as science. Fifth: that of regnant reason, as art.] But there are no locked gates between these periods; they overlap and mingle; each may have some of the characteristics of another; and in each there is a vanguard leading the way and a rearguard lagging behind. At present (1804) we are in the third age; we have broken with authority, but do not yet possess a clear and disciplined knowledge of reason. [Footnote: Three years later, however, Fichte maintained in his patriotic Discourses to the German Nation (1807) that in 1804 man had crossed the threshold of the fourth epoch. He asserted that the progress of "culture" and science will depend henceforward chiefly on Germany.] Fichte has deduced this scheme purely a priori without any reference to actual experience. "The philosopher," he says, "follows the a priori thread of the world-plan which is clear to him without any history; and if he makes use of history, it is not to prove anything, since his theses are already proved independently of all history."