What did Fichte mean when he said that the Ego posits itself?

In the philosophy of Johann Gottlieb Fichte, the statement that the Ego posits itself is a foundational principle of his system, intended to establish the subject as the absolute, unconditioned ground of all reality and experience.12

When Fichte says the Ego posits itself, he means that the Ego’s essence consists entirely in the act of self-assertion; it is not a pre-existing thing that acts, but rather an act that brings itself into existence. As Fichte articulated, "As it posits itself, so it is; and as it is, so it posits itself". By defining the Ego as an "absolute subject" that is free from the limitations of the external world, Fichte sought to resolve the tension between subject and object by making the moral requirements of the Ego the basis for all judgment on reality.13

This concept is closely linked to his second major proposition, that the "Ego posits the non-Ego," which explains how the subject creates the external world or objects of knowledge as a contrast to itself. Through this, Fichte aimed to demonstrate that practical, moral reason is the absolute root of all knowledge.243