In what follows I will deal with a specific function assigned to the Self (Ich) in the first paragraph of Fichte's Foundation of the Entire Doctrine of Knowledge. I will propose that this function can be characterized as an expressive one that refers to the self-undetermined position of the Self. Firstly, I will argue that this undeterminacy is necessary for the development of Fichte's philosophical project. Then I will suggest that this expressive function shows the philosophically radical nature of subjectivity. In doing so I attempt at making clear the importance of the self-expression of the Self in the development of Fichte's theory of subjectivity.