5. Fifth Lecture. Anstoss and the Irreducible Remainder

In this lecture, we revisit the profound relationship between infinity and finitude within Fichte’s philosophy, and I aim to demonstrate why he should not be regarded as a solipsistic thinker. By introducing the Anstoss as a contentless yet necessary "check" to the Ego’s activity, Fichte moves beyond pure determinism. This concept parallels later ideas, such as Žižek’s indivisible remainder, Lacan’s objet petit a, and Schelling’s irreducible remainder, all of which share an emphasis on a primordial limit or opposition as essential to freedom. In my view, Fichte’s Anstoss establishes the conditions necessary for freedom and self-determination, as free will presupposes the existence of the Absolute.


When we examined Fichte's first principle as the initial positing of the "I," we also observed that the "I" has a yearning to expand infinitely. This can be seen as a primordial inherent drive, similar to Freud's concept of the id. However, Fichte also introduces a counteraction to this expansion, describing it as a "check" ("Anstoss") that arises simultaneously with the active "Ego" and "Non-Ego," limiting the infinite expansion of the "Ego."

Fichte states:

"The check not posited by the positing Ego occurs only in so far as the Ego is active, and is therefore only a check in so far as the Ego is active; the activity of the Ego is the condition of the check."

Visualizing this concept, we can imagine the "I" (or "Ego") as a finite sphere within Absolute infinity. Within this framework, the "I" ("Ego") and "Not-I" ("Non-Ego") emerge as a result of the initial positing. The "Not-I" ("Non-Ego") can be conceptualized as another sphere situated within the boundaries of the "I" ("Ego"). Fichte elaborates: "The Ego is, therefore, limited, because a Non-Ego is posited through it."

The sizes of these spheres are interdependent: as the "Ego" expands, the surface area of the "Non-Ego" decreases, and vice versa. Simplified, one could conclude that within the Absolute Ego—a concept we cannot directly experience—there exists the interplay of the "Ego" (which we can experience) and the "Non-Ego" (everything outside of it).

Fichte’s treatment of this relationship is nuanced. Between the "Ego" and the "Non-Ego" lies a "hidden substance," something indivisible that mediates between these two opposites. This is the "check" ("Anstoss").

Fichte explains the relationship between this "check" and the "Ego" as follows:

"No activity of the Ego, no check. On the other hand, the self-determining of the Ego will be conditioned by the check. No check, no self-determination of the Ego."

He also connects the "check" to the Absolute Ego, stating:

"That is, the Absolute Ego is to be the cause of the mysterious thing in itself, the hidden substance, the check; all the rest follows necessarily in the manner shown."

So who or what is this invisible (and indivisible) "referee"? What is this contentless "check" or "Anstoss"? Fichte, as a staunch idealist, fiercely defended his system against accusations of dogmatism and materialism. Thus, he could not equate the "check" with Kant's "thing in itself," something external to the system. Such an interpretation would introduce an independent cause of qualitative difference and risk opening the door to materialist interpretations.

Paradoxically, however, the "check" achieves a similar effect by generating internal opposition, creating a difference within the system itself. Analogous to Schelling’s initial contradiction within the Absolute (explored earlier through the "Weltformel") that gives rise to opposing forces from the same substance, the "check" resembles an "irreducible remainder" ("B" in the Weltformel) closer to "nothingness" than to Kant’s noumena.

Fichte notes that the Ego "tends to fill up the infinite" through its outward-reaching activity. This tendency transforms into a drive. Regarding the activity of the finite Ego, Fichte emphasizes that the Ego is "being required by its very nature to determine itself."

Thus, the question arises: What exactly determines the Ego?

Fichte describes the mechanics: "The check ['Anstoss'] /.../ occurs only in so far as the Ego is active." Thus, the Ego's "outwardly proceeding activity," as its inherent property, causes the "check" ("Anstoss") to appear, while the "check" enables the self-determination of the Ego. Fichte succinctly states: "No check, no self-determination of the Ego."

However, the "check" ("Anstoss"), which facilitates the Ego's self-determination, is, as Fichte emphasizes, "not posited by either of them ['opposite parts within the Ego'], but by an independent positing." When he declares "no infinite, no limitation, and vice versa," he implies that the limiter of the finite Ego cannot originate "out of the Ego" and negate everything beyond its bounds. He further clarifies: "If the activity of the Ego were thrown back by this check, that activity which lies beyond the line of the check would be completely annihilated and canceled; and the Ego in so far would not posit at all."

Thus, the "limiter" ("check," "Anstoss") must possess a transcendental origin—something more primordial. Here, we observe a resemblance to Schelling's Weltformel "B" as the indivisible remainder: an Absolute "error" within the structure that enables its continued function. Fichte expresses this idea explicitly: "['Ego'] determines itself by the predicate of the infinite." The finite Ego can only achieve self-determination by simultaneously positing itself as non-positing — placing within its sphere the undetermined and unlimited—and thereby asserting its infinite nature.

This interpretation allows Fichte's statement to gain further depth: "The Ego is finite, because by positing the Non-Ego it limits itself; it is also infinite, because it may posit the Non-Ego infinitely. It is finite in its infinity; infinite in its finity."

From this, we can conclude that the "limiter" of the Ego (the "check" or "Anstoss") is precisely what fuels its drive. Without the limiter, the Ego’s infinite outreach would not manifest as a drive; without the drive, there would be no active self-limiting or self-determination. Resistance is essential for the Ego's outreach to become a meaningful drive.

This notion also permits a deeper understanding of Fichte's first principle, "I = I." Here, the first "I" may represent the infinite Ego, while the second "I" refers to the finite Ego. When countering claims of Fichte's supposed solipsism, this interpretation of "I = I"—combined with the primordial "check" ("Anstoss") that enables it—serves as a compelling argument.

Žižek also perceives the "Anstoss" as something primordial: "Anstoss is the transcendental a priori of positing, that which incites the I to endless positing, the only non-posited element." In Less than Nothing, he compares it to Lacan's objet petit a: "Anstoss is formally homologous to the Lacanian objet petit a," much as he associates it with the "irreducible remainder" of Schelling’s Weltformel in The Indivisible Remainder.

In simplest terms, Fichte can be understood as not entirely solipsistic. In his Science of Knowledge, he introduces the concept of the Ego being limited by a contentless "check" (Anstoss). This check can be interpreted as a marker of absolute infinity within finitude, akin to Schelling’s Weltformel’s irreducible remainder, Žižek’s indivisible remainder, or Lacan’s objet petit a.