 This is precisely the type of thinking that Windelband will later reject as “psychologistic”, “historicist”, and “relativist” (1883: 116–117, 132). It is not clear what led Windelband to this change of view, but a deeper engagement with the Critique of Pure Reason and with the Kant scholarship of his time, in particular with works by Kuno Fischer (1860), Herman Cohen (1871), and Friedrich Paulsen (1875), seem to have factored in. The clear contours of Windelband’s anti-psychologistic interpretation of Kant emerge for the first time in his 1877 paper “Über die verschiedenen Phasen der Kantischen Lehre vom Ding-an-sich” [“On the different stages of the Kantian doctrine of the thing-in-itself”]. In this essay, Windelband argues against the idea, held by prominent figures of the “back-to-Kant” movement like Friedrich Albert Lange (1828–1875) and Hermann von Helmholtz (1821–1894), that knowledge emerges from an interaction between subject and object. According to their view, the object affects the subject’s mind, while the subject provides the a priori cognitive structures that organize representations. These a priori structures are innate as they consist in the psychophysical constitution of the human sensory apparatus and mind. Cohen’s critique of this (mis)interpretation focuses on the concept of the a priori and the question of objectivity (Cohen 1871). Windelband, in contrast, takes the problem of the thing-in-itself and the concept of truth as his starting points. His critique of the subject-object-interaction model leads him to an immanent conception of truth, according to which truth consists in the normative rules according to which our judgments ought to be formed. The immanent concept of truth thus shifts the focus of philosophical analysis on the universal and necessary “rules” that ground our judgments.