Emil Lask’s transcendental philosophy is one of the first points of view that tries to evade the monistic inclinations of the transcendental philosophy (Kant, Fichte). Lask sets as presupposition of the knowledge the “categorial differentiation”, a structure that is immanent to the relations between subject and object, knowledge and reality, “validity” and “existence”. This paper analyses this kind of “difference” – a “deviation (Abweichung)” or a “shift (Verschiebung)” conceived beyond the contrast, in a non-oppositional way – and shows that Lask is moving in a direction that anticipates “solutions” which are peculiar to the contemporary philosophy of difference (Derrida, Deleuze).