This essay attempts to outline Jacques Derrida’s envisaged rewriting of transcendental aesthetics, hinted at in De la grammatologie. Focusing mainly on the texts published during the 1960’s (especially La voix et le phénomène) and the early 1970’s, I try to situate Derrida’s thought within the horizon of transcendental philosophy. Special attention is devoted to Immanuel Kant and Edmund Husserl given the importance that Derrida ascribes to them. My intention is to capture Derrida’s position towards these previous attempts of formulating a transcendental aesthetics. In Derrida’s view – the way I interpret it – transcendental aesthetics is a set of issues concerning (i) the philosophy of time and space and the constitution of time and space, (ii) a theory concerning the constitution of conditions (iii) a theory concerning the lowest level of cognition. I will try to support the claim that Derrida’s famous notion, la différance, entails a recasting of previous notions of transcendental aesthetics. Derrida is well known for his claim that experience is not direct; it must be given through re-presentations, which synthesize sense (ideal objects) and the sensed. Ideal objects are themselves dependent on language and hence experience cannot be brought about without the mediation of language. In this essay the claim that neither space nor time would be without the sign is substantiated. With this in mind I attempt to show that Derrida’s rewriting of transcendental aesthetics amounts to promoting the concept of spacing, which represents the-becoming-spaceof-time and the-becoming-time-of-space. Without the deferring and differing involved in the movement of la différance and the writing of the unconscious there would be neither time nor space. One of the most important outcomes of this essay is the presentation of the interplay between activity and passivity involved in the constitution of ideality performed by unconscious writing.