When Ives Tanguy painted his mysterious imaginary landscapes he realized in artistic form a tableau that shows never-seen, quasi-real imaginary things within a quasi-real imaginary space. The imagination that presents such things is totally free—accompanied by “the feeling of an absolute freedom,” as Tanguy said—, whereas the product is a world that not only looks as if it were real but appears as a coherence of facts put together with unshakeable necessity. The imagination is free because it undertakes the ultimate challenge: it creates imaginary products in a way that they give the impression of being real. This imagination realizes itself like the dreaming I but in a state of not-bounding-itself (better to say: as an imaginative force that both reveals and confirms the self-bounding imagination); and it realizes a kind of world experiencing with correlative objects that seem to be real (comparably to a trompe l’oeil) although they can never be found within the real world (contrary to a trompe l’oeil).

In this paper, I will investigate the temporal structure of photographic images. According to a common understanding, photographic images open up a direct access to what has been recorded in the past. In contrast to this view, I will show that photographs have to be conceived in terms of a higher temporal complexity. Referring to Derrida’s reflections upon trace, representation, and the temporal mode of the futur antérieur as well as his involvement in photography, I will understand the temporality of photographic images not as unidirectional relation of presence and past, but rather as an ongoing process of temporalization.

Georg Cantor, the originator of set theory, distinguishes between two kinds of actual infinity: he separates the transfinite from the absolutely infinite. Whereas the transfinite is the proper object of set theory, the absolutely infinite remains inaccessible to mathematical inquiry. In Cantor’s writings, the absolutely infinite seems to have both a positive and a negative aspect. It is shown in this paper how Cantor’s remarks on his forerunners in the history of philosophy—and especially on Nicholas of Cusa—help us to understand the inseparability of these two aspects.