Formulating a theory of signification doesn't seem to be one of philosophy's current preoccupations. Whether suffering from a malaise after the so-called linguistic turn, or placing its hopes on the algorithms of the future to figure out language's "emergent properties," the thinking of the sign seems to have lost most of its vigor. Nevertheless, a theory of signification remains indispensable for contemporary efforts that depend on a certain proof of a philosophical absolute, the great outdoors of speculation. One could say that a consistent theory of signification is the sine qua non for any access to such an absolute, simply because it would always already be at the same time an absolute limit to language. We may refer to such a theory as a speculative theory of signification,1 whose core, I would argue, would consist in a clear distinction between the mathematical and the non-mathematical (philosophical, linguistic, poetic) sign.