German idealism turned classical logic into a speculative method. Logicism tried to ground speculation in mathematical logic. Structuralism speculated with mathematics. First, with combinatorics and finite mathematics. Later, with analysis and topology. Finally, with set theory. The ultimate question is, however, the expressivity that formal languages grant to philosophical concepts. It is vain to claim that “mathematics” or “logic” is the ultimate structure of reality or ontology. There isn’t a single philosophical issue explicitly formulated in formal languages. There is always a philosophical decision in choosing a formal framework and in assigning philosophical to mathematical concepts. To jump from mathematics to philosophy is an act of self-deceit.