 Throughout his career, Lacan exhibited a serious interest in various branches of mathematical and formal disciplines. This goes as far back as the 1940s, with the recourse to game theory in “Logical Time and the Assertion of Anticipated Certainty.” The turn to structuralism at the end of the 1940s and beginning of the 1950s reinforced these formalistic tendencies, with Lacan, in the 1950s, already drawing upon not only game theory, Lévi-Straussian anthropology, and Jakobsonian phonology, but also the history of mathematics and topology. Throughout the 1950s and 1960s, more and more diagrams, graphs, and symbolizations appeared peppered throughout Lacan’s lectures and writings, testifying to a steadily intensifying trend toward formalization. By the late 1960s and, especially, the 1970s, discussions of logic, topology, and knot theory were prominent (sometimes even dominant) features of Lacanian discourse. In relation to Lacan, the 1970s could be characterized as the decade of the “matheme,” Lacan’s neologism for a unit of formalization (qua a mathematical-style symbolization) distilling and fixing the core significance of a specific Lacanian analytic concept-term. Lacan hoped thereby to avoid being misinterpreted in the ways that Freud’s deceptively accessible employments of natural language allegedly allowed most non-Lacanian post-Freudians to perpetrate. Additionally, topology, as a science of surfaces, provided Lacan with resources for his regular assaults on the crude, popular images of psychoanalysis as a “depth psychology,” with these images relying upon the simplistic two- and three-dimensional Euclidean spaces of spontaneous picture thinking. Topological figures and constructions undermining the intuitions of this picture thinking assisted Lacan in recasting the unconscious as an ensemble of contortions, curvings, folding, inflections, twists, and turns immanent and internal to a single plane of minded subjectivity accessible to rigorous, rational (psycho)analysis.