This chapter explores the historical continuity linking humanism, transhumanism, and posthumanism through the evolving concept of the human body. Beginning with Renaissance automata and early modern mechanistic physiology, it shows how attempts to model, enhance, or replace bodily functions laid the groundwork for contemporary visions of cyborgs and mutants. Descartes’ dualism emerges as a pivotal turning point, enabling both the mechanization of the body and the abstraction of mind that posthumanism radicalizes. The chapter argues that aspirations to transcend human limits—whether through prostheses, reanimation, cognitive amplification, or bodily substitution—are not modern inventions but deep-rooted humanist ambitions reframed by technological progress. By tracing these ideas across medicine, philosophy, and the arts, the chapter reveals how eccentric bodies migrated from metaphor and mechanism to speculative futures. Ultimately, it situates trans- and posthumanist thought as extensions of a long-standing inquiry into human nature, its capacities, and its possible transformations.