This chapter investigates the power and influence of Menschenbilder—conceptions of what it means to be human—on individuals and societies. Building on Nietzsche’s insight that these conceptions are not merely reflective but constitutive, it argues that Menschenbilder shape perception, emotion, judgment, and behaviour; structure institutions; and ultimately mould the very constitution of human beings. They operate through three interrelated domains. (1) Intentionality: Menschenbilder guide how individuals perceive, feel, and act, determining who is recognised as human and how humans are interpreted. (2) Institutions: legal, moral, and educational systems embody and legitimise a society’s prevailing Menschenbild, as shifts in these images correspond to epochal transformations in cultural and institutional forms. (3) Constitution of individuals: through processes of socialisation, imitation, and self-regulation, people internalise their society’s Menschenbild, which becomes part of their identity, influencing personality, body, and self-understanding. In sum, Menschenbilder not only describe humanity but also create it—they are formative, normative, and performative forces within culture.