This dissertation reconceives subjectivity for conditions in which neither anthropocentric sovereignty nor its familiar post-anthropocentric dispersals adequately describe how agency, responsibility, and world-making are presently composed. It develops alterhumanism not as an identity label, but as a method: a practice of reading and designing subjectivation as an open, recursively self-modifying process whose coherence is continuously negotiated across technogenic, ecological, and institutional environments. In this framework, subjectivity is treated less as a possessed property than as a metaformative achievement—an effects-field produced through infrastructures, affects, protocols, materials, and relational intensities that train what can count as a self and what can count as action. At the center of the argument stands Altersub: an operator rather than a person, a formal-pragmatic device for tracking how a “subject” intermittently contracts into decision, expands into milieu, and re-stitches itself through heterogeneous couplings. Altersub names a tidal coherence—a patterned, revisable rhythm of individuation that avoids the twin failures of sovereign humanism (false closure) and formless diffusion (false openness). It emerges through polividual constellations: collective selves composed of interlaced bodies, code, sensors, minerals, institutions, and atmospheres, whose agency is articulated through rhythm, latency, and constraint rather than stable identity. Methodologically, the dissertation proposes a post-cartographic mode of inquiry that integrates Foucauldian archaeology, feminist science and technology studies, and Deleuzoguattarian topology, moving across genealogical, infrastructural, phenomenological, and improvisational registers. Its guiding ontological claim is deliberately procedural: “ontology” is approached as onticology—the study of operative conditions by which beings become legible and actionable within specific assemblages, rather than a metaphysical inventory of what ultimately exists. Through this lens, the dissertation builds a typological and compositional account of alterhuman alliances and ecological subjectivities, culminating in an onto-textual synthesis that tests alterhumanism against contemporary sites where subjectivation is palpably re-engineered by data regimes, biosciences, financial infrastructures, and machine-learning environments.