Mechanistic physics occupies a pivotal and contested position throughout the depth-psychology corpus, functioning less as a neutral scientific descriptor than as a cultural and epistemological symbol whose adequacy is perpetually under interrogation. The corpus documents a decisive historical arc: from Newton’s reduction of nature to passive matter governed by calculable forces, through the nineteenth-century materialist hegemony that shaped Freud’s causal-mechanistic psychology, to the quantum revolution that shattered classical assumptions and opened new conceptual space for mind, meaning, and synchronicity. Jung and his immediate circle — above all in the collaboration with Wolfgang Pauli — constitute one major axis of engagement, treating mechanistic causality as a necessary but radically insufficient explanatory framework, one that must be supplemented by finalism, acausality, and the psychoid hypothesis. McGilchrist represents the other dominant axis, arguing systematically that the machine model — with its commitment to linear causality, static parts, context-independence, and upward reduction — is precisely the cognitive pathology of the left hemisphere writ large onto science. Von Franz, Rudhyar, Tarnas, and Conforti each contribute subsidiary but coherent positions: the mechanistic worldview is consistently identified as the receding ‘old king’ whose abdication is required before a genuinely participatory or archetypal understanding of nature becomes possible. The central tension running through all positions is whether quantum and process physics have, in principle, already dissolved mechanistic physics from within — or whether the life sciences and psychology still labor under its shadow.