The term ‘measurement’ occupies a distinctly contested position in the depth-psychology corpus, cutting across epistemological, clinical, and philosophical registers. Three broad positions can be identified. First, within early experimental psychology, Jung’s galvanometric and reaction-time studies treat measurement as a legitimate, if necessarily approximate, instrument for detecting the presence and intensity of emotionally charged complexes — a methodological faith in quantification tempered by awareness of its inherent incompleteness. Second, Jung’s theoretical writings on psychic energy establish a principled tension: exact measurement of psychic quantities is structurally unavailable to psychology, which must substitute the valuation function of feeling for the concrete measurement available to physics. This epistemological gap is not merely practical but constitutive. Third, from a philosophical direction, Nussbaum’s reading of Plato’s Protagoras and Seaford’s analysis of Greek monetary thought expose measurement as a deeply normative project — the ancient ‘techne of measurement’ proposed by Socrates represents nothing less than an ethical science of commensurability, promising salvation from the tyranny of competing appearances. Pauli’s quantum-mechanical reflections add a further layer: the act of measurement disturbs the system measured, rendering full determinacy impossible. Across these voices, measurement appears simultaneously as psychology’s aspiration, its limitation, and, in the Platonic-monetary tradition, as a cultural fantasy of mastery over the irreducible plurality of value.