The square occupies a pivotal position in the depth-psychological corpus as a symbol of earthly manifestation, fourfold structure, and the tension between bounded form and infinite wholeness. Jung treats the square with exceptional seriousness throughout his writings: it appears in dream-series as a city square, a prison cell, a rotating room, a garden — always in dialectical relation to the circle. The central drama is the ‘squaring of the circle,’ that alchemical synonym for the magistery, in which angular imperfection is superseded by circular perfection, or alternatively, the circle is given concrete, terrestrial embodiment in four-sided form. Edinger extends this into developmental psychology, noting that the emergence of ‘squareness’ from the primal circle marks a differentiation of consciousness from unconscious wholeness. Black Elk’s lament — ‘there can be no power in a square’ — is cited to illuminate the cost of that differentiation. Plato’s Timaeus contributes the mathematical substrate: the square as the face of the cube assigned to earth, the most stable and immobile element. In astrological usage, the square aspect (90°) names a condition of dynamic tension between planetary principles. Across all registers — geometric, alchemical, astrological, cosmological, psychological — the square names bounded, differentiated, earthly reality straining toward reunion with the encompassing circle of the Self.