Within the depth-psychology corpus, ‘Proportion’ carries a freight that far exceeds its arithmetical meaning. The term operates simultaneously as a cosmological principle, a psychological norm, and an aesthetic criterion. Its most architecturally developed treatment appears in the Platonic tradition — above all in the Timaeus — where geometrical proportion (the continued mean) functions as the very bond of cosmic unity: the ratio that integrates the four elements and structures the World-Soul itself. Plato’s insistence that ‘of all bonds the best is that which makes itself and the terms it connects a unity in the fullest sense’ establishes proportion as an ontological rather than merely quantitative concept. The depth-psychological tradition inherits this lineage: proportion signifies right relationship between psychic opposites, the balance of soul and body, of passion and reason, of part and whole. Edinger situates quantitative consciousness — measurement and geometrical imagery — within the alchemical operation of separatio, suggesting that ‘proportioning’ the psyche belongs to a discriminative, differentiating movement. Plato’s Laws and Timaeus further ground proportion in the equation of the symmetrical with the beautiful and the good, making disproportionality a mark of pathology. Across authors, the tension is between proportion as rational-mathematical constraint and proportion as an emergent, living harmony that exceeds calculation.
of all bonds the best is that which makes itself and the terms it connects a unity in the fullest sense; and it is of the nature of a continued geometrical proportion to effect this most perfectly.
This passage establishes geometrical proportion as the supreme ontological bond, the principle by which disparate elements are unified into a single whole — the cosmological ground of the concept.
, Plato’s cosmology the Timaeus of Plato, 1997thesis
The good is the beautiful, and the beautiful is the symmetrical, and there is no greater or fairer symmetry than that of body and soul, as the contrary is the greatest of deformities.
Plato identifies proportion (symmetry) between body and soul as the supreme form of beauty and goodness, making disproportionality a form of psychosomatic pathology.
, Timaeus, -360thesis
There is one protection against both kinds of disproportion:—that we should not move the body without the soul or the soul without the body, and thus they will be on their guard against each other, and be healthy and well balanced.
Plato prescribes the mutual cultivation of body and soul as the remedy for disproportion, framing psychological health as a dynamic equilibrium between opposing principles.
, Timaeus, -360thesis
from the proportion with equal terms arises the double proportion, and from that the triple, and so on
This passage traces the generative cascade of proportional series by which the World-Soul’s numerical structure is derived, showing proportion as the generative grammar of cosmic order.
, Plato’s cosmology the Timaeus of Plato, 1997supporting
fill up both the double and the triple intervals, cutting off yet more parts from the original mixture and placing them between the terms, so that within each interval there were two means
The harmonic and arithmetic means inserted between the World-Soul’s terms exemplify how proportion structures musical and cosmic intervals through precise mediation.
, Plato’s cosmology the Timaeus of Plato, 1997supporting
all things which do not admit of more or less, but admit their opposites, that is to say, first of all, equality, and the equal, or again, the double, or any other ratio of number and measure
Plato classifies fixed ratio and numerical measure — the essence of proportion — as belonging to the class of the Limit, contrasted with the unlimited flux of the ‘more and less.’
, Philebus, -360supporting
when the motions of the antecedent swifter sounds begin to pause and the two are equalized, the slower sounds overtake the swifter… thus producing a single mixed expression out of high and low, whence arises a pleasure
Musical harmony is presented as the acoustic realisation of proportion: the equalization of unequal motions produces pleasure and constitutes ‘an imitation of divine harmony in mortal motions.’
, Timaeus, -360supporting
Measurement, numbering, weighing, and quantitative consciousness in general belong to the operation of separatio. So, likewise, do applied arithmetic, the geometrical imagery of lines, planes, and solids
Edinger situates quantitative and geometrical consciousness — the operations through which proportion is established — within the alchemical process of separatio, linking proportion-making to psychic differentiation.
, Anatomy of the Psyche: Alchemical Symbolism in Psychotherapy, 1985supporting
between two square numbers there is one mean proportional number and between two cube numbers there are two mean proportional numbers
The mathematical commentary clarifies the Euclidean theorems underpinning Plato’s cosmological proportions, distinguishing the single and double means required to bond planes and solids respectively.
, Plato’s cosmology the Timaeus of Plato, 1997supporting
quaternarii proportio simpla et prima
Pauli’s Latin source identifies the quaternary’s ‘simple and primary proportion’ as the arithmetical basis of its theological and natural eminence, linking proportion to the symbolism of the number four.
, Writings on Physics and Philosophy, 1994supporting
having four terms and three intervals of numbers which are related to one another in certain proportions; these he converts into figures, and finds in them when they have been raised to the third power certain elements of number
The Republic’s ‘nuptial number’ passage deploys proportion as the governing principle of generational cycles, extending the cosmological function of proportion to political and biological time.
supporting
the unit had been held by the Pythagoreans to contain within itself both the ‘elements’ of number, the even (or ‘unlimited’) and the odd (‘limited’ or ‘limit’)
This Pythagorean aside contextualises the numerical series from which proportional intervals are derived, grounding the theory of proportion in the metaphysics of limit and the unlimited.
, Plato’s cosmology the Timaeus of Plato, 1997aside
Arithmetica etiam huius numeri eminentiam prae aliis numeris arguit; quippe qua scientia tam duplex ejus proportio optime explicatur
The text argues that arithmetic demonstrates the pre-eminence of the quaternary through its double proportion, associating proportional structure with the order of nature and divinity.
, Writings on Physics and Philosophy, 1994aside