Εις, δύο τρεις: ο δε δη τέταρτος πού; [One, two, three: but where is the fourth one?]

Poets describe beautiful women with three colours, plus a fourth one. This pattern, between a triad and a tetrad, took shape in the Hellenistic period, spread (with some occasional deviations) during the Middle Ages, and collapsed with Don Giovanni and the emergence of modern science in the 17th-18th centuries, when the seat of the soul shifted from the heart to the brain.

The subject is discussed along two main lines. The first is about the interdisciplinary nature of the topos system. The topos is shared, since it is the point of convergence of ways of thinking that tend to be separated in today’s culture, therefore hard to grasp by the expert’s eye. The second relates to the archetypical character of the system, i.e. essentially the relations which the topos of beauty maintains with the doctrine of the Trinity. Ultimately, any reflection about beauty can only be theological.