For the medieval theologian St. Thomas Aquinas (1225-1274), a beautiful thing had three primary characteristics (Summa Theologica, First Part, Question 39, Article 8):
1. Integritas (wholeness) –
It must not be deficient in what it needs to be most itself.
2. Consonantia (proportionality) and –
Its dimensions should suitably correspond to other physical objects as well as to a metaphysical ideal, an end.
3. Claritas (radiance) –
It should clearly radiate intelligibility, the logic of its inner being and impress this knowledge of itself on the mind of the perceiver.
Architectural historian and liturgical design consultant Dr. Denis McNamara, assistant director at the Liturgical Institute of the University of Saint Mary of the Lake/Mundelein Seminary (Illinois, US) explains:
Integritas, claritas, and consonantia prove critical in building a church, because as a theological and sacramental revelation of the new heaven and new earth, a beautiful church will provide a fullness of theological ideas but being complete not only in all of its functional parts, but also in its sacred imagery. Moreover, these parts will be proportional to their nature, showing not merely an earthly meeting hall, but an icon of a glorified reality, conventionally understood in architecture through sophistication of design, rich materials, and high levels of craft to be worthy of a church. This worthiness and glorification is made knowable to the mind of the viewer, for whom the church building impresses into his or her mind the signs and symbols of heavenly realities. This participation in the liturgy is the aim to be considered before all else specifically because by perceiving heavenly realities in earthly matter, we have the opportunity to become heavenly ourselves, and we are suited to live happily with God for eternity.
~ Denis Robert McNamara, Catholic Church Architecture and the Spirit of the Liturgy (2009)
Featured: St. Thomas Aquinas by Sandro Botticelli, 1481-82 (detail), The Granger Collection New York, Britannica
Below: Chartres Catheral by User “MMensler”, CC BY-SA 3.0, Wikimedia Commons