Wholeness
Only a compound can be beautiful, never anything devoid of parts; and only a whole;
the several parts will have beauty, not in themselves,
but only as working together to give a comely total.
Yet beauty in an aggregate demands beauty in details:
it cannot be constructed out of ugliness; its law must run throughout.—Plotinus, First Ennead
The wholeness of a thing is related to its "big picture", overall arrangement, or gestalt. The term comes from ChristopherAlexander's NatureOfOrder. Wholeness is robust to certain types of changes in the thing, which we'll call WholenessPreserving or WholenessExtending. On the other hand, WholenessDestroying changes disrupt the existing wholeness and replace it with a new one (which usually has less Life than the old one, due to the destruction).
The drawings below, by ChristopherAlexander, show various transformations of an octagon. 8 people were asked to judge each transformation as "structure-preserving", "structure-destroying", or "don't know". The tallies of their responses appear below each image.
Wholeness is related to (but not fully explained by) Symmetry. In simple shapes at least, wholeness-preserving transformations tend to be those that maintain existing symmetries.
The wholeness of a person's face and voice is what allows us to recognize them. The four self-portraits of Matisse below are all different, yet capture the wholeness of his face.
Birders use wholeness to identify species: https://www.fieldmuseum.org/blog/jizz-andor-gestalt
The wholeness of a codebase is related to its purpose, architecture, and idiom. Imagine coming back to a codebase you haven't seen in 5 years, that has had dozens of people working on it during those years. It will probably be very different from what you remember, but the wholeness will likely be the same (unless there was a BigBangRewrite).
TODO: check out David Waltz 1972
Wholeness-destroying changes create Mess. Wholeness is destroyed, not by chaos, but by the imposition of conflicting orders.
Mess is only perceptible because it produces in our minds an imaginary order that is missing.