Deep structural properties yield better concepts than observable surface qualities.

Evidence

For example, we can ask what “copper” is. One property of copper is its reddish color. However, we would not consider a definition of copper based on its color very adequate; much better would be a conceptualization of copper based on its atomic structure. The atomic structure of copper is a better and more useful basis for thinking about copper than an approach based on qualities like its redness. One way to think of this is via the disease-symptom metaphor. — Gary Goertz, Social Science Concepts, 192

Categorization

• SEED: Article angle: ‘The Redness of Copper’ — why the best definitions of anything, from elements to institutions, target the generative structure and treat visible traits as symptoms.
• DEFINE: Introduces the disease-symptom metaphor: surface markers are effects of a deeper constitutive cause, and good conceptualization aims at the disease.