Strict incommensurability makes defining any complex concept impossible.

Evidence

In a more philosophical vein, scholars argue that dimensions are incommensurate. For example, in Disadvantage, Wolff and De-Shalit argue vigorously against reducing all the elements of lives to a single numerical scale. They argue that aggregation across the diverse elements of lives is bound to miss things of vital importance. For example, Sen describes “non-commensurability” as “a much-used philosophical concept that seems to arouse anxiety and panic” (2009, 240). In philosophy, incommensurability is used as an argument against aggregation at all (e.g., Chang 1998). In practice a complex concept or definition involves putting together different components. So at some important semantic level one cannot even construct a definition if one is strict about the noncommensurability of defining features. — Gary Goertz, Social Science Concepts and Measurement, 114

Categorization

• XREF: Speaks directly to capability-approach debates (Sen, Nussbaum) and to Wolff and De-Shalit’s Disadvantage — an argument that philosophy’s anti-aggregation stance is self-undermining.