An Epistemological Note on Chirality

The terms “chiral” and “achiral” are sharply defined when applied to geometric figures or models. The same terms are also commonly used to refer to the real systems to which these models have been adjoined, e.g., molecules, solvents, or reagents. Here, the terms are not sharply defined but depend upon conditions of measurement. The contrast between the geometric and operational usages is discussed in detail.