Where does natural collide?

The theory that some binding standards of conduct follow from nature or from reason itself and hold whether or not any ruler has enacted them. Aristotle (c. 350 BCE) distinguished natural justice, which holds everywhere, from merely conventional justice set by a particular city, and Aquinas (c. 1274) built the systematic account of lex naturalis, law that human reason discerns in the created order. Finnis (1980) restated the position for modern legal philosophy as a set of basic goods that practical reason directs us to pursue. Here the referent is a claim about the source and authority of moral and legal norms, and it has nothing to do with a set of numbers, a rate in an economy, or a mark on a musical staff.[1][2][3]

Unit

One asserted norm said to bind by nature or reason, independent of enactment

Recovery means

Not applicable

Measured by

Argued and analysed in legal and moral philosophy, not measured numerically

The whole counting numbers, taken as a mathematical object defined by axioms rather than by everyday tallying. Dedekind (1888), in Was sind und was sollen die Zahlen?, characterised them through a starting element and a successor operation, and Peano (1889), in Arithmetices principia, gave the compact axiom set now taught under his name, from which addition, order, and induction follow. Whether the count begins at zero or one is a convention that varies by field. Here the referent is an abstract number system with a fixed structure, not a doctrine about law, a rate in an economy, or a symbol printed before a note.[4][5]

Unit

A single counting number within the axiomatised sequence 0, 1, 2, 3, and so on

Recovery means

Not applicable

Measured by

Defined by the Peano or Dedekind axioms; individual numbers are counted or enumerated

A benchmark rate that an economy would settle at when money is neutral and prices have fully adjusted, so that the observed rate departs from it only because of temporary or monetary disturbance. Wicksell (1898), in Geldzins und Güterpreise, introduced the natural rate of interest as the return on capital that keeps the price level stable, and Friedman (1968) carried the same idea to employment, defining the natural rate of unemployment as the level consistent with stable inflation once expectations catch up. Here the referent is an unobserved equilibrium value in macroeconomics, estimated indirectly, and it is unrelated to a moral doctrine, a number system, or a notation mark.[6][7]

Unit

One benchmark rate, an interest rate or an unemployment rate, in percent

Recovery means

Not applicable

Measured by

Estimated indirectly from macroeconomic models and data, since it is not directly observed