It was none less than Thomas Hobbes who wrote (if only in passing) of an “Inconstancy from the Number,” thereby hitting upon a central problem of democracy, as well as its perpetual need for legitimizing justification (Schmidt 2010, 52):

While a nondemocratic system tries to guarantee permanence and stability to its subjects while demanding the same from them, but regardless of their will (and thus must always fail in the long run because they are ultimately based on force, not legitimation, a situation that will not be examined more closely here), democracy promises to guarantee their legal rights, and not despite its citizens, but explicitly in accordance with their will, while thereby also assuming the perpetual risk of changes resulting from inconstancy (cf. Salzborn 2012a).

This “Inconstancy from the Number” is an unavoidable challenge for every theory of democracy. This is because democracy is a political system promising something it cannot guarantee in the long run, and yet must promise in order to ensure its long-term existence (on this see also Böckenförde 1976), namely the stability of its freedoms-based system, one that exists precisely because of this “Inconstancy from the Number.” This is a system that can legitimize its continued existence only through its instability, one that (in contrast to all other political systems) guarantees its citizens the option of having divergent opinions, a system that regulates conflicts while constantly producing more.

The inconstancy of the masses is a problem frequently discussed by historical thinkers. It is difficult to resolve because the issue is not just a mathematical one, so it cannot be settled by simply adding up the numbers. For example, James Madison wrote extensively on the proper ratio between representatives and the represented (Hamilton et al. [1787] 2003, Federalist Papers nos.10 and 55), which was to be neither too small nor too large: