Mere numerical dualism, not quantification, creates the tertius gaudens advantage.

Evidence

More generally, if a duty is turned over to two, the most important idea is that each of them now has to do less than the one did who formerly had been burdened with it alone: in comparison with this notion, the more exact definition of the quantum recedes, and can therefore easily be changed. In other words, the merely numerical fact of the party’s two-ness, instead of oneness, here engenders, so to speak, the situation of tertius gaudens. — Georg Simmel, The Sociology of Georg Simmel, 4534

Categorization

• DEFINE: Precisely delimits tertius gaudens — it arises from the fact of two-ness itself, not from any exact quantum.