We realise the profundity of this insight is pretty tough to beat. But fortunately, the greatest philosopher of the past 2000 years is up to the challenge. From her "Introduction To Objectivist Epistemology" Chapter 2, Concept Formation:
"I shall identify as ‘length’ that attribute of any existent possessing it which can be quantitatively related to a unit of length, without specifying the quantity."Yes folks, according Ayn Rand 'length' is that 'attribute' which can be 'quantitively related' a 'unit of'....wait for it...'length!'
Phew! It's just as well for Western Civilization that Rand was around to straighten out such challenging philosophical issues.