These three concretes have something important in common: (1) A baby born without a rational faculty (2) A dog with no sense of smell (3) A flat tire They are all broken units. “A unit,” according to Rand, “is an existent regarded as a separate member of a group of two or more similar members” (ITOE 6). This particular chair I’m sitting on, for example, is a unit of the concept chair. A broken unit, then, is a unit that lacks a characteristic shared by the other units of the concep