LCC has the property of being what Tarski calls a “language of finite order”. The idea of order is familiar. Variables for individuals (non-existent in LCC) are of order 1. Variables for classes of individuals (all the variables of LCC) are of order 2. Variables for classes of classes of individuals are of order 3, and so on. The order of a language of this series is the greatest positive integer n with variables of order n. (Thus, although LCC looks grammatically just like a first-order language, semantically it can be seen as a fragment of what under present conventions would be called a second-order language.)