When Gilbert Ryle introduced the phrase category mistake he gave a number of examples. The first example is of a visitor to Oxford. The visitor, upon viewing the colleges and library, reportedly inquired "But where is the University?". The visitor's mistake, explains Ryle, is presuming that a University is part of the category "units of physical infrastructure" or some such thing, rather than the category "institution" , say, which are far more abstract and complex conglomerations of buildings, people, procedures, and so on.