In this book Eli Hirsch identifies and explores a 'new' philosophical problem. Hirsch calls this new problem 'the division problem'. This is defined as the problem of explaining why our language divides up reality in one way rather than another, or what the rational basis is for our language to contain certain kinds of general words rather than others. Hirsch shows that a language can be constructed which describes reality in ways we would find absurdly irrational, for example by classifying normally disparate items under the same general term. Having demonstrated that this newly identified problem is in fact a serious one which cannot be easily solved or brushed aside, Hirsch offers his own suggestions for a possible solution.