I have been strongly recommended to read the book Naive Lie Theory. In the introduction one can read: "This naive approach to Lie theory is originally due to von Neumann, and it is now possible to streamline it by using standard results of undergraduate mathematics. To compensate for the limitations of the naive approach, end of chapter discussions introduce important results beyond those proved in the book, as part of an informal sketch of Lie theory and its history".

I would like to ask:

• first of all, what is Lie theory and is there some agreement that it should be a fundamental part of undergraduate education?

• could you elaborate a little on the book mentioned above? Is the naive approach somewhat too naive? Should I prefer other references?