Serge Lang and categories I was told that (Serge) Lang has never fallen in love with categories, to use a polite euphemism. Other people claim that, in some occasion, he has even declared his lack of interest in the subject in a somewhat harsh tone. However, I couldn't find anything (explicit) in his work in favor of these claims. Is there any document (a letter, a paper, a book, ...) where one can clearly read about his point of view on category theory? Is there any anecdote or personal episode that you could eventually tell in respect to this?
 A: From p.105 of the first edition of Lang's Algebra, under the heading EXERCISES:

Take any book on homological algebra, and prove all the theorems without looking at the proofs in that book.
Homological alebgra was invented by Eilenberg-MacLane. General category theory (i.e. the theory of arrow-theoretic results) is generally known as abstract nonsense (the terminology is due to Steenrod).

In response to amWhy's comment, I looked at the Revised 3rd edition of the book, where the section on Homological Algebra contains a much kinder but still recognizable version of the above:

In the forties and fifties (mostly in the works of Cartan, Eilenberg, MacLane, and Steenrod, see [CaE 57]), it was realized that there was a systematic way of developing certain relationships of linear algebra, depending only on fairly general constructions which were mostly arrow-theoretic, and were affectionately called abstract nonsense by Steenrod.

According to this MO answer, the quote is unchanged between the first and second editions.
