A friend of mine -- a literature major -- in college asked me why we Engineers didn't want to "acknowledge the origins" of the work we studied. He said that he thought he would much rather read the original works of Newton or Leibniz to understand calculus as opposed to the "dry" textbook I was reading.

I think the issue is that the original work is not the clearest explanation. You have to invent new vocabulary for the context, new notation and explain it at the same time. The textbook is a much more efficient delivery mechanism for understanding and it is honed over time.

The original texts are often inscrutable, and they have a different rhythm to them. It reminds me of watching the great movies. Occasionally there will be one that has not aged -- like the Godfather. More often, I can't believe people enjoyed this (examples withheld).