Are there any text books that have original thoughts these days? I see all these footnotes, references, etc.......I get the feeling that, over time, the whole thing becomes like a game of "Telephone," where each person slightly changes the thoughts of their sources, until the most modern sources have totally garbled and unreliable information.

I work as a "text converter" (i.e. converting textbooks to electronic formats that people with certain disabilities can read/listen to), so I see quite a lot of textbooks........and who knows how many footnotes and references........