There is a huge amount of information that has been written down. Different authors have different explanations and takes on things, and will emphasize differen

There is a huge amount of information that has been written down. Different authors have different explanations and takes on things, and will emphasize different aspects of a topic in their presentation. Look at the recommended texts section: http://www.staff.science.uu.nl/~gadda001/goodtheorist/texts&resources.html http://www.staff.science.uu.nl/~gadda001/goodtheorist/texts&... He doesn't just cite one text on Classical Mechanics, he cites 5, and in his section on internet resources http://www.staff.science.uu.nl/~gadda001/goodtheorist/classmech.html http://www.staff.science.uu.nl/~gadda001/goodtheorist/classm... He cites 3 more courses. There is a lot of depth in any of these topics, and any given presentation will be a single path, of many, through the topic. Different perspectives are valuable, as they also help clarify the core of the topic, and allow you to find your own perspective. We are fortunate that there are people who have invested the effort to put some of these resources online, but not everything is currently on the internet. One day perhaps. Also, some of the internet resources that he links to are now gone, and may or may not have been archived. Textbooks that are cited are almost certainly guaranteed to be available through some library. Given that he's also advocating that serious students attend University, proposing books to read that students can access through ILL seems reasonable.