If we consider a textbook, then obviously the factual contents are usually way more than what could be summarized in one sentence. “Twenty or so mathematical concepts, plus 1-5 ways to manipulate each concept and link it with the others”, except that’s not the factual content, it’s merely a description of the factual content.
But also with a textbook, ideally, as you the reader go through it, you work with it: in a math textbook you work through examples or try to prove things yourself, in a science textbook you ask questions like “Is that really true?” or “How did they know that?” or “Does that mean someone could make technology exploit that effect? Are they already doing this?” or other stuff. This will (a) solidify the knowledge in your mind and (b) give you practice at thinking / investigating the subject matter.
Even if some nonfictional book is not a textbook and consists entirely of a thesis sentence and a collection of evidence and arguments to prove the thesis, you the reader can work with it: take each thing and ask how it might be wrong, if the evidence admits different interpretations, if there’s a hole in the logic. You can come away from it with (a) good practice at interrogating claims, (b) either familiarity with a good example of how to do investigation of that subject, or knowledge that the author was deficient and yet managed to get their book published; and (c) either a solid understanding of the important things connected to the central claim, or a list of holes the author didn’t fill and that you might follow up on.
Things that come to mind:
If we consider a textbook, then obviously the factual contents are usually way more than what could be summarized in one sentence. “Twenty or so mathematical concepts, plus 1-5 ways to manipulate each concept and link it with the others”, except that’s not the factual content, it’s merely a description of the factual content.
But also with a textbook, ideally, as you the reader go through it, you work with it: in a math textbook you work through examples or try to prove things yourself, in a science textbook you ask questions like “Is that really true?” or “How did they know that?” or “Does that mean someone could make technology exploit that effect? Are they already doing this?” or other stuff. This will (a) solidify the knowledge in your mind and (b) give you practice at thinking / investigating the subject matter.
Even if some nonfictional book is not a textbook and consists entirely of a thesis sentence and a collection of evidence and arguments to prove the thesis, you the reader can work with it: take each thing and ask how it might be wrong, if the evidence admits different interpretations, if there’s a hole in the logic. You can come away from it with (a) good practice at interrogating claims, (b) either familiarity with a good example of how to do investigation of that subject, or knowledge that the author was deficient and yet managed to get their book published; and (c) either a solid understanding of the important things connected to the central claim, or a list of holes the author didn’t fill and that you might follow up on.