Another expression for "eternally true" is often "bloody obvious" though. And even in cases where it isn't, the first source is not usually the one we go back t

Another expression for "eternally true" is often "bloody obvious" though. And even in cases where it isn't, the first source is not usually the one we go back to; it's certainly not true that we all keep reading Euclid's Elements to learn about the deep mysteries of maths. No, just being right is an insufficient explanation for why textbooks will obtain the mythical status of the works you reference.