As an educator, I must agree that it really depends upon the class you're taking. For example, if you're studying something like Law, which is in a constant state of renewal and advancement, you kind of need the new textbook as the old one will be out of date almost immediately after you buy it. However, I have a book of contemporary criticisms of 'The Romantics' which is over a century old. This book still serves me well as literary criticisms are still valid, regardless of when they were made.

I imagine that it's important to buy up to date science textbooks to, lest you look like a fool when quoting studies that show women have smaller brains and how the "Red Man" is predisposed to fighting and firewater.

This isn't really true, most science textbooks just switch a few chapters around and change the numbers to the problems and that's about it.

I have very little knowledge when it comes to science, so I was assuming. My point was that it may be unfeasible to use a VERY old textbook for this subject, due to the advancements. I also assumed that NEW SCIENCE happens each year, but I'm obviously wrong. HAVE WE STAGNATED!?!