What’s an older nonfiction title that’s relevant and blew your mind?

Question

One of mine I taught a university course with, the psychology of perception. Not an easy read, the students hated me, but some understood what Gibson was on about. Deeply radical thought. Gibson once said psychology was a second rate discipline because it didn&rsquo;t stand in awe of its subject matter. So trueBook: Edward S. Reed James J. Gibson and the Psychology of Perception (Yale)

LukeBMM · Accepted Answer

Based in part off Gibson's work, there's also The Design of Everyday Things by Donald Norman. First published as Psychology of Everyday Things in '88, it's arguable whether it counts as "older" but seems pretty timeless conceptually, even if the specific examples may become dated.
https://en.wikipedia.org/wiki/The_Design_of_Everyday_Things
Edit: Oh, yeah. How about Tufte ('83 for Visual Display of Quantitative Information) and Albers (Interaction of Color in '63). I should think first, then post.

regera · Answer

Pluto's Republic: Incorporating The Art of the Soluble and Induction and Intuition in Scientific Thoughtby Peter Medawar