https://www.feynmanlectures.caltech.edu/I_03.html
Lecture #3
Exciting stuff
The Value of Science
https://khoitsmahq.firstcloudit.com/images/feynman.pdf
A sober lecture
Excerpts
To every man is given the key to the gates of heaven; the same key opens the gates of hell.
…
When we read about this in the newspaper, it says “Scientists say this discovery may have importance in the search for a cure for cancer.” The paper is only interested in the use of the idea, not the idea itself. Hardly anyone can understand the importance of an idea, it is so remarkable. Except that, possibly, some children catch on. And when a child catches on to an idea like that, we have a scientist. It is too late for them to get the spirit when they are in our universities, so we must attempt to explain these ideas to children.
End of Excerpts
Link to the Official Feynman Lecture Site
https://www.feynmanlectures.caltech.edu/
A treasure trove
Bonus — Four Lectures
https://www.feynmanlectures.caltech.edu/TIPS_01.html
All of these are so well done
https://www.feynmanlectures.caltech.edu/TIPS_02.html
https://www.feynmanlectures.caltech.edu/TIPS_03.html
“Remember: Whenever you’re stuck in a mathematical analysis, you can always do it by arithmetic!”
https://www.feynmanlectures.caltech.edu/TIPS_04.html