The Jeff Cooper Legacy Foundation https://jeffcooperfoundation.org/ has made available, as a free PDF download, Jeff Cooper’s short book, Principles of Personal Defense https://jeffcooperfoundation.org/?page_id=1546 The download link is at the bottom of the page.

You now have no excuse for not reading it. It is a short book and well worth an hour or so of your time.

Many thanks to Greg Moats for the heads-up.