I totally get the hunt for Manly P. Hall’s works. His books, like 'The Secret Teachings of All Ages,' are treasure troves of wisdom, but finding free PDFs can be tricky. Websites like Project Gutenberg or Open Library sometimes have older, public-domain titles, but many of his works are still under copyright. I’ve found that smaller occult forums or academic sharing platforms occasionally have PDFs, but quality varies.
If you’re serious about studying his work, investing in physical copies or official e-books is worth it—they often include annotations and better formatting. Some universities also offer digital access through their libraries if you’re a student. Just remember, supporting authors (or their estates) ensures more great content keeps coming!