Timothy Ferriss is an American entrepreneur, investor, author, podcaster, and lifestyle guru. He is known for his 4-Hour self-help book series—including The 4-Hour Work Week, The 4-Hour Body, and The 4-Hour Chef—that focused on lifestyle optimizations, but he has since reconsidered this approach.

Ryan Holiday is an American marketer, author, businessman and podcaster, notable for marketing Stoic philosophy in the form of books.