You can never learn less; you can only learn more.
Brain deals exclusively with the physical, and mind exclusively with the metaphysical.
It is essential that anyone reading this book know at the outset that the author is apolitical. I was convinced in 1927 that humanity's most fundamental survival problems could never be solved by politics.
Rashness is the faithful, but unhappy parent of misfortune.
Mistakes are great, the more I make the smarter I get.
Whatever humans have learned had to be learned as a consequence only of trial and error experience. Humans have learned only through mistakes.