My sources of Free Thought are Alan Watts and Michel Martin.
I first learned about Free Thought in 1962, while serving in the US Army.
Edited transcript of my sources of freedom of thought shown in the link below.
Related article: https://medium.com/the-new-outdoors/the-origin-of-good-and-evil-80bb8f88bc23 The Origin of Good and Evil Danger, safety, ...