My addition to this most impressive sounding list would be the True Believer by Eric Hoffer. This 1950s gem of a book lays out the fundation psychology of mass movements of religion and politics. What drives folks to become fanatical followers of causes, to almost mindlessly submit one’s self to doctrine and ideology. Over the years It has become my Bible for understanding human nature.
Then of course I can’t resist suggesting by own modest contribution to grappling with the human condition, A Quick Look at the Essence of Man and His Universe.