The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.

after Bertrand Arthur William Russell, 3rd Earl Russell – British philosopher and mathematician, Nobel Prize in literature 1950 (1872-1970)), freely after a quote from his collection of essays “Mortals and Others: American Essays” (1931-35)

The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.