“The difference between stupid and intelligent people – and this is true whether or not they are well-educated – is that intelligent people can handle subtlety.”

Source: The Long Dark Tea-Time of the Soul

Source: The Great Gatsby

Nobel Prize autobiography (1998)
Context: The world is full of intelligent, well-meaning people who, for one reason or another, did not attend university but are nonetheless well-read and educated. Out there on the prairie lost opportunities of youth were the rule rather than the exception, and I slowly became disabused of the myth of the Bright Young Thing and have not believed in it since.

On José Mourinho, (November 2005) http://news.bbc.co.uk/sport2/hi/football/teams/a/arsenal/4398238.stm
Context: He's out of order, disconnected with reality and disrespectful. When you give success to stupid people, it makes them more stupid sometimes and not more intelligent.

Variant: Intelligence plus character — that is the goal of true education.

Source: Derb Quotes https://www.nationalreview.com/corner/derb-quotes-john-derbyshire/, National Review, November 20, 2003.

Source: cited in Living Positive with Imperfection: A Memoir, September 15, 2017 https://books.google.com/books?id=hxU6CwAAQBAJ&lpg=PT231&ots=0nMTnr_TtC&dq=I%20know%20lots%20of%20people%20who%20are%20educated%20far%20beyond%20their%20intelligence.&pg=PT231#v=onepage&q=I%20know%20lots%20of%20people%20who%20are%20educated%20far%20beyond%20their%20intelligence.&f=false,

Source: High-Rise (1975), Ch. 8

Variant: The problem with the world is that the intelligent people are full of doubts, while the stupid ones are full of confidence.