From comments on everything from artificial intelligence to street smarts, these great thinkers had something to say about intelligence.

1. "No tool is more beneficial than intelligence. No enemy is more harmful than ignorance."
-- Abu Abdullah Muhammad al-Harithi al-Baghdadi al-Mufid (lived 10th century), Iraqi scholar and jurist. From The Book of Guidance into the Lives of the Twelve Imams,  "The Life of the Commander of the Faithful" (I. K. A. Howard [tr.]).

2. "Computers double their performance every 18 months. So the danger is real that they could develop intelligence and take over the world."
-- Stephen Hawking (1942 - ), British physicist.

 

3. "The world of the future will be an ever more demanding struggle against the limits of our intelligence, not a comfortable hammock in which we can lie down to be waited upon by our robot slaves."
-- Norbert Wiener (1894 - 1964), U.S. mathematician.

4. "It takes a lot of time to be a genius; you have to sit around so much doing nothing, really doing nothing."
-- Gertrude Stein (1874 - 1946), U.S. writer.

 

5. "Intellect is invisible to the man who has none."
-- Arthur Schopenhauer (1788 - 1860), German philosopher.

 

6. "I'm not smart. I try to observe. Millions saw the apple fall but Newton was the one who asked why."
-- Bernard Mannes Baruch (1870 - 1965), U.S. financier, statesman, and philanthropist. The New York Post.

7. "The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function."
-- F. Scott Fitzgerald (1896 - 1940), U.S. writer.

 

8. "We may have trouble defining intelligence but we recognize it when we see it."
-- Steven Pinker (1954 - ), U.S. cognitive scientist and author.

9. "Great Wits are sure to Madness near alli'd
     And thin Partitions do their Bounds divide."
-- John Dryden (1631 - 1700), English poet, playwright, and literary critic.

 

10. "Intelligence is almost useless to the person whose only quality it is."
-- Alexis Carrel (1873 - 1944), French biologist and surgeon.