Man has made use of his intelligence, he invented stupidity. – Remy de Gourmont

The doctrine of human equality reposes on this: that there is no man really clever who has not found that he is stupid. – G. K. Chesterton

Intelligence is quickness to apprehend as distinct form ability, which is capacity to act wisely on the thing apprehended. – Alfred North Whitehead

It is an accepted commonplace in psychology that the spiritual level of people acting as a crowd is far lower than the mean of each individuals intelligence or morality. – Christian Lous Lange