As nouns the difference between insanity and foolishness
is that insanity is the state of being insane; madness while foolishness is (uncountable) the state of being foolish.
insanity
Noun
The state of being insane; madness.
Antonyms
* sanity
Synonyms
* See also
Related terms
* insane
foolishness
Noun
(uncountable) The state of being foolish.
(countable) A thing or event that is foolish, or an absurdity.
Synonyms
* imprudence, folly
* extravagance, irresponsibility
* indiscretion, absurdity
* ridiculousness
* stupidity
Antonyms
* wisdom
Related terms
* fool