I believe this is from someone on this site :
"The problem with the unobservable and the undetectable is that they are indistinguishable from the non-existent."
Sheperd Book, from Firefly (TV series) :
"Governments are groups of people, usually notably ungoverned."
Someone :
"Lazy is a word we use when someone isn't doing what we want them to do."
My favourite Churchill quote, although for the wrong reasons (1919):
"I am strongly in favour of using poisoned gas against uncivilised tribes. The moral effect should be so good that the loss of life should be reduced to a minimum. It is not necessary to use only the most deadly gasses: gasses can be used which cause great inconvenience and would spread a
lively terror and yet would leave no serious permanent effects on most of those affected."
(italics mine)