He was so narrow-minded he could see through a keyhole with two eyes.
— Black Elk

What is a scientist after all? It is a curious man looking through a keyhole, the keyhole of nature, trying to know what's going on.
Jacques Yves Cousteau keyhole quote

Temptation is the devil looking through the keyhole. Yielding is opening the door and inviting him in.
— Billy Sunday

Every age has a keyhole to which its eye is pasted.
— Mary McCarthy

Scientists are peeping toms at the keyhole of eternity.
— keyhole quotation by Arthur Koestler