“All human accomplishment has the same origin, identically. Imagination is a force of nature. Is this not enough to make a person full of ecstasy? Imagination, imagination, imagination. It converts to actual. It sustains, it alters, it redeems!”

Opus Posthumous (1955), Adagia

Address http://www.ted.com/talks/james_cameron_before_avatar_a_curious_boy.html/ to the 2010 TED conference (13 February 2010)
Context: Imagination is a force that can actually manifest a reality. … Don’t put limitations on yourself. Other people will do that for you. Don’t do that to yourself. Don’t bet against yourself. And take risk. NASA has this phrase that they like, "Failure is not an option." But failure has to be an option. In art and exploration, failure has to be an option. Because it is a leap of faith. And no important endeavour that required innovation was done without risk. You have to be willing to take those risks. … In whatever you are doing, failure is an option. But fear is not.

"Quotes", The Educated Imagination (1963), Talk 1: The Motive For Metaphor http://northropfrye-theeducatedimagination.blogspot.ca/2009/08/1-motive-for-metaphor.html
Context: At the level of ordinary consciousness the individual man is the centre of everything, surrounded on all sides by what he isn't. At the level of practical sense, or civilization, there's a human circumference, a little cultivated world with a human shape, fenced off from the jungle and inside the sea and the sky. But in the imagination anything goes that can be imagined, and the limit of the imagination is a totally human world.

Book X, Chapter VII, 15
De Institutione Oratoria (c. 95 AD)

Source: World War Z: An Oral History of the Zombie War

The Value of Science (1955)

Amusing Ourselves to Death: Public Discourse in the Age of Show Business (1985)
Context: In a world populated by people who believe that through more and more information, paradise is attainable, the computer scientist is king. But I maintain that all of this is a monumental and dangerous waste of human talent and energy. Imagine what might be accomplished if this talent and energy were turned to philosophy, to theology, to the arts, to imaginative literature or to education? Who knows what we could learn from such people — perhaps why there are wars, and hunger, and homelessness and mental illness and anger.

Source: Talk to the Hand: The Utter Bloody Rudeness of the World Today, or Six Good Reasons to Stay Home and Bolt the Door

"G. B. S. — Mark V", in I Sing the Body Electric: And Other Stories (1998)
Context: We are the miracle of force and matter making itself over into imagination and will. Incredible. The Life Force experimenting with forms. You for one. Me for another. The Universe has shouted itself alive. We are one of the shouts.