“Literature as a whole is not an aggregate of exhibits with red and blue ribbons attached to them, like a cat-show, but the range of articulate human imagination as it extends from the height of imaginative heaven to the depth of imaginative hell.”

Lecture: The Lost Arts, reported in Bartlett's Familiar Quotations, 10th ed. (1919)

"Quotes", The Educated Imagination (1963), Talk 4: The Keys To Dreamland

As quoted in A Dictionary of Thoughts : Being a Cyclopedia of Laconic Quotations from the Best Authors, Both Ancient and Modern (1891) edited by Tryon Edwards. p. 327.
1890s and attributed from posthumous publications

"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.

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.

Speech in the Guildhall, London, on the Indian Mutiny (9 November 1857), quoted in The Times (10 November 1857), p. 7
1850s