"Science-fiction is the law-abiding citizen of imaginative literature, obeying the rules, be they physical, social, or psychological, keeping regular hours, eating punctual meals; predictable, certain, sure.

Fantasy, on the other hand, is criminal. Each fantasy assaults and breaks a particular law; the crime being hidden by the author's felicitous thought and style which cover the body before blood is seen.

Science-fiction works hand-in-glove with the universe.

Fantasy cracks it down the middle, turns it wrong-side-out, dissolves it to invisibility, walks men through its walls, and fetches incredible circuses to town with sea-serpent, medusa, and chimera displacing zebra, ape, and armadillo.

Science-fiction balances you on the cliff.

Fantasy shoves you off. "

Quotations by Ray Bradbury - from the Introduction to The Circus of Dr. Lao