" On your planet you have an animal called a bear. It is a large animal, sometimes larger than you, and it is clever and has ingenuity , and it has a brain as large as yours. But the bear differs from you in one important way. It cannot perform the activity you call imagining. It cannot make mental images of how reality might be. It cannot envision what you call the past and what you call the future. This special ability of imagination is what has made your species as great as it is. Nothing else. It is not your ape-nature, not your tool-using nature, not language or violence or caring for your young or social groupings. It is none of these things, which are all found in other animals. Your greatness lies in imagination.
The ability to imagine is the largest part of what you call intelligence. You think the ability to imagine is merely a useful step on the way to solving a problem or making something happen. But imagining something is what makes it happen.
This is the gift of your species and this is the danger, because you do not control your imaginings. You imagine wonderful things and you imagine terrible things, and you take no responsibility for the choice. You say you have inside you the power of good and the power of evil, the angel and the devil, but in truth you have just one thing inside you - the ability to imagine. "
