The quote comes from Thomas Edison, according to former AOL co-founder Steve Case. He was interviewed in the New York Times “Corner Office” column and when asked what some of his early leadership issues were, he replied:

“The core one is a Thomas Edison quote that summarizes my perspective on things, which is, ‘Vision without execution is hallucination.’ I do believe in vision. I do believe in big ideas. I do believe in tackling problems that are complex and fighting battles that are worth fighting, and also trying to, in my case, create companies or back companies. That can change the world. The vision thing is really important — but the execution thing is really important, too. Having a good idea is not enough. You’ve got to figure out some way to balance that and complement that with great execution, which ultimately is people and priorities and things like that. You have to strike the right balance. If you have those together, I think anything is possible. If you don’t have both of them working together in a complementary, cohesive way, you’re not going to be successful.”

See the full interview in the New York Times.