The real story

No credible evidence places this phrase with Thomas Edison. The earliest documented source is Jeffrey E. Garten's 2001 book "The Mind of the CEO," where Stephen Case, then Chairman and CEO of America Online, is quoted saying: "In the end, a vision without the ability to execute it is probably an hallucination." The attribution to Edison began circulating around 2006 without any documentary basis. The quote is also sometimes attributed to Walter Isaacson, who used a similar formulation in his biographical writings, further muddying the trail. Wikiquote's Thomas Edison talk page explicitly notes no credible evidence for the Edison attribution. The Japanese proverb "Vision without action is a daydream" expresses a related concept but is a distinct saying.