Turning to the fair use question, the court first concluded that the full-text search function of the Hathitrust Digital Library was a “quintessentially transformative use,” and thus constituted fair use. The court said:the result of a word search is different in purpose, character, expression, meaning, and message from the page (and the book) from which it is drawn. Indeed, we can discern little or no resemblance between the original text and the results of the HDL full-text search.There is no evidence that the Authors write with the purpose of enabling text searches of their books. Consequently, the full-text search function does not “supersede[ ] the objects [or purposes] of the original creation.”Turning to the fourth fair use factor—whether the use functions as a substitute for the original work—the court rejected the argument that such use represents lost sales to the extent that it prevents the future development of a market for licensing copies of works to be used in full-text searches.However, the court emphasized that the search function “does not serve as a substitute for the books that are being searched.”