Shelves of law books are an august symbol of legal practice, and no place, save the Library of Congress, can match the collection at Harvard’s Law School Library. Its trove includes nearly every state, federal, territorial and tribal judicial decision since colonial times — a priceless potential resource for everyone from legal scholars to defense lawyers trying to challenge a criminal conviction.

Now, in a digital-age sacrifice intended to serve grand intentions, the Harvard librarians are slicing off the spines of all but the rarest volumes and feeding some 40 million pages through a high-speed scanner. They are taking this once unthinkable step to create a complete, searchable database of American case law that will be offered free on the Internet, allowing instant retrieval of vital records that usually must be paid for.

“Improving access to justice is a priority,” said Martha Minow, dean of Harvard Law School, explaining why Harvard has embarked on the project. “We feel an obligation and an opportunity here to open up our resources to the public.”

For many years now, bookcases of legal tomes in law offices have been mostly for show. Rather than spending days poring over book indexes and footnoted citations, as law clerks and associates did in earlier times, researchers find what they need on the Internet in minutes. But that nearly always comes at a price.