The universe is a closed room without windows, yet with movable shelves and boxes stuffed with anachronistic books and racks. Knowledge is always fragmentary, dynamic, only temporarily sedimentary and thus it lies on the racks. Someday, there'll be on the shelves, ours, the only virtual volume of truth with its multiple entries that makes up for the only truth of everything. Shelves, a conceptual dictionary, tries to define and entwine the many different concepts that, altogether, conform the ordered whole, opening at the same time, new perspective and consideration to everything that surrounds and contains us, notwithstanding preconceptions and the mainstream. We are on our way to master the universe. Let us be patient. Or not.