A large part of the personal library of the Greek philosopher Aristotle (384–322 B.C.E.) may have been acquired by the Ptolemies for the library at Alexandria.

Aristotle was closely linked to Alexander the Great, founder of Alexandria. Not only was Aristotle’s father the personal physician of Alexander’s father, Philip of Macedon, but Aristotle—who had studied under Plato—became Alexander’s tutor. Ptolemy I (c. 367–283 B.C.E.), the first king of the Egyptian Ptolemaic dynasty, even encouraged the story that Aristotle, too, was the son of Philip.1

As tutor to Alexander and later as head of the Lyceum in Athens, Aristotle had a greater opportunity than most to acquire books. His library would have reflected the talents and interests of a scholar of universal learning; it would also have included the 400 or so books authored by Aristotle himself.2

When Aristotle died, he left his library, including his own recension (or edited text) of Homer and the original manuscripts of his other writings, to his successor at the Lyceum, Theophrastus of Lesbos. Theophrastus, in turn, left the library to his relative and pupil, Neleus of Scepsus.3 Fearing that the Attalid kings of Pergamum would confiscate the collection for their own famous library, Neleus stored the books in a damp cave, where some of the manuscripts moldered. He later sold most of the library to Ptolemy II (308–246 B.C.E.) for the Alexandria Library; the rest of it was sold to the Apellicon Library of Athens.

Where is Aristotle’s library today? Because of a curious convergence of historical events, manuscripts from the library Neleus sold to the Apellicon Library and to the Alexandria Library may now be in the Vatican Library.

In 84 B.C.E., the Roman general Sulla confiscated the Apellicon’s collection and transported it to Rome.4 Part of that collection may later have been incorporated into the Vatican’s holdings. There is also reason to believe that manuscripts from the Alexandria Library, including perhaps some of Aristotle’s books, may have ended up in Rome as well—in those centuries when the Roman emperors received huge caches of books from Alexandria as bounty. Is it possible that a good portion of Aristotle’s library still rests unknown in a corner of the Vatican Library?