A bore is a man who deprives you of solitude without providing you with company.
Giovanni Vincenzo Gravina (1664-1718) Italian man of letters and jurist
(Attributed)
The actual provenance of this quotation is unknown. The earliest reference is in Reader's Digest (1949-03), where it is attributed by a contributor to Gravina, but identifying him as a contemporary author; the connection to the 18th Century Italian author and jurist is therefore tenuous.
Also attributed to Oscar Wilde (but not until long after his death), John C. MacDonald (who did use it, but attributed it to Gravina), and Roger Ebert (who did use it, but attributed it to John D. MacDonald).
A similar phrase can be found in Marcel Proust, The Captive [La Prisonnière], Part 1, ch. 1 (1923) [tr. Moncrieff (1929)] (Part 6 of his Remembrance of Things Past [A la Recherche du Temps Perdu]) [English, French]:Mamma would write to me: “Mme. Sazerat gave us one of those little luncheons of which she possesses the secret and which, as your poor grandmother would have said, quoting Mme. de Sévigné, deprive us of solitude without affording us company.”
[Maman m’écrivait : «Mme Sazerat nous a donné un de ces petits déjeuners dont elle a le secret et qui, comme eût dit ta pauvre grand’mère, en citant Mme de Sévigné, nous enlèvent à la solitude sans nous apporter la société.»]
More information and research into the quotation's origin can be found here: Quote Origin: A Bore Is a Person Who Deprives You of Solitude Without Providing You with Company – Quote Investigator®. QI says some very nice things about me and this site regarding the preliminary research I did on the question of authorship.

