REALITY+: Virtual Worlds and the Problems of Philosophy, by David J. Chalmers. (Norton, $32.50.) A philosopher argues in favor of embracing digital worlds and employs virtual reality technology to reach new insights on longstanding philosophical questions. THE VANISHED COLLECTION, by Pauline Baer de Perignon. Translated by Natasha Lehrer. (New Vessel, paper, $17.95.) De Perignon’s debut recounts her quest to recover her family’s art collection after learning that paintings owned by her great-grandfather may have been stolen by Nazis in World War II. WORN: A People’s History of Clothing, by Sofi Thanhauser. (Pantheon, $30.) This diligently reported account of human clothing covers the history of textiles in five stories — linen,…