The artist and the medium are alike. Both channel atmosphere, emotion, and the subconscious. Both are committed to their visions. The exhibition “Not Without My Ghosts” begins with William Blake in the Romantic era and the Victorian women known as “spirit artists”—Georgiana Houghton, Anna Mary Howitt, and Barbara Honywood—all of whom painted their communications with the otherworldly. In the 20th century the Surrealists experimented with automatism, those brief entrancements when the unconscious takes hold. And contemporary artists have not shied from cosmology and clairvoyance. We all love a ghost story and this one presents the work of 26 artists from the last two centuries. —E.C.