Hugo Boxel was the author of Ep51, 53, and 55 to Spinoza, and the recipient of Ep52, 54, and 56. This correspondence took place from September to October/November 1674 and suggests the two had met before and conversed. It covers the unlikely topic of apparitions and ghosts and has often been regarded as one of the oddest episodes in Spinoza’s correspondence, although during the second half of the seventeenth century the belief in ghosts, witches, and magic was still widespread across Europe; the Dutch Republic was no exception.