In his 17 January 1889 letter to his brother Theo, an art dealer on whom he was financially dependent, Vincent van Gogh wrote of his poverty and his estrangement from Paul Gauguin, who for a time in 1888 had painted with van Gogh in the south of France. (Though van Gogh's paintings are now valued at millions of dollars, during his lifetime they earned him little.) As this letter reveals, van Gogh could not clearly understand why Gauguin had ended their friendship and returned to the north. Written just after van Gogh had returned to Aries from being hospitalized for psychological disorders and less than a year before his death by suicide, this letter is filled with evidence of the painter's emotional instability.

. . . It is unfortunately complicated in various ways, my pictiires are valueless, it is true they cost me an...