stylistic:tone
Letters

The most comprehensive primary source on van Gogh is his correspondence with his younger brother, Theo. Their lifelong friendship, and most of what is known of Vincent's thoughts and theories of art, are recorded in the hundreds of letters they exchanged from 1872 until 1890. Theo van Gogh was an art dealer and provided his brother with financial and emotional support as well as access to influential people on the contemporary art scene.

Theo kept all of Vincent's letters to him; but Vincent kept only a few of the letters he received. After both had died, Theo's widow Jo Bonger-van Gogh arranged for the publication of some of their letters. A few appeared in 1906 and 1913; the majority were published in 1914. Vincent's letters are eloquent and expressive, have been described as having a "diary-like intimacy", and read in parts like autobiography. Translator Arnold Pomerans wrote that their publication adds a "fresh dimension to the understanding of van Gogh's artistic achievement, an understanding granted to us by virtually no other painter".

There are more than 600 letters from Vincent to Theo and around 40 from Theo to Vincent. There are 22 to his sister Wil, 58 to the painter Anthon van Rappard, 22 to Émile Bernard as well as individual letters to Paul Signac, Paul Gauguin, and the critic Albert Aurier. Some are illustrated with sketches. Many are undated, but art historians have been able to place most in chronological order. Problems in transcription and dating remain, mainly with those posted from Arles. While there, Vincent wrote around 200 letters in Dutch, French, and English. There is a gap in the record when he lived in Paris as the brothers lived together and had no need to correspond.

The highly paid contemporary artist Jules Breton was frequently mentioned in Vincent's letters. In 1875 letters to Theo, Vincent mentions he saw Breton, discusses the Breton paintings he saw at a Salon, and discusses sending one of Breton's books but only on the condition that it be returned. In a March 1884 letter to Rappard he discusses one of Breton's poems that had inspired one of his paintings. In 1885 he describes Breton's famous work The Song of the Lark as being "fine". In March 1880, roughly midway between these letters, Van Gogh set out on an 80-kilometre trip on foot to meet with Breton in the village of Courrières; however, he was intimidated by Breton's success and/or the high wall around his estate. He turned around and returned without making his presence known. It appears Breton was unaware of van Gogh or his attempted visit. There are no known letters between the two artists and van Gogh is not one of the contemporary artists discussed by Breton in his 1891 autobiography Life of an Artist.