Vincent van Gogh's "finest letter in private hands", written less than seven months before his tragic death in 1890, will go under the hammer at an online auction, estimated to bring up to US$300,000.

While the key to understanding van Gogh as an artist is arguably the famous collection of letters between him and his younger brother, art dealer Theo van Gogh, the letter put up for sale, addressed to his close friends Joseph and Marie Ginoux, is of no minor importance. 

In this highly personal letter to the owners of the Cafe de la Gare in Arles, where van Gogh lived, the genius artist, famous for cutting off his own ear, describes his failing mental and physical health with clarity and self-awareness. 

“Disease exists to remind us we are not made of wood…” the childless painter, who viewed his creations as his progeny, wrote. During his short life, which ended when the creator of the "Painter on the Road to Tarascon" shot himself dead aged 37, van Gogh suffered from depression and would be probably diagnosed with bipolar disorder these days. 

A year before his death, in 1889, the residents of Arles called on local authorities to have him put into an asylum, claiming the painter appeared to be a public menace. Later van Gogh entered the mental asylum for the second time, this time voluntarily. What mattered was that at Saint-Rémy he was allowed to paint and could therefore better control his hallucinations.

The antique letter will be among 300 historical documents offered by "Profiles in History" in an online and phone auction on December, 18.  

It's expected to fetch between $200,000 and $300,000, a modest price for the artifact by one of the greatest painters in history. Although during his lifetime Van Gogh sold only one painting, in the 20th century his creations became among the world's most expensive paintings. His "Portrait of Doctor Gachet" sold for $82.5 million in 1990.

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