Question: Which person introduced Van Gogh to the art of painting?
About the article "Sien (Van Gogh series)", section "Estrangement from family".

Candidate passages:
Van Gogh saw "something deeper, more intimate, more eternal than the ocean in the expression of the eyes of a little baby when it wakes in the morning."
Infants which represented "rebirth and immortality" to Van Gogh and lightened his mood.
When he had the opportunity, Van Gogh enjoyed painting them. 
"Vase with Zinnias and Geraniums" (F241) reflects the influence of Adolphe Monticelli (1824–1886) in its vivid color and impasto paint.
Van Gogh admired, and later collected, Monticelli's work.
Van Gogh had been introduced by his brother Theo to Monticelli's still life work with flowers in Paris.
He admired Monticelli's use of color as an expansion of Delacroix's theories of color and contrast.
Secondly he admired the effect Monticelli created by heavy application of paint called "impasto".
It was partially Monticelli, from Marseilles, who inspired Van Gogh's southerly move to Provence in 1888.
He felt such kinship for the man, and desire to emulate his style, that he wrote in a letter to his sister Wil that he felt as if he were "Monticelli's son or his brother."
The first owner in the provenance of this painting is "C.M.
van Gogh Gallery, Amsterdam, The Netherlands", which was owned by Van Gogh's uncle and an art dealer, Cornelius Marinus van Gogh (1824–1908).
"Bowl with Zinnias and Other Flowers" (F251), painted within days of "Vase with Zinnias and Geraniums" (F241), is evidence of Van Gogh's transition to a lighter color palette.
Picking up elements of Impressionism Van Gogh painted with a more vigorous brushstroke, with thick application of paint, called "impasto" which created a three-dimensional relief.< 
As much as Van Gogh liked to paint portraits of people, there were few opportunities for him to pay or arrange for models for his work.
He found a bounty in the work of the Roulin family, for which he made several images of each person.
In exchange, Van Gogh gave the Roulin's one painting for each family member. 
In 1880 when he was 27 years-old, Van Gogh decided to become an artist.
In October of that year he moved to Brussels and began a beginner's course of study.
Van Gogh returned to Etten in April 1881 to live with his parents and studied art on his own.
His younger brother Theo, an art dealer at the main branch of Goupil & Cie, encouraged him and started covering Van Gogh's expenses.
Van Gogh used images from illustrated magazines to teach himself how to draw.
Charles Bargue, a French artist, wrote two books on drawing that were a significant source of study for Van Gogh.
Both written in 1871, one is "Cours de dessin" and the other "Exercises au fusain pour préparer à l’étude de l’académie d’après nature," Van Gogh created copies of the drawings or adapted nude images for clothed depictions.
In January 1882, he settled in The Hague where he called on his cousin-in-law, the painter Anton Mauve (1838–88).
Mauve introduced him to painting in both oil and watercolor and lent him money to set up a studio.
Van Gogh began drawing people from the working poor, including the prostitute Clasina Maria "Sien" Hoornik (1850–1904, with whom he would become involved.
Van Gogh dreamed his studio would one day become a form of respite for the poor where they could receive food, shelter and money for posing.
His work was not well received; Mauve and H.G.
Tersteeg, manager of Goupil & Cie, considered the drawings coarse and lacking charm.
Van Gogh likened the subjects "unrefined" characteristics of his drawings to harsh "yellow soap" made of lye.
Van Gogh's relationship with Sien changed as they lived together with Maria, her five-year-old daughter, to the great disappointment of his family.
Mauve appears to have suddenly gone cold towards Van Gogh and did not return a number of his letters, Van Gogh supposed that Mauve did not approve of his domestic arrangement with Sien and her young daughter.
Van Gogh created a number of drawings of Sien and her daughter.
Having ended his relationship with Sien, Van Gogh moved to Drenthe in September 1883 and painted landscapes.
Three months later, he moved back in with his parents, who were at that point living in Nuenen.
In 1884, Van Gogh created the weaver series, works of rural life and landscapes.
For a brief period of time, he gave painting lessons in Eindhoven.
Near the end of the year, Van Gogh began experimenting with complementary colors, influenced by the color theories of Charles Blanc.
Vincent made many studies of peasants in 1885, culminating in his first major painting, "The Potato Eaters."
In his works, Van Gogh used particularly somber colors and colors mixed with black, which he felt was like that of 17th-century masters, such as Frans Hals.
His brother, Theo van Gogh (art dealer) had asked him often to lighten up his work, referring to the work of the Impressionists.
Once Van Gogh went to Paris, he did open up his palette to color and light and admitted that his works from this period were old-fashioned.
Theodorus van Gogh, Vincent's father, died March 26, 1885.
In November, Vincent moved to Antwerp. 
Van Gogh painted the family of postman Joseph Roulin in the winter of 1888, every member more than once.
The family included Joseph Roulin, the postman; his wife, Augustine; and their three children.
Van Gogh described the family as "really French, even if they look like Russians."
Over the course of just a few weeks, he painted Augustine and the children several times.
The reason for multiple works was partly so that the Roulins could have a painting of each family member, so that with these pictures and others, their bedroom became a virtual "museum of modern art."
The family's consent to modeling for van Gogh also gave him the opportunity to create more portraits, which was both meaningful and inspirational to van Gogh.
Van Gogh used color for dramatic effect.
Each family member's clothes are done in bold primary colors and van Gogh used contrasting colors in the background to intensify the impact of the work.