In 1837, Stevens left middle school to begin study at the Académie Royale des Beaux-Arts in Brussels, where he knew François Navez, the
Neo-Classical painter and former student of Jacques-Louis David who was its director and an old friend of Stevens's grandfather.
In 1843, Stevens went to Paris, joining his brother Joseph who already was there. He was admitted to the École des Beaux-Arts, the most important art school in Paris. Although it is said that he became a student of its director
Jean Auguste Dominique Ingres, this is likely not true. An early picture by Stevens, The Pardon or Absolution -Hermitage, St. Petersburg, signed and dated 1849, shows his mastery of a conventional naturalistic style which owes much to 17th-century Dutch genre painting. Like the Belgian painter and friend with whom he stayed in Paris, Florent Joseph Marie Willems [
1823-1905], Stevens carefully studied works by painters such as Gerard ter Borch and Gabriel Metsu.