Gaston Cleric is Jim's teacher and close mentor in college. We don't know too much about him, other than that he teaches Jim to appreciate Latin. Jim is impressed with Cleric's intellectual prowess and his ability to appreciate beauty. Jim tells us that Gaston very nearly missed being a poet. It is also Gaston who saves Jim from the temptation of Lena. The tutor sweeps him off to Harvard, where he can focus on his studies. Sadly, Gaston ends up dying of pneumonia.