Goodwill, in fact, is mainly what this muted drama has, along with premises that suggest a therapeutic fairy tale and the warmth of Gus Van Sant’s laid-back direction. Young mathematics genius Will Hunting (cowriter Matt Damon) works as a janitor at MIT, where a math professor (Stellan Skarsgard) discovers him and makes him see a therapist (a subdued Robin Williams). Scripted with Ben Affleck (who plays the hero’s best friend), and assisted by a charismatic performance by Minnie Driver, this is good, solid work that never achieves either the art or poignance of Van Sant’s earlier and more personal projects (Mala Noche, Drugstore Cowboy, My Own Private Idaho), though it’s clearly superior to something like Dead Poets Society. 126 min. (JR)