The Lesson is a 1950s absurdist play with a theme that is relevant even today. Eugene Ionesco has skillfully camouflaged political criticism and philosophical thought in the garb of wit and comedy. There are only three characters: the brusque Maid, the earnest Pupil, and the intense Professor. The play is set in the Professor's apartment. The Pupil comes for her lesson in the hope of earning her doctorate. The Professor, a caricature of an academic personality, attempts to help her.

Soon, the student's spontaneous and instinctive methods clash with the Professor's intellectual approach and the result is complete chaos. In his efforts to teach the Pupil the fundamental principles of mathematics, the Professor confuses her. Gradually, the lesson makes little or no sense to her. As the Professor gets intimidating, the unhappy Pupil starts suffering from a toothache. In the face-off between the teacher and the student, we observe the chasm that lies between knowledge and the ability to grasp that knowledge.

At the climax of the play, the frustrated Professor murders the student. The play ends with the Maid greeting a new pupil. The conclusion conjures a vision of another hapless pupil who is striving to learn the lessons of life. The play criticizes the tendency to enforce compliance and destroy dissension. It comments on the dangers of blind authority and demagoguery.