Joe Clark, the former high school principal and educator depicted in the movie “Lean on Me,” will speak at Gonzaga University on Wednesday.

A former Army drill instructor, Clark is known for the disciplinary steps he took as the principal of Eastside High in Paterson, N.J. On his first day in September 1983, a stabbing took place at school. After two years of Clark’s leadership, Eastside High was declared a model school by New Jersey’s governor. President Reagan also named him a model educator.

His book, “Laying Down the Law,” explains his emphasis on discipline and his desire to challenge students and to confront those who misbehave.

Admission costs $2 for his 8 p.m. speech, “From Disgrace to Amazing Grace.”