Sean Penn to Star in 'Professor & The Mad Man' with Mel Gibson

Sean Penn takes a seat and checks his phone after having dinner at Il Piccolino on Tuesday (August 23) in West Hollywood, Calif.

It was recently announced that the 56-year-old actor will star in The Professor and the Madman, according to THR.

Mel Gibson will also star in the film, adapted from the novel of the same name.

The Professor and the Madman follows a professor who begins work compiling words for the first edition of the Oxford English Dictionary in the mid 19th century and receives over 10,000 entries from a doctor at an insane asylum.