Outspoken Maoist scholar Sima Nan is again in the public eye but not for something he said. This time the cause of debate is a shoe that was hurled at him during his address at Hainan University on Sunday.

During Sima's Q&A portion of his lecture, a young man stood up and said he feared being punished if he attempted to refute Sima's "politically correct" speech. He then asked Sima if he could throw his shoe at him. The man did not wait for a reply and the shoe missed its target by about two meters.

A video clip on Sina Weibo shows the audience applauding the man's shoe toss. The university's president, Li Jianbao, can be heard demanding to know the show-thrower's class as he is being escorted out of the room by staffers.

Sima said Monday on his Sina Weibo that more than 10 people were stopped from entering his lecture when they were discovered to be carrying stones and eggs.

"This violates pubic order and stoops to the bottom line of civilization," Sima wrote. 

The incident highlights what appears to be a growing vitriolic debate between the left and the right in China, which many hope will cool down. 

An opinion piece on the news portal jsnews.com declared that the people have the right to express themselves, "Although Sima has been tagged as a leftist, he still has the right to express his ideas and people have the right to criticize him. This debate must be conducted with decorum."

Sima has written controversial books and commentaries defending the Chinese political system and criticizing the West.

Calls to Sima and the university president's office went unanswered.