Scott Gerber, a law professor at the Ohio Northern University Pettit College of Law, was pulled from his classroom last month, banned from campus and allegedly forced to sign a separation agreement—and he says he doesn’t know why. Now the school is seeking his dismissal.

“Ohio Northern University is trying to banish me for lack of ‘collegiality’ but won’t say what I’ve done,” Gerber wrote in an op-ed published on May 9 in the Wall Street Journal.