University of California Berkeley’s mathematics professor Alexander Coward bravely emailed students that his class would still be held, even though it meant crossing a union’s picket line.

And while students normally enjoyed a day off, his action was completely supported by them and his email drew a lot of praise after it went viral.

What could make a professor more popular than calling off class to support a social movement? At the University of California at Berkeley, an instructor has seen his email message to students about not canceling class go viral — with largely positive reactions and some criticism as well.

Alexander Coward, a lecturer in mathematics, emailed his freshman calculus class last week to confirm that class would not be canceled — despite a union protest that drew the support of many professors and graduate student instructors who did call off class.

“Whatever the alleged injustices are that are being protested about tomorrow, it is clear that you are not responsible for those things, whatever they are, and I do not think you should be denied an education because of someone else’s fight that you are not responsible for,” he wrote in the email.

Members of the university’s largest employee union, which represents the university’s service, skilled craft and patient care workers, were joined by some faculty members, students and staff in protesting what they consider to be unsafe staffing levels at the University of California’s hospitals and campuses’ health care clinics, said Todd Stenhouse, a spokesman for the union, AFSCME 3299.

Coward’s email has attracted praise not so much for his decision not to honor the strike, but for what he said about education. He discussed students’ responsibility to invest in their own education (both inside and outside of a classroom setting) as a means to “navigate the increasing complexities of the 21st century.” He said he thought it would be more valuable to teach rather than protest, but stressed he respected the decision of those who participated in the protest. He also wrote in the email that he was covering the sections for two graduate student instructors who were joining the picket line.

“And do not fall into the trap of thinking that you focusing on your education is a selfish thing,” Coward wrote. “It’s not. It’s the most noble thing you could do.” He continued: “Society is investing in you so that you can help solve the many challenges we are going to face in the coming decades, from profound technical challenges to helping people with the age old search for human happiness and meaning. That is why I am not canceling class tomorrow.”

Coward said he’s received “very touching” emails from people all over the world who have thanked him for pointing out the importance of education. His students told him the main take-away from the email is that valuing education is not selfish.