Gordon Mortrude challenged teachers to treat their students with respect and kindness, even at times when students were acting out.

This was back in the mid-1960s, before that approach had a name and before school districts and teachers across the country were grappling with ways to discipline students in less punitive ways.

"He was a big fan of using humor and being generous with students," said Mark Mortrude, Gordon's eldest son.

Gordon Mortrude died of natural causes July 8 at 87.

Mortrude, a Greenbush native, began his teaching career at Sauk Rapids High School and later went on to teach in San Bernardino, Calif.

In 1990, he moved back to Minnesota to become a professor at St. Cloud State University's School of Education. Mortrude held a doctoral degree in teacher education.

Mark Mortrude said his father's most popular class delved into the difficult subject of student discipline and school culture.

Future educators would discuss how they would discipline a child in various situations. Still, regardless of the infraction, Mark said his father always believed in rewarding positive behavior.

"When you catch them doing something right, invest in that positive behavior so that when you do have to call them out on something, they know you care about them," Mark said his father would tell his students.

Mortrude's daughter Jody Anderson took his class when she was studying to be a teacher. On the first day of class, they would write down a situation they had already encountered in the classroom on an index card.

Then Mortrude would randomly pick out a "situational card," and everyone in the class would describe how they would handle that situation.

"It was very real. That's what students appreciated so much," Anderson said.

Today, many districts across the country, including Minneapolis and St. Paul, are implementing Positive Behavior Interventions and Supports (PBIS), a tool kit that aims to reduce suspensions and other punitive discipline tactics by rewarding good behavior, creating school mottos and implementing exercise programs in schools.

Mark said his father began teaching some of the same concepts before PBIS got its name in the 1990s.

"We all need to have our steering corrected from time to time, but he taught that there are more humane ways of doing it, other ways to correct behavior and have a more positive experience with kids," Mark said.

In 1990, Mortrude retired, but he continued to speak to future teachers about the best strategies for their classrooms. He worked for several years as a consultant in education and the private sector.

His passion for education was passed down to his four children, who all went on to become teachers or work in school districts.

Rana Nestrud, his youngest daughter, said she knew she wanted to be a teacher from the time she was in kindergarten. Though Mortrude did not insist on his children becoming educators, he always spoke highly of the teachers he had growing up.

"As a young child, I remember knowing that education was a gift," Nestrud said.

Mortrude's lectures and classes were in high demand both on and off campus. He was invited to Alaska and Arizona to talk to educators on Indian reservations.

Still, his children remember him most as a loving father who never missed dinner with Thelma, his wife of 69 years.

In addition to his wife, Mortrude is survived by children Jody, Scott, Mark and Rana and four grandchildren. Services have been held.