BRAINTREE -- For 41 seasons as the head football coach at Boston Catholic High School, Jim Cotter rallied his teams to face some of the toughest competition in the state of Massachusetts. More than just the game, he taught his players how to battle and be successful in life.

Today, as the entire school community rallies around him, he is once again teaching others how to face adversity through his own personal example.

“Now, for the first time in his life, he is fighting a losing battle against a tougher opponent,” reads the dust jacket of his recently-penned memoir. “Coach is stricken with ALS, better known as Lou Gehrig’s Disease, but Jim Cotter intends to do what he has always done, battle with dignity and honor until the end.”

In February, BC High hosted a book-signing for the memoir, entitled “A True Man For Others: The Coach Jim Cotter Story” which Cotter co-wrote with Paul Kenney, currently a sports writer for the Patriot Ledger and one of Cotter’s former students.

Kenney said that proceeds from book sales raise money for ALS research and equipment for its patients, a portion of Cotter’s medical expenses, and the scholarship fund at BC High named in his honor, which helps students attend BC High.

“He’s always looking out for the underdog -- a kid with brainpower but not a lot of money,” said Kenney.

Cotter said that his book sold about 700 copies at the signing this winter.

The book details Cotter’s upbringing in Savin Hill, his time as a student-athlete at BC High and Boston College, his tenure as BC High’s head football coach, his personal and family life, and his insights into his fight with ALS.

Cotter was born in 1937. He graduated college in 1959 and started teaching history at BC High that fall. During his tenure at the Dorchester school, he also served as a guidance counselor and baseball coach.

He became head football coach in 1964 and compiled a 236-149-17 record, winning state championships in 1977 and 2000. He retired in 2004 and was diagnosed with ALS in October 2006.

Cotter called his progression “relatively slow,” though he said he does not have use of his arms and legs, his muscles have begun to deteriorate, and his speech has weakened.

Cotter said that when he was diagnosed, the doctor told him the disease takes three years to fully progress. He has been living with ALS for four years.

“I guess I beat the odds,” Cotter said.

Today, Cotter, who uses an electric wheelchair, watches BC High football games from his van parked near the end zone. His grandson is a quarterback on the team.

“It’s like I’m in a box seat,” he said.

Jon Bartlett, the current BC High head football coach and one of Cotter’s former players, points to his former mentor’s toughness.

“Knowing who Coach Cotter is ... you didn’t expect any other way for him to handle this,” Bartlett said. “That’s just who he is. He’s such a strong person.”

Leo Smith, one of Cotter’s former players and a 1978 graduate of BC High, credits Cotter for not having a “woe is me” attitude.

“This disease will not beat him,” Smith said. “He’s the guy who wakes up and gets the most out of each day.”

Cotter said he is frequently visited by friends and family, including former assistant coaches and players. He also goes out for lunch once a week, he said.

“I’ve never been depressed for one day and I never will be,” Cotter said. “I’ve lived a good life. I’ve had 44 years at the best school in the country.”