John M. Templeton Jr. speaks during a news conference in St. Paul's Cathedral in London before a ceremony to present the Dalai Lama with the 2012 Templeton Prize. (Oli Scarff/Getty Images)

John M. Templeton Jr., a former pediatric surgeon who was president and chairman of the John Templeton Foundation, a philanthropic organization that supports what it describes as “discoveries relating to the Big Questions of human purpose and ultimate reality,” died May 16 at his home in Bryn Mawr, Pa. He was 75.

The cause was cancer, according to a statement posted on the foundation’s Web site. The announcement of his death was delayed until after a ceremony for the Templeton Prize sponsored by the organization, which is based in West Conshohocken, Pa.

Dr. Templeton was director of the trauma program at Children’s Hospital of Philadelphia and retired from his medical practice in 1995 to manage the foundation. He became president and chief executive after the 2008 death of his father, Sir John Templeton, who created the Templeton Fund in 1954 and established the foundation in 1987.

During his 20 years at the helm, the foundation’s endowment grew from $28 million to $3.34 billion, with 188 grants awarded last year mainly to universities and scholars, according to the foundation.

The foundation awards an annual $1.7 million Templeton Prize to a living person “who has made an exceptional contribution to affirming life’s spiritual dimension, whether through insight, discovery, or practical works.”

The 2015 prize was awarded to Jean Vanier, founder of L’Arche, an international network of communities where people with and without intellectual disabilities live and work together.

John Marks Templeton Jr. was born in New York City on Feb. 19, 1940. He was a 1962 history graduate of Yale University and received a medical degree from Harvard University in 1968.

Survivors include his wife, Josephine “Pina” Gargiulo Templeton, whom he married in 1970; two daughters, Heather Dill and Jennifer Simpson; a brother; and six grandchildren.