As a Naval Reserve officer, Livingston served in Okinawa and earned a Bronze Star during World War II.
His experience as a physician in a United States Navy hospital during the Atomic bombings of Hiroshima and Nagasaki lead him to a lifelong opposition to nuclear arms.
[4] He advised James Humes, the navy pathologist who performed the autopsy on John F. Kennedy, and based on his personal experience and observations became a skeptic of the "Lone gunman theory".
[2] After his time at the National Institutes of Health, in 1964 Livingston founded the neuroscience department, the first of its kind in the world, at the newly built University of California, San Diego campus.
He was active in the International Physicians for the Prevention of Nuclear War, which won the Nobel Peace Prize in 1985.