Albert Einstein and the Atomic Bomb

A Convinced Pacifist

Einstein's in-depth letter to Kaizō was undoubtedly spurred by the emotional effect of the publication of photos of the devastation at Hiroshima and Nagasaki.  In it, he explained that, despite his position as a "convinced pacifist," he saw no way to avoid destruction, aside from the world undertaking a "radical abolition of war."

This statement sparked a series of six letters between Einstein and Japanese philosopher Seisei Shinohara, whose argument hinged on the term "convinced pacifist," which Shinohara read as "absolute pacifist."

As Einstein would clarify in a February 23, 1953, letter to Shinohara, "While I am a convinced pacifist, there are circumstances in which I believe the use of force is appropriate — namely in the face of an enemy unconditionally bent on destroying me and my people." 

Science, War & Morality

Another highlight in Fine Books & Manuscripts is Einstein's response to Herbert Jehle's essay “For a Universal Morality,” which he submitted on Jehle's behalf to the Bulletin of Atomic Scientists.

Jehle was a student under Einstein in the late 1920s. He was a friend and acolyte of Dietrich Bonhoeffer, through whom he became an avowed pacifist. A German citizen, Jehle refused to participate in the armament of the Nazi regime, and was imprisoned at Gurs concentration camp. Upon his escape in 1941 he came to the United States, and reunited with Einstein at Princeton University in 1947.

Jehle's "For a Universal Morality" urged scientists to refuse to participate in war work under any circumstance or government – whether democratic or totalitarian. In the present letter, Einstein, with a profound respect, tries to convey to Jehle both the rightness of his position, and the difficulties it represents in the context of post-war world and personal politics.

While Einstein agreed wholeheartedly with Jehle's argument, he cautioned: "To an insane person, the truth appears foolish."

Herbert Jehle: A Fascinating Life

Dr. Herbert Jehle was a pioneering theoretical physicist whose work spans quantum field theory, biophysics, and astrophysics.

He first met Einstein as a student in Berlin in the late 1920s – and held on to his autographed notes from one of Einstein’s lectures – before receiving his doctorate from the Technische Hochschule Berlin in 1933. In the same year, Dietrich Bonhoeffer, Jehle's friend and mentor stepped down from his professorship at Berlin, in protest of the Nazi ascent to power, inspiring Jehle’s pacifist beliefs.

In 1940, when Jehle refused to assist in the German armament and atomic project, he was interned in Gurs concentration camp. He escaped in 1941 and made his way to the United States, eventually taking a position at Princeton University in 1947.

Remarkably, during his time at Princeton, Jehle provided a young Richard Feynman with the key paper by Dirac which unlocked his discovery of the path integral. As Feynman describes in his Nobel Prize acceptance speech, he met Jehle at a beer party at the Nassau Tavern in Princeton, where they began discussing Feynman's current work, and Jehle suggested he review Dirac’s paper which which brings the Lagrngian into quantum mechanics.

Jehle’s pacifist beliefs also provided inspiration to Einstein's own and they reconnected, bonding over shared views of social responsibility and ethics in science, and playing music together regularly, Einstein on violin, and Jehle on the piano.