Summary: The letter from Rudolf Carnap to Bertrand Russell expresses deep admiration for Russell's philosophical work and political activities, especially on his ninetieth birthday. Carnap acknowledges Russell's strong influence on his philosophical thinking and aligns with his fight for peace and negotiations instead of Cold War and bomb-testing. Despite his inclination towards theoretical pursuits, Carnap realizes the need to take a stand for survival in the current crisis. The letter reflects appreciation for Russell's encouragement, hope, and leadership in advocating for a better future, exemplifying the impact Russell has had across generations. Additionally, Russell's engagement in founding the Bertrand Russell Peace Foundation and Atlantic Peace Foundation reveals the challenges faced in fundraising and garnering support, highlighting the complexities of humanitarian efforts amidst political and social turmoil.