Andrew Carnegie devoted the later part of his life to promoting world peace. He argued that just as men had realized the barbarity of dueling ("private war") they would soon evolve away from the "hell" that is national war.
"What is wrong for the individual cannot be right for the nation."
The excerpt attached on the right sidebar is a great primary source for students to understand one of the world's greatest businessmen's thinking behind world peace. Although his dream has yet to be achieved, this excerpt is interesting for its application of the evolution of humanity (Carnegie once said his motto was "All is well since all grows better") and for the optimism expressed so close to the beginning of WWI.
For the full short letter, please click here.