In his famous speech exhorting Americans to support funding for space research, and specifically the goal of sending astronauts to the moon, President Kennedy made excellent use of all three types of persuasion described by Aristotle.
Ethos is an appeal that is based on the authority and credibility of the speaker. The US president by definition carries authority when he speaks personally, which is why Kennedy delivered this message himself. Kennedy further bolstered his credibility by choosing to deliver the speech at Rice University. Not only did he tacitly borrow the university’s excellent academic reputation by being there, but Rice also named him an honorary visiting professor, something the president mentioned immediately before beginning his remarks.
Pathos is an appeal to the emotions of the listener, which in this case is an appeal to the audience’s patriotism and national pride. Kennedy referenced America’s history as a nation of ambitious strivers who overcame great hardships, presenting the space initiative as a worthy challenge:
We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.
Kennedy also emphasized the patriotic importance of beating the Soviet Union in a competition where they had a head start. America would not see the moon “governed by a hostile flag of conquest, but by a banner of freedom and peace,” Kennedy said. “We have vowed that we shall not see space filled with weapons of mass destruction, but with instruments of knowledge and understanding.”
Not allowing the Russians to beat America in the space race, and potentially gain a military advantage, is simultaneously part of Kennedy’s appeal to logos, or logic.
Kennedy made a detailed case that the US had the technological infrastructure and intellectual expertise to accomplish the mission and that the cost was not an insurmountable one. He broke it down to fifty cents per week for every American, making it understandable to everyone. The president also argued that investing in space research would bring great economic returns in the form of new industries, new technologies, and new jobs:
The growth of our science and education will be enriched by new knowledge of our universe and environment, by new techniques of learning and mapping and observation, by new tools and computers for industry, medicine, the home as well as the school,” Kennedy said. “Space and related industries are generating new demands in investment and skilled personnel, and this city and this State, and this region, will share greatly in this growth.