Although he possesses an extraordinary intellect, Robert Stadler holds a mistaken premise regarding the mind's proper role in human life. Stadler is a brilliant theoretical physicist, but he has contempt for the practical affairs of living. He believes that the mind is effective only when dealing with questions of pure science — issues of abstract speculation — such as the research on the nature of cosmic rays that established his reputation. All questions of practical application involve a human element, and Stadler thinks that men are fundamentally irrational. Stadler believes that most humans are driven by impulses and desires, not by the mind. His belief about the nature of humanity is the reason why Stadler was instrumental in founding the State Science Institute. He assumes that people won't voluntarily support science and the mind; therefore, the government must dictate such support. In his view, the ignorant public desires nothing but clever "gadgets" from science — inventions to improve their quality of life. He despises that the public has no regard for the higher concerns of "pure science." He expresses to Dagny his scornful bewilderment that a genius capable of solving the monumental problems of theoretical physics would waste his brains on such a practical device as a motor.
Dagny's response, however, comes from opposite premises. She knows that the motor's inventor applied his mind to the project "because he liked living on this earth." Dagny rejects the premise that reason is valid only when grappling with a "higher" realm of ideas. She understands that creating prosperity on earth is vital. She knows the role intellect played in Rearden's creation of his metal, in her own achievement of building the John Galt Line, and in the inventor's construction of the motor. She recognizes that, although people may often behave irrationally, their survival depends on embracing their rational nature. In time, the public will recognize facts and understand the truth, just as it has come to see the merits of Rearden Metal and the John Galt Line. Humans must be free to use their own minds. Dagny's estimate of man's nature is significantly different than Dr. Stadler's. He believes that mankind is composed predominantly of irrational brutes, but she knows that man is a rational animal.
