This is Roosevelt’s most famous proposal of his philosophy of “The Strenuous Life.” He believes in a manhood (and an extrapolated nation of men) defined by struggle, self-improvement, and responsibility. Almost as important as the formulation of these ideas are the way that Roosevelt designed and built himself around them, in terms of both physical and mental exertion. Silly as they may seem abstractly, the principles of the Strenuous Life take on an unavoidable concrete urgency coming from him.