“Most people never run far enough on their first wind to find out they've got a second” 

“No fact in human nature is more characteristic than its willingness to live on a chance. The existence of the chance makes the difference… between a life of which the keynote is resignation and a life of which the keynote is hope.” 

“I fear to lose truth by the pretension to possess it already wholly.” 

“The aim of a college education is to teach you to know a good man when you see one.” 

“The union of the mathematician with the poet, fervor with measure, passion with correctness, this surely is the ideal.” 

“If merely 'feeling good' could decide, drunkenness would be the supremely valid human experience.” 

“A great nation is not saved by wars, it is saved by acts without external picturesqueness; by speaking, writing, voting reasonably; by smiting corruption swiftly; by good temper between parties; by the people knowing true men when they see them, and preferring them as leaders to rabid partisans and empty quacks.” 

“If you can change your mind, you can change your life.” 

“This life is worth living, we can say, since it is what we make it.” 

“we have to live today by what truth we can get today and be ready tomorrow to call it falsehood” 

“The strenuous life tastes better” 

“It is only by risking our persons from one hour to another that we live at all.” 

“If this life is not a real fight, in which something is eternally gained for the universe by success, it is no better than a game of private theatricals from which one may withdraw at will. But it feels like a real fight.” 

“These then are my last words to you. Be not afraid of life. Believe that life is worth living and your belief will help create the fact.” 

“The best use of life is to spend it for something that outlasts it.” 

To change one’s life: Start immediately. Do it flamboyantly.