1964 Memorial Edition, p. 266 http://www.jfklibrary.org/Research/Research-Aids/Ready-Reference/JFK-Quotations/Profiles-in-Courage-quotations.aspx 
Variant: A man does what he must — in spite of personal consequences, in spite of obstacles and dangers and pressures — and that is the basis of all human morality. 
Source: Pre-1960, Profiles in Courage (1956) 
Context: The courage of life is often a less dramatic spectacle than the courage of a final moment; but it is no less a magnificent mixture of triumph and tragedy. A man does what he must — in spite of personal consequences, in spite of obstacles and dangers, and pressures — and that is the basis of all human morality. In whatever area in life one may meet the challenges of courage, whatever may be the sacrifices he faces if he follows his conscience — the loss of his friends, his fortune, his contentment, even the esteem of his fellow men — each man must decide for himself the course he will follow. The stories of past courage can define that ingredient — they can teach, they can offer hope, they can provide inspiration. But they cannot supply courage itself. For this each man must look into his own soul. 
Context: For without belittling the courage with which men have died, we should not forget those acts of courage with which men — such as the subjects of this book — have lived. The courage of life is often a less dramatic spectacle than the courage of a final moment; but it is no less a magnificent mixture of triumph and tragedy. A man does what he must — in spite of personal consequences, in spite of obstacles and dangers, and pressures — and that is the basis of all human morality. In whatever area in life one may meet the challenges of courage, whatever may be the sacrifices he faces if he follows his conscience — the loss of his friends, his fortune, his contentment, even the esteem of his fellow men — each man must decide for himself the course he will follow. The stories of past courage can define that ingredient — they can teach, they can offer hope, they can provide inspiration. But they cannot supply courage itself. For this each man must look into his own soul.
                                    
“In spite of all the obstacles that Teilhard perhaps wisely puts in our way, it is possible to discern a train of thought in The Phenomenon of Man.”
1960s, Review of Teilhard de Chardin's "The Phenomenon of Man", 1961
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Peter Medawar 40
scientist 1915–1987Related quotes
“They no doubt clearly discern all our words and actions, if not all our thoughts too”
                                        
                                        Letter to Mary Bishop, an important Methodist "Class Meeting" leader,  https://books.google.com/books?id=E-iMVOU6PhYC&pg=PA33&lpg=PA33&dq=%22one+of+his+leading+women+class+leaders,%22&source=bl&ots=TjalEPj1rz&sig=MGwiThaIzWLfs6AWUzta-aZNBUk&hl=en&sa=X&ved=0ahUKEwiX3oyws6_TAhVHRyYKHbRvCv8Q6AEIJDAA#v=onepage&q=%22one%20of%20his%20leading%20women%20class%20leaders%2C%22&f=false  (12 June 1773), in The works of the Rev. John Wesley, Seven Volumes, (1853),  Carlton & Phillips, New York, vol. VII, p. 164.  https://books.google.com/books?id=P4QsAQAAMAAJ&pg=PA164&dq=It+has+in+all+ages+been+allowed+that+the+communion+of+saints+extends+to+those+in+paradise&hl=en&sa=X&ved=0ahUKEwjejuPcrq_TAhWG0iYKHefIDYwQ6AEIJDAA#v=onepage&q=It%20has%20in%20all%20ages%20been%20allowed%20that%20the%20communion%20of%20saints%20extends%20to%20those%20in%20paradise&f=false 
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Context: It has in all ages been allowed that the communion of saints extends to those in paradise as well as those upon earth as they are all one body united under one Head. And "Can death’s interposing tide / Spirits one in Christ divide?" But it is difficult to say either what kind or what degree of union may be between them. It is not improbable their fellowship with us is far more sensible than ours with them. Suppose any of them are present, they are hid from our eyes, but we are not hid from their sight. They no doubt clearly discern all our words and actions, if not all our thoughts too; for it is hard to think these walls of flesh and blood can intercept the view of an angelic being. But we have in general only a faint and indistinct perception of their presence, unless in some peculiar instances, where it may answer some gracious ends of Divine Providence. Then it may please God to permit that they should be perceptible, either by some of our outward senses or by an internal sense for which human language has not any name. But I suppose this is not a common blessing. I have known but few instances of it. To keep up constant and close communion with God is the most likely means to obtain this also.
                                    
“Suffering is part of our training program for becoming wise.”
                                        
                                        As quoted in TIME magazine (6 October 1952) 
1950s