“Courage… is not a selfish attribute: it is only possible if you are pursuing a wider and more worthy goal.”

This quotation was actually by Henning W. Prentis, Jr., president of the Armstrong Cork Company and former president of the National Association of Manufacturers, in a February 1943 address entitled " The Cult of Competency http://ergo-sum.net/literature/CultOfCompetency.pdf" delivered at a Mid-Year Convocation of the General Alumni Society of the University of Pennsylvania (The General Magazine and Historical Chronicle, Vol. XLV, Numb. III, April 1943, pp. 272-73).
This quotation sometimes appears joined with the above one, most notably as part of a longer piece which began circulating on the Internet shortly after the 2000 U.S. Presidential Election ( "The Fall of the Athenian Republic," http://www.snopes.com/politics/quotes/tyler.asp Urban Legends Reference Pages):
::A democracy is always temporary in nature; it simply cannot exist as a permanent form of government. A democracy will continue to exist up until the time that voters discover that they can vote themselves generous gifts from the public treasury. From that moment on, the majority always votes for the candidates who promise the most benefits from the public treasury, with the result that every democracy will finally collapse due to loose fiscal policy, which is always followed by a dictatorship.
The average age of the world's greatest civilizations from the beginning of history has been about 200 years. During those 200 years, these nations always progressed through the following sequence:
::* From bondage to spiritual faith;
::* From spiritual faith to great courage;
::* From courage to liberty;
::* From liberty to abundance;
::* From abundance to complacency;
::* From complacency to apathy;
::* From apathy to dependence;
::* From dependence back into bondage.
Attributed

Markings (1964)

A Study of History (1934–1961)

Speech to Young America's Foundation at Reagan Ranch https://www.youtube.com/watch?v=cZRuwjvAMuQ,
2015

Too Busy Not to Pray (2008, InterVarsity Press)

Kunnumpuram, Kurien, 2011 “Theological Exploration,” Jnanadeepa: Pune Journal of Religious Studies 14/2 (July-Dec 2011)
On God

Source: Doing Virtuous Business (Thomas Nelson, 2011), p. 3.