“That life is long which answers life's great end.”

1960s, Keep Moving From This Mountain (1965)
Context: Each of us lives in two realms, the "within" and the "without." The within of our lives is somehow found in the realm of ends, the without in the realm of means. The within of our [lives], the bottom — that realm of spiritual ends expressed in art, literature, morals, and religion for which at best we live. The without of our lives is that realm of instrumentalities, techniques, mechanisms by which we live. Now the great temptation of life and the great tragedy of life is that so often we allow the without of our lives to absorb the within of our lives. The great tragedy of life is that too often we allow the means by which we live to outdistance the ends for which we live.

"Technical Education" (1877)
1870s

Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 328.

The Use of Life (1894), ch. VI: National Education
Source: The Use of Life http://archive.org/details/uselife02lubbgoog/page/n114/mode/2up on Archive.Org, pages 102—103

Source: Address on Laying the Cornerstone of the Bunker Hill Monument (1825), p. 71
Context: Mind is the great lever of all things; human thought is the process by which human ends are ultimately answered; and the diffusion of knowledge, so astonishing in the last half-century, has rendered innumerable minds, variously gifted by nature, competent to be competitors or fellow-workers on the theatre of intellectual operation.

Breaking Strain, p. 172
2000s and posthumous publications, The Collected Stories of Arthur C. Clarke (2001)

Source: Good to Great: Why Some Companies Make the Leap... and Others Don't