“Knowledge has to be improved, challenged, and increased constantly, or it vanishes.”

Source: Out Of The Crisis (1982), p. 23 (Point 5 from the "Condensation of the 14 Points for Management" presented in Chapter 2)

Introductory : The Problem
Progress and Poverty (1879)
Context: It is true that wealth has been greatly increased, and that the average of comfort, leisure, and refinement has been raised; but these gains are not general. In them the lowest class do not share. I do not mean that the condition of the lowest class has nowhere nor in anything been improved; but that there is nowhere any improvement which can be credited to increased productive power. I mean that the tendency of what we call material progress is in nowise to improve the condition of the lowest class in the essentials of healthy, happy human life. Nay, more, that it is still further to depress the condition of the lowest class. The new forces, elevating in their nature though they be, do not act upon the social fabric from underneath, as was for a long time hoped and believed, but strike it at a point intermediate between top and bottom. It is as though an immense wedge were being forced, not underneath society, but through society. Those who are above the point of separation are elevated, but those who are below are crushed down.

On handling challenges - "TB Joshua Lambasts Money-Hungry Pastors, Politicians" http://vibeghana.com/2015/01/20/t-b-joshua-lambasts-money-hungry-pastors-politicians/ Vibe Ghana (January 20 2015)

Nobel Prize Autobiography, from Les Prix Nobel. The Nobel Prizes 1980, Editor Wilhelm Odelberg, (Nobel Foundation), Stockholm (1981).

Introductory
A Treatise on Man and the Development of His Faculties (1842)
Context: It is a remarkable fact in the history of science, that the more extended human knowledge has become, the more limited human power, in that respect, has constantly appeared. This globe, of which man imagines the haughty possessor, becomes, in the eyes of astronomer, merely a grain of dust floating in immensity of space: an earthquake, a tempest, an inundation, may destroy in an instant an entire people, or ruin the labours of twenty ages.... But if each step in the career of science thus gradually diminishes his importance, his pride has a compensation in the greater idea of his intellectual power, by which he has been enabled to perceive those laws which seem to be, by their nature, placed for ever beyond his grasp.

Letter to Lewis Campbell (9 November 1851) in Ch. 6 : Undergraduate Life At Cambridge October 1850 to January 1854 — ÆT. 19-22, p. 158
The Life of James Clerk Maxwell (1882)
Context: I believe, with the Westminster Divines and their predecessors ad Infinitum that "Man's chief end is to glorify God and to enjoy him for ever."
That for this end to every man has been given a progressively increasing power of communication with other creatures.
That with his powers his susceptibilities increase. That happiness is indissolubly connected with the full exercise of these powers in their intended direction. That Happiness and Misery must inevitably increase with increasing Power and Knowledge. That the translation from the one course to the other is essentially miraculous, while the progress is natural. But the subject is too high. I will not, however, stop short, but proceed to Intellectual Pursuits.

2015, Remarks to the Kenyan People (July 2015)
Context: Democracy is sometimes messy, and for leaders, sometimes it's frustrating. Democracy means that somebody is always complaining about something. Nobody is ever happy in a democracy about their government. If you make one person happy, somebody else is unhappy. Then sometimes somebody who you made happy, later on, now they’re not happy. They say, what have you done for me lately? But that's the nature of democracy. That's why it works, is because it's constantly challenging leaders to up their game and to do better.