“The fundamental maxim of those who stand at the head of this Age, and therefore the principle of the Age, is this,—to accept nothing as really existing or obligatory, but that which they can understand and clearly comprehend.”

Vol. I, ch. 1
History of England (1849–1861)

Heinrich Rohrer explaining how progress in miniaturization implies developing techniques in self-assembling molecular structures, in his Nishina Memorial Lecture at the University of Tokyo, on June 25, 1993. Published in [Nishina memorial lectures: creators of modern physics, Springer, 2008, 506, 4431770550]

The Confessions of a Lost Dog (London: Griffith & Farran, 1867), p. 19.

Source: The Legacy of Muslim Rule in India (1992)

Source: The Wealth of Nations (1776), Book III, Chapter IV, p. 448.

Thoughts on Man's Purpose in Life (1974)
Context: I do not claim to have a magic answer. But I believe there are some basic principles of existence, propounded by thinkers through the ages, which can guide us toward the goal of finding a purpose in life.
Among these principles of existence, responsibility is the one which forces man to become involved. Acceptance of responsibility means that the individual takes upon himself an obligation. Responsibility is broad and continuous. None of us are ever free of it, even if our work is unsuccessful.
Responsibility implies a commitment to self which many are not willing to make; they are strongly attracted to accepting a course of action or direction for their lives imposed by an external source. Such a relationship absolves the individual from the personal decision-making process. He wraps himself in the security blanket of inevitability or dogma, and need not invest the enormous amounts of time, effort and, above all, the thought required to make creative decisions and meaningfully participate in the governance of his life.
Responsibility also implies a commitment to others, or as Confucius taught, each of us is meant to rescue the world. It is the business of little minds to shrink from this task or to go about it without enthusiasm. Neither art, nor science, nor any of the great works of humanity would ever come into being without enthusiasm.
The sense of responsibility for doing a job right seems to be declining. In fact, the phrase "I am not responsible" has become a standard response in our society to complaints on a job poorly done. This response is a semantic error. Generally what person means is: "I cannot be held legally liable." Yet, from a moral or ethical point of view, the person who disclaims responsibility is correct: by taking this way out he is truly not responsible; he is irresponsible.

Letter http://books.google.com/books?id=MyfeAwAAQBAJ&amp;q=%22No+democracy+can+long+survive+which+does+not+accept+as+fundamental+to+its+very+existence+the+recognition+of+the+rights+of+its+minorities%22&amp;pg=PA401#v=onepage to Walter Francis White, president of the NAACP (25 June 1938) <br class="br">1930s

Rule of St. Benedict: Chapter 30: How Boys Are to Be Corrected

Summa Contra Gentiles II, 18.2 (see also Summa Theologica I, q. 45, art. 3 ad 2)