“We are obliged to hear all that witnesses have to say; but it is a canticle of Courts of justice that witnesses non numerentur sed ponderentur: they are not to be numbered but weighed. It is the nature of the human mind, it is the perfection of the human heart, to serve a friend in distress; but in doing so, a man should not transgress the higher calls of religion and morality, the obligations of an oath. We are not monks and recluses, as was said in another place,1 but come from a class in society that I hope and believe gives us opportunities of seeing as much of the world, and that has as much virtue amongst its members as any other, however elevated.”

"Saving the Rabbit from the Fox", p. 247
Morals, Reason, and Animals (1987)

Blackburn, Low & Co. v. Vigors (1887), L. R. 12 Ap. Ca. 543.

Attributed in posthumous publications, Einstein and Religion (1999)
Context: It seems to me that the idea of a personal God is an anthropomorphic concept which I cannot take seriously. I feel also not able to imagine some will or goal outside the human sphere. My views are near to those of Spinoza: admiration for the beauty of and belief in the logical simplicity of the order and harmony which we can grasp humbly and only imperfectly. I believe that we have to content ourselves with our imperfect knowledge and understanding and treat values and moral obligations as a purely human problem—the most important of all human problems.

From a letter to Murray W. Gross (26 April 1947), p. 138

Draft for a Statement of Human Obligation (1943)
Context: There is a reality outside the world, that is to say, outside space and time, outside man's mental universe, outside any sphere whatsoever that is accessible to human faculties.
Corresponding to this reality, at the centre of the human heart, is the longing for an absolute good, a longing which is always there and is never appeased by any object in this world.
Another terrestrial manifestation of this reality lies in the absurd and insoluble contradictions which are always the terminus of human thought when it moves exclusively in this world.
Just as the reality of this world is the sole foundation of facts, so that other reality is the sole foundation of good.
That reality is the unique source of all the good that can exist in this world: that is to say, all beauty, all truth, all justice, all legitimacy, all order, and all human behaviour that is mindful of obligations.
Those minds whose attention and love are turned towards that reality are the sole intermediary through which good can descend from there and come among men.
Although it is beyond the reach of any human faculties, man has the power of turning his attention and love towards it.
Nothing can ever justify the assumption that any man, whoever he may be, has been deprived of this power.
It is a power which is only real in this world in so far as it is exercised. The sole condition for exercising it is consent.
This act of consent may be expressed, or it may not be, even tacitly; it may not be clearly conscious, although it has really taken place in the soul. Very often it is verbally expressed although it has not in fact taken place. But whether expressed or not, the one condition suffices: that it shall in fact have taken place.
To anyone who does actually consent to directing his attention and love beyond the world, towards the reality that exists outside the reach of all human faculties, it is given to succeed in doing so. In that case, sooner or later, there descends upon him a part of the good, which shines through him upon all that surrounds him.

No Compromise – No Political Trading (1899)

Italian Report (1955)
Context: A more rewarding approach to painting, in my opinion the only valid one, is to regard it as a deeply personal and private activity and to remember that even when the painter works directly for the public — when there is sufficient common ground to allow him to do so — the real merit of the work will depend on the personal vision of the artist and the work will only be truly understood if it is approached by each in the same spirit as the painter painted it. We must be willing to assume the same sort of responsibility and share the dilemma out of which the work was created in order to be able to feel with the artist. Since the deepest and truest dilemma, from which all good art springs, is the human condition we have every right to regard the needs of our own consciousness as the final court in judging the merit of a work of art, we have in fact a moral obligation to do so. This demands the precise honesty from the spectator as was required from the artist in making the painting. It is their common ground, the area within which communication can occur. Art in the end speaks to the secret soul of the individual and of the most secret sorrows. For this reason it is true that the development that produces great art is a moral and not an aesthetic development..

2009, Nobel Prize acceptance speech (December 2009)
Context: We do not have to think that human nature is perfect for us to still believe that the human condition can be perfected. We do not have to live in an idealized world to still reach for those ideals that will make it a better place. The non-violence practiced by men like Gandhi and King may not have been practical or possible in every circumstance, but the love that they preached — their fundamental faith in human progress — that must always be the North Star that guides us on our journey.
For if we lose that faith — if we dismiss it as silly or naïve; if we divorce it from the decisions that we make on issues of war and peace — then we lose what's best about humanity. We lose our sense of possibility. We lose our moral compass.
Like generations have before us, we must reject that future. As Dr. King said at this occasion so many years ago, "I refuse to accept despair as the final response to the ambiguities of history. I refuse to accept the idea that the 'isness' of man's present condition makes him morally incapable of reaching up for the eternal 'oughtness' that forever confronts him."
Let us reach for the world that ought to be — that spark of the divine that still stirs within each of our souls.

Defying the Tomb: Selected Prison Writings and Art of Kevin Rashid Johnson (2010)

Opening lines, p. 104
Variant translations:
What is God-given is called nature; to follow nature is called Tao (the Way); to cultivate the Way is called culture.
As translated by Lin Yutang in The Importance of Living (1937), p. 143
What is God-given is called human nature.
To fulfill that nature is called the moral law (Tao).
The cultivation of the moral law is called culture.
As translated by Lin Yutang in From Pagan to Christian (1959), p. 85
The Doctrine of the Mean