You must not change one thing, one pebble, one grain of sand, until you know what good and evil will follow on that act. The world is in balance, in Equilibrium. A wizard’s power of Changing and Summoning can shake the balance of the world. It is dangerous, that power. It is most perilous. It must follow knowledge, and serve need. To light a candle is to cast a shadow.
– A Wizard of Earthsea (1968)

If we must all agree, all work together, we’re no better than a machine. If an individual can’t work in solidarity with his fellows, it’s his duty to work alone. His duty and his right. We have been denying people that right. We’ve been saying, more and more often, you must work with the others, you must accept the rule of the majority. But any rule is tyranny. The duty of the individual is to accept no rule, to be the initiator of his own acts, to be responsible. Only if he does so will the society live, and change, and adapt, and survive. We are not subjects of a State founded upon law, but members of a society founded upon revolution. Revolution is our obligation: our hope of evolution.
– The Dispossessed (1974)

Sometimes one’s very angry and preaches, but I know that to clinch a point is to close it. To leave the reader free to decide what your work means, that’s the real art; it makes the work inexhaustible.
– “The Magician” by Maya Jaggi in The Guardian (17 December 2005)

No truth can make another truth untrue.
All knowledge is part of the whole knowledge.
Once you have seen the larger pattern,
You cannot get back to seeing the part as the whole.
– Four Ways to Forgiveness (1996)

I have never found anywhere, in the domain of art, that you don’t have to walk to. (There is quite an array of jets, buses and hacks which you can ride to Success; but that is a different destination.) It is a pretty wild country. There are, of course, roads. Great artists make the roads; good teachers and good companions can point them out. But there ain’t no free rides, baby. No hitchhiking. And if you want to strike out in any new direction — you go alone. With a machete in your hand and the fear of God in your heart.
– The Language of the Night (1979)

To be an atheist is to maintain God. His existence or his nonexistence, it amounts to much the same, on the plane of proof. Thus proof is a word not often used among the Handdarata, who have chosen not to treat God as a fact, subject either to proof or to belief: and they have broken the circle, and go free.
To learn which questions are unanswerable, and not to answer them: this skill is most needful in times of stress and darkness.

Light is the left hand of darkness
and darkness the right hand of light.
Two are one, life and death, lying
together like lovers in kemmer,
like hands joined together,
like the end and the way.
– The Left Hand of Darkness (1969)

Things don’t have purposes, as if the universe were a machine, where every part has a useful function. What’s the function of a galaxy? I don’t know if our life has a purpose and I don’t see that it matters. What does matter is that we’re a part. Like a thread in a cloth or a grass-blade in a field. It is and we are. What we do is like wind blowing on the grass.

The end justifies the means. But what if there never is an end? All we have is means.
– The Lathe of Heaven (1971)

The Revolution is in the individual spirit, or it is nowhere. It is for all, or it is nothing. If it is seen as having any end, it will never truly begin. We can’t stop here. We must go on. We must take the risks.
– The Dispossessed (1974)

True myth may serve for thousands of years as an inexhaustible source of intellectual speculation, religious joy, ethical inquiry, and artistic renewal. The real mystery is not destroyed by reason. The fake one is. You look at it and it vanishes. You look at the Blond Hero — really look — and he turns into a gerbil. But you look at Apollo, and he looks back at you. The poet Rilke looked at a statue of Apollo about fifty years ago, and Apollo spoke to him. “You must change your life,” he said. When true myth rises into consciousness, that is always its message. You must change your life. 
– “Myth and Archetype in Science Fiction” (1976)

http://en.wikiquote.org/wiki/Ursula_K._Le_Guin

http://en.wikiquote.org/wiki/The_Dispossessed