“We are only seeking Man. We have no need of other worlds. We need mirrors. We don't know what to do with other worlds. A single world, our own, suffices us; but we can't accept it for what it is. We are searching for an ideal image of our own world: we go in quest of a planet, of a civilisation superior to our own but developed on the basis of a prototype of our primeval past. At the same time, there is something inside us which we don't like to face up to, from which we try to protect ourselves, but which nevertheless remains, since we don't leave Earth in a state of primal innocence. We arrive here as we are in reality, and when the page is turned and that reality is revealed to us — that part of our reality which we would prefer to pass over in silence — then we don't like it any more.”

Source: Solaris (1961), Ch. 6: "The Little Apocrypha", p. 72
Context: We are only seeking Man. We have no need of other worlds. We need mirrors. We don't know what to do with other worlds. A single world, our own, suffices us; but we can't accept it for what it is. We are seaching for an ideal image of our own world: we go in quest of a planet, of a civilisation superior to our own but developed on the basis of a prototype of our primeval past. At the same time, there is something inside us which we don't like to face up to, from which we try to protect ourselves, but which nevertheless remains, since we don't leave Earth in a state of primal innocence. We arrive here as we are in reality, and when the page is turned and that reality is revealed to us — that part of our reality which we would prefer to pass over in silence — then we don't like it any more.

Source: Aphorisms and Reflections (1901), p. 31

My New Gender Workbook: A Step-by-step Guide to Achieving World Peace Through Gender Anarchy and Sex Positivity (2013), p. 6

Interview with Evelyn Rich (March 1985)

Ill Fares the Land (2010), Ch. 2 : The World We Have Lost

Paraphrased variant: We do not need magic to change the world, we carry all the power we need inside ourselves already: we have the power to imagine better.
Harvard address (2008)

1920s, Toleration and Liberalism (1925)
Context: It is for these reasons that it seems clear that the results of the war will be lost and we shall only be entering a period of preparation for another conflict unless we can demobilize the racial antagonisms, fears, hatreds, and suspicions, and create an attitude of toleration in the public mind of the peoples of the earth. If our country is to have any position of leadership, I trust it may be in that direction, and I believe that the place where it should begin is at home. Let us cast off our hatreds. Let us candidly accept our treaties and our natural obligations of peace. We know and everyone knows that these old systems, antagonisms, and reliance on force have failed. If the world has made any progress, it has been the result of the development of other ideals. If we are to maintain and perfect our own civilization, if we are to be of any benefit to the rest of mankind, we must turn aside from the thoughts of destruction and cultivate the thoughts of construction. We can not place our main reliance upon material forces. We must reaffirm and reinforce our ancient faith in truth and justice, in charitableness and tolerance. We must make our supreme commitment to the everlasting spiritual forces of life. We must mobilize the conscience of mankind.

Source: Think Big: Unleashing Your Potential for Excellence