“We propose first to expand credit in order to create demand. That new and greater demand must, of course, be met by a new and greater supply of goods, or all the evils of inflation and price rise will result. Here our Socialist planning must enter in. We must see that more goods are forthcoming to meet the new demand.”

1900s, The Strenuous Life: Essays and Addresses (1900), The Strenuous Life
Context: Let us, as we value our own self-respect, face the responsibilities with proper seriousness, courage, and high resolve. We must demand the highest order of integrity and ability in our public men who are to grapple with these new problems. We must hold to a rigid accountability those public servants who show unfaithfulness to the interests of the nation or inability to rise to the high level of the new demands upon our strength and our resources. Of course we must remember not to judge any public servant by any one act, and especially should we beware of attacking the men who are merely the occasions and not the causes of disaster.

Source: Success! (1977), p. 284; a portion of this — "In order to succeed we must first believe that we can" — has become widely attributed to Nikos Kazantzakis on the internet, but without citation of any sources.
Context: The American system demands success, and in order to succeed we must first believe that we can. Yet our society, with its intolerance of failure and poverty, traps millions of people in positions where any kind of success seems impossible to contemplate, and in which failure itself is a kind of passive rebellion against their own misery and the social system which created it in the first place.
To succeed it is necessary to accept the world as it is and rise above it.

1900s, The Strenuous Life: Essays and Addresses (1900), The Strenuous Life
Context: Let us, as we value our own self-respect, face the responsibilities with proper seriousness, courage, and high resolve. We must demand the highest order of integrity and ability in our public men who are to grapple with these new problems. We must hold to a rigid accountability those public servants who show unfaithfulness to the interests of the nation or inability to rise to the high level of the new demands upon our strength and our resources. Of course we must remember not to judge any public servant by any one act, and especially should we beware of attacking the men who are merely the occasions and not the causes of disaster.

The Philosophy of Hope https://www.marxists.org/archive/guyau/1895/hope.htm, Pages Choisies des Grands Écrivains" (1895).
Context: A child saw a butterfly poised on a blade of grass; the butterfly had been made numb by the north wind. The child plucked the blade of grass, and the living flower that was at its tip, still numb, remained attached. He returned home, holding his find in his hand. A ray of sunlight broke through, striking the butterfly’s wing, and suddenly, revived and light, the living flower flew away into the glare. All of us, scholars and workers, we are like the butterfly: our strength is made of a ray of light. Not even: of the hope of a ray. One must thus know how to hope; hope is what carries us higher and farther. “But it’s an illusion!” What do you know of this? Should we not take a step for fear that one day the earth will slide away from under our feet? Looking far into the past or the future is not the only thing; one must look into oneself. One must see there the living forces that demand to be expended, and we must act.

Book I, 1.140-[5]
History of the Peloponnesian War, Book I

Quoted in "Carrie Chapman Catt: A Public Life" by Jacqueline Van Voris (1996)

Source: My Years with General Motors, 1963, p. 387 (1964 edition)

Pavarotti : My World (1995)