“The pages of history are not written by those who watch from the sidelines, but by those who dare to turn the page, step forward, and shape the story with their own hands. To wait is to be forgotten, but to act is to be remembered.”

Preface
A Short History of Greek Mathematics (1884)

Source: Calculated Risk (1950), p. 7
Context: The story I would like to tell, I thought then, is the story of the men who lie here. Nothing can blur my memory of their tenacity and devotion to duty, of their refusal to be awed by seemingly insurmountable odds, by the swirling dust of the Salerno, by the treacherous mud of the Liri Valley,, or by the stinging snows of the high Apennines. Some chapters of their story I could not hope to tell. No one could tell them who was not there day after day in the foxholes that filled with water before they were half dug, and on the rocky peaks where not even a pack mule could gain a footing. But I can tell a part of the story. I can tell how and why the turn of the wheel of war took the men of the Fifth Army to Italy and what was behind the orders that sent them into battle at Salerno, on the Volturno, at Cassino, and on the flat and barren little strip of hell known as the Anzio beachhead; and I can give at least a glimpse of the bravery and sacrifices, not only of the Americans but of dozen other nationalities who fought their way into the not-so-soft underbelly of the Axis. They are men who paid heavily for their page in history. Testimony to their courage is the fact that they won 56 of the 255 Congressional Medals of Honor awarded to our Army during the entire war. I am proud to have had an opportunity to share in their calculated risk in the Mediterranean.

Inaugural Address (1989)
Context: I do not mistrust the future; I do not fear what is ahead. For our problems are large, but our heart is larger. Our challenges are great, but our will is greater. And if our flaws are endless, God's love is truly boundless.
Some see leadership as high drama, and the sound of trumpets calling, and sometimes it is that. But I see history as a book with many pages, and each day we fill a page with acts of hopefulness and meaning. The new breeze blows, a page turns, the story unfolds. And so today a chapter begins, a small and stately story of unity, diversity, and generosity — shared, and written, together.

Where Do We Go from Here : Chaos or Community? (1967), p. 109
1960s
Context: Many of the ugly pages of American history have been obscured and forgotten. A society is always eager to cover misdeeds with a cloak of forgetfulness, but no society can fully repress an ugly past when the ravages persist into the present. America owes a debt of justice which it has only begun to pay. If it loses the will to finish or slackens in its determination, history will recall its crimes and the country that would be great will lack the most indispensable element of greatness — justice.

As quoted in "The Gift of Books" in Biography Today : Profiles of People of Interest to Young Readers, Vol. 12, Issue 2 : Laura Bush by Joanne Mattern (2003), p. 17

Source: Mr. Magorium's Wonder Emporium

This evokes the famous statement by George Santayana in The Life of Reason Vol. 1 (1905): "Those who cannot remember the past are condemned to repeat it."
Vorkosigan Saga, The Vor Game (1990)

Source: Lexicon