'No army can withstand the strength of an idea whose time has come.'

'We are on the move now ... Like an idea whose time has come, not even the marching of mighty armies can halt us. We are moving to the land of freedom ...'

- Martin Luther King Jr. at the conclusion of the five-day, 54-mile march

'Keep working on a plan. Make no little plans. Make the biggest one you can think of, and spend the rest of your life carrying it out.'

- President Harry Truman (1884-1972)

A quote by Howard Hughes

"Do the impossible, because almost everyone has told me my ideas are merely fantasies."

'Hearts are the strongest when they beat in response to noble ideals.'

- American diplomat Ralph Bunche (1904–1971)

'An idea is salvation by imagination.'

- US architect Frank Lloyd Wright

'How wonderful it is that nobody need wait a single moment before starting to improve the world.' - Anne Frank

'All that is gold does not glitter, not all those who wander are lost; the old that is strong does not wither, deep roots are not reached by the frost.'

- "The Lord of the Rings" author JRR Tolkien (1892-1973)

'If the time is not ripe, we have to ripen the time.'

- Activist Dorothy Height (1912-2010)

'Only those who dare to fail greatly can ever achieve greatly.'

- Bobby Kennedy

'Many of life's failures are people who did not realize how close they were to success when they gave up.'

- Inventor Thomas Edison (1847 - 1931)

'Organize, agitate, educate, must be our war cry.'

- Suffragist Susan B. Anthony (1820-1906)

'If you hear a voice within you say 'you cannot paint,' then by all means paint, and that voice will be silenced.'

- Vincent van Gogh (1853-1890)

A quote by Ralph Bunche

"The well-being and the hopes of the peoples of the world can never be served until peace - as well as freedom, honor and self-respect - is secure."

'No one is useless in this world who lightens the burdens of another.'

-Charles Dickens (1812-1870), in "Our Mutual Friend"

'Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world.'

- Albert Einstein

'I have not failed. I've just found 10,000 ways that won't work.'

-Inventor and businessman Thomas Edison (1847-1931)

'One man can make a difference and every man should try.'

- Jacqueline Kennedy Onassis (1929-1994)

'Few will have the greatness to bend history itself, but each of us can work to change a small portion of events, and in the total of all those acts will be written the history of this generation.'

- Senator Robert F. Kennedy (1925–1968)

'Real courage is when you know you're licked before you begin, but you begin anyway and see it through no matter what.'

- Harper Lee from "To Kill a Mockingbird"

The long-tail influence of Thoreau's 'Civil Disobedience'

His essay "Civil Disobedience" laid out both a practical and a moral plan for resisting unjust governments, inspiring civil rights leaders like Mahatma Gandhi and Martin Luther King Jr., as well as anti-war anarchists like Emma Goldman and literary figures like Leo Tolstoy.

'No big challenge has ever been solved, and no lasting improvement has ever been achieved, unless people dare to try something different.'

- Apple CEO Tim Cook (1960 - present)

'Not everything that is faced can be changed, but nothing can be changed until it is faced.'

- Author James Baldwin (1924–1987)

'Every day sees humanity more victorious in the struggle with space and time.'

- Radio inventor Guglielmo Marconi

'Knowledge will forever govern ignorance.'

- US President James Madison (1751-1836)

A quote by Florence Nightingale

"Poetry and imagination begin life."

A quote by scientist Nikola Tesla

"The scientific man does not aim at an immediate result ... His duty is to lay the foundation for those who are to come, and point the way."

'The man who can drive himself further once the effort gets painful is the man who will win.'

- Roger Bannister (1929-2018)

'I think a hero is an ordinary individual who finds the strength to persevere and endure in spite of overwhelming obstacles.'

- "Superman" actor Christopher Reeve (1952 - 2004)

A quote by Herman Melville

"Whoever is not in the possession of leisure can hardly be said to possess independence."

'Hope is the thing with feathers that perches in the soul—and sings the tunes without the words—and never stops at all.'

- Emily Dickinson (1830-1886)

'Happiness depends more upon the internal frame of a persons own mind—than on the externals in the world.'

- George Washington (1732-1799)

'A word after a word after a word is power.'

- Author Margaret Atwood (1939-present)

Before Dawkins, other biologists proposed the power of mutating ideas

Nobel Prize winner Jacques Monod proposed, “Ideas have retained some of the properties of organisms. Like them, they tend to perpetuate their structure and to breed; they too can fuse, recombine, segregate their content; indeed they too can evolve, and in this evolution selection must surely play an important role.”

Writer Christopher Hitchens on why Orwell matters

In this 2008 segment with NPR, the author of "Why Orwell Matters" discusses his admiration for the author and fields questions from callers. Hitchens notes that anyone can write about tyranny, but that Orwell's brilliance is in exploring why people "are so keen to obey."

Who said 'rebellion to tyrants is obedience to God'?

As a brief, punchy statement rejecting unjust authority, "Rebellion to tyrants is obedience to God" became widely adopted during the American Revolution. The phrase is often misattributed to Benjamin Franklin and Thomas Jefferson, the latter of whom used it on his personal seal. This fact-checked article dives into the history of the phrase, claiming it was first used in 1770 in an epitaph for an English judge. Read more here.

'One child, one teacher, one book, one pen can change the world'

- Activist and author Malala Yousafzai (1997-present)

'Men and nature must work hand in hand. The throwing out of balance of the resources of nature throws out of balance also the lives of men.'

- President Franklin D. Roosevelt (1882–1945)

'I would rather that my spark should burn out in a brilliant blaze than it should be stifled by dry-rot ... The proper function of man is to live, not to exist. I shall not waste my days in trying to prolong them. I shall use my time.'

- Author Jack London (1876 - 1916)

'No one has ever become poor by giving.'

- Anne Frank (1929-1945)

'When you're climbing Mount Everest, nothing is easy. You just take one step at a time, never look back and always keep your eyes glued to the top.'

- Author Jacqueline Susann (1918-1974)

'In three words I can sum up everything I've learned about life: it goes on.'

-Poet Robert Frost (1874-1963)

'Keep Calm and Carry On' was long-forgotten World War II propaganda

The British Ministry of Information developed the stoic phrase ahead of German attacks at the start of World War II in 1939. It was never officially released on posters and then lay dormant until 2000, when one of the remaining posters was discovered at a bookstore in the UK. It has since been adapted into countless memes.

A quote by award-winning actor Tom Hanks

"We are still in the position of waking up and having a choice. Do I make the world better today somehow, or do I not bother?"

'It's the repetition of affirmations that leads to belief. And once that belief becomes a deep conviction, things begin to happen.'

- Legendary boxer Muhammad Ali (1942–2016)

'Be silent, if you choose; but when it is necessary, speak—and speak in such a way that people will remember it.'

- Wolfgang Amadeus Mozart (1756–1791)

'Others have seen what is and asked why. I have seen what could be and asked why not.'

- Pablo Picasso

The American Revolution became a template for a colonized world

The robust and radical transformation during the American Revolution created a template for dozens of future independence movements. Its key ideas of republicanism, individualism, and equality inspired revolutions in France, Haiti, Ireland, and more, paving the way for the broadly democratic world we know today.

'I may not have gone where I intended to go, but I think I have ended up where I needed to be.'

- Author Douglas Adams (1952-2001)

Washington's military acumen and political judgment were crucial to the Continental Army's success

In this podcast, Pulitzer Prize-winning historian Rick Atkinson argues that Washington's endurance, strategic communication, political judgment, and ability to elevate capable subordinates proved decisive, in sharp contrast to the failures of British leadership during the war.

A quote by Whitney Houston

"I believe that children are our future. Teach them well and let them lead the way. Show them all the beauty they possess inside."