What History's Greatest Minds Understood About Money, Time, and Compounding
Benjamin Franklin grew a fortune from beyond the grave. Isaac Newton — arguably the smartest man alive — lost his to a bubble. The difference was not intelligence.
Some of the sharpest minds in history left behind more than equations and inventions. They left behind a quiet, durable lesson about money — one that has almost nothing to do with being clever, and almost everything to do with time, patience, and temperament. The story is best told through three of them: a printer who turned a small bequest into a fortune two centuries after his death, a physicist who could weigh the planets but not resist a crowd, and a third whose name is attached to a famous line he almost certainly never said.
Benjamin Franklin's 200-year experiment
When Benjamin Franklin died in 1790, he attached a codicil to his will that was less a bequest than a controlled experiment in patience. He left £1,000 sterling — roughly 4,400 dollars at the time — to each of two cities he loved, Boston and Philadelphia. But he attached a condition that bordered on the mischievous: the money could not simply be spent.
Instead, it was to be lent out in small sums to young married tradesmen trying to start out in life, at five percent interest. The repayments, with their interest, would be lent again. For one hundred years the fund would do nothing but compound. After a century, each city could withdraw a portion for public works; the remainder would compound for a second hundred years before being fully distributed.
Franklin understood something most people never feel in their bones: that a modest sum, left alone and allowed to compound, becomes something else entirely given enough time. He even did the arithmetic in the codicil, projecting the fund would grow to over £130,000 within the first century.
The experiment ran its course. When the bequests finally matured around 1990 — two hundred years later — Boston's fund had grown to nearly five million dollars, and Philadelphia's to around two and a half million. The money built trade schools and funded scholarships. A printer who had been dead for two centuries was still putting young people to work, on nothing more than the principle that time does the heavy lifting if you let it.
A small sum, left alone and allowed to compound, becomes something else entirely. The variable that matters most is not the amount. It is the number of years.
Isaac Newton and the madness of crowds
If Franklin shows what patience builds, Isaac Newton shows what its absence destroys — and that raw intelligence is no protection at all.
In 1720, Britain was gripped by speculation in the shares of the South Sea Company. The price climbed week after week on little more than the promise of riches and the sight of neighbours getting rich. Newton, by then Master of the Royal Mint and one of the most celebrated minds in Europe, was an early investor. He bought in, watched the price rise, and sold — pocketing a healthy profit of several thousand pounds. Disciplined. Correct.
Then he watched the shares keep climbing without him. He watched people he considered his lesser get richer than he was. And he did what disciplined, intelligent people do when envy overtakes judgement: he bought back in, near the top, with far more money than before. When the bubble burst later that year, Newton lost a fortune — by most accounts around £20,000, a sum worth millions in today's money. He is said to have been so pained by the episode that he could not bear to hear the words "South Sea" spoken in his presence for the rest of his life.
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Take the IQ test →The famous line often attached to the story — "I can calculate the motion of the heavenly bodies, but not the madness of people" — is almost certainly apocryphal; there is no solid contemporary record of Newton saying it. But the loss itself is real and well documented, and the lesson survives the doubtful quote. The man who unlocked gravity was undone not by a lack of intelligence, but by impatience, comparison, and fear of missing out. Those are temperament problems, not IQ problems — and no amount of brilliance vaccinates you against them.
The quote Einstein never said
You have almost certainly seen it: "Compound interest is the eighth wonder of the world. He who understands it, earns it; he who doesn't, pays it." It is attributed, endlessly, to Albert Einstein.
There is no credible evidence Einstein ever said or wrote it. The line does not appear in his papers, letters, or recorded remarks, and researchers who have hunted for its origin find it surfacing only decades later, attached to his name to borrow his authority. It is a genuine piece of folk wisdom wearing a borrowed coat.
Which is fitting, in a way. The truth of the idea does not need Einstein. It needs only Franklin's two cities and Newton's ruined fortune to prove it. Compounding is real, it is patient, and it is indifferent to how clever you are. It rewards time in the market and punishes the very impulses — impatience, envy, panic — that intelligence alone cannot tame.
What the three geniuses agree on
Put their stories side by side and a single, unglamorous curriculum emerges:
- Time is the variable that matters most. Franklin's fortune came not from a large sum but from two hundred uninterrupted years. The earlier you begin, the less the amount matters.
- Ownership compounds; spending evaporates. Franklin's pounds were lent and reinvested, never consumed. The money worked because it was never spent.
- Temperament beats intelligence. Newton had the higher IQ and the worse outcome. The discipline to sit still, ignore the crowd, and resist fear is worth more than brilliance.
- Borrowed authority is not evidence. A truth does not become more true because a famous name is stapled to it. Test the idea, not the attribution.
None of this is a trading strategy. It is something more foundational — a way of thinking about money, time, and ownership that has to come before any tactic. The geniuses who got it right were not the cleverest. They were the most patient.
Further reading
If the foundation in this article resonates — time, ownership, and temperament over cleverness — it is precisely the ground covered, for complete beginners, in The Investor's Starter Kit: Mindset, Skill Set, Assets by Adir Trabelsi. It is a calm, jargon-free guide to the mental foundation behind everything above, written for people who were never taught how money really works. You can read more about the book here or find it on Amazon.
Frequently asked questions
Did Benjamin Franklin really leave money to compound for 200 years?
Yes. In a codicil to his 1790 will, Franklin left £1,000 each to Boston and Philadelphia, to be lent to young tradesmen at interest and allowed to compound for 100 years, then partially distributed, with the remainder compounding for a second century. By around 1990 the funds had grown to roughly five million dollars (Boston) and two and a half million (Philadelphia).
Did Isaac Newton lose money in the South Sea Bubble?
Yes. Newton invested in the South Sea Company in 1720, sold at a profit, then bought back in near the peak and lost around £20,000 when the bubble collapsed — a fortune by the standards of the day.
Did Newton really say "I can calculate the madness of people"?
Probably not. The quotation is widely repeated but has no solid contemporary source; it is best treated as apocryphal. Newton's financial loss, however, is well documented.
Did Einstein call compound interest the eighth wonder of the world?
There is no credible evidence that he did. The quotation appears only decades later and was attached to his name to lend it authority. The principle is sound; the attribution is not.
What is the real lesson about compounding?
That time, patience, and consistent ownership matter more than the size of the initial sum or the intelligence of the investor. Starting early and staying invested is what turns small amounts into large ones.
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Sources: Franklin's will and codicil; Wikipedia "Benjamin Franklin" and "South Sea Company"; Quote Investigator on the Einstein attribution. Image: Wikimedia Commons, public domain.