Darwin's Pros-and-Cons List: Making a Big Decision

Act one · the room

You are standing at his elbow

He has just come back from Scotland, where he spent days at Glen Roy puzzling over the strange terraces on the hillsides. On 15 July he opened two new notebooks: D, on how species change, and M, on minds, habits and moods. He is twenty-nine, and he is filling both.

But this morning he is not doing science. He takes a sheet, sharpens a pencil and writes four words at the top: This is the Question. Then he draws a circle round them, as if to keep them from escaping.

Down the middle goes a line. On the left he writes Marry; on the right, Not Marry. It is all in pencil — what you use when you are not yet sure you want to have written it.

Sixty-six years earlier, Benjamin Franklin had described the same method in a letter to a friend stuck over a job offer. He called it "Moral or Prudential Algebra." Darwin never mentions Franklin; he may simply have reinvented it, as most of us do.

Act two · the real sheet

The page itself

This is Darwin's actual sheet, kept at Cambridge University Library as DAR 210.8.2. Hover over or tap any line to see what scholars know about it: what was squeezed in later, what he crossed out. His spelling and dashes are left as he wrote them.

This is the Question

Marry

Children — (if it Please God) —Children — (if it please God) —

Constant companion, (& friend in old age) who will feel interested in one, — object to be beloved & played with. — — better than a dog anyhow. —A constant companion (and a friend in old age) who will take an interest in you — something to love and to play with — better than a dog anyhow.

Home, & someone to take care of house — Charms of music & female chit-chat. — These things good for one's health. — but terrible loss of time. —A home, and someone to look after it — music, and conversation — good for one's health — but a terrible loss of time.

My God, it is intolerable to think of spending ones whole life, like a neuter bee, working, working, & nothing after all. — No, no won't do. —My God — to spend a whole life like a worker bee, working, working, and nothing at the end of it. No. That won't do.

Only picture to yourself a nice soft wife on a sofa with good fire, & books & music perhaps — Compare this vision with the dingy reality of Grt. Marlbro' St.Picture a wife on a sofa, a good fire, books, music perhaps — then compare that with the dingy reality of Great Marlborough Street.

Marry — Marry — Marry Q.E.D.

Not Marry

No children, (no second life), no one to care for one in old age. — What is the use of working without sympathy from near & dear friendsNo children (no second life), no one to care for you in old age. What is the use of working without sympathy from those near and dear?

Freedom to go where one liked — choice of Society & little of it. — Conversation of clever men at clubs —Freedom to go where you like — the choice of company, and not much of it — clever men talking at the club.

Not forced to visit relatives, & to bend in every trifle. — to have the expense & anxiety of children — perhaps quarelling —Not forced to visit relatives, or to give way over every trifle — the expense and worry of children — quarrelling, perhaps.

Loss of time. — cannot read in the Evenings — fatness & idleness — Anxiety & responsibility — less money for books &c —Loss of time — no reading in the evenings — fatness and idleness — worry and responsibility — less money for books.

Perhaps my wife wont like London; then the sentence is banishment & degradation into indolent, idle fool —Perhaps my wife won't like London; then the sentence is banishment, and sinking into an idle fool.

Hover a line for the archivist's note.

Turn it over

On the back, the argument keeps going, because the columns had not settled anything. He heads it "It being proved necessary to Marry" — though nothing had been proved — and asks "When? Soon or Late." He mourns what he will lose ("Eheu!! I never should know French, — or see the Continent — or go to America, or go up in a Balloon…") and ends with words that are no argument at all: "There is many a happy slave —"

One honest word about the language

The back of the sheet uses slavery as a metaphor for marriage, and one clause contains a racial slur that this page does not reproduce. Darwin opposed slavery all his life, which is exactly why the casual metaphor is worth noticing rather than trimming away. Old documents are not tidy, and pretending they are is its own kind of dishonesty.

Now count: the Not Marry column is longer, with more reasons and sharper ones. Yet under the other column he wrote Marry — Marry — Marry Q.E.D. — "which was to be demonstrated," the words that end a geometry proof. He weighed nothing and struck nothing out; he argued his way to an answer and stamped it with mathematics.

Instrument one · the sheet is yours now

Rule your own line

Put a real question at the top — something still open, however small. Fill both columns. Then do what Darwin didn't: give every reason a weight from 1 to 5 and let the beam tip.

This is the question

The little numbers 1–5 beside each reason are its weight. Tap them. The beam below re-balances as you go.

Challenge: make the short column win

Make one column at least two reasons longer than the other, then use the weights to tip the beam toward the shorter one.

Now the honest line: did the beam tell you anything you didn't already know?

What Franklin actually wrote, 19 September 1772

"…my Way is, to divide half a Sheet of Paper by a Line into two Columns, writing over the one Pro, and over the other Con. Then during three or four Days Consideration I put down under the different Heads short Hints of the different Motives… When I have thus got them all together in one View, I endeavour to estimate their respective Weights; and where I find two, one on each side, that seem equal, I strike them both out… in what may be called Moral or Prudential Algebra."

Franklin also explained why hard choices feel impossible: "all the Reasons pro and con are not present to the Mind at the same time." Your reasons take turns, and whichever are in the room at 2 a.m. win at 2 a.m. His cure is subtraction: "If I judge some two Reasons con equal to some three Reasons pro, I strike out the five."

Benjamin Franklin to Joseph Priestley, London, 19 September 1772. Lord Shelburne had offered Priestley a post as his librarian; Priestley weighed it for months and accepted in December. Franklin refused to tell him what to do — only how to decide.

Game · Franklin's algebra against the clock

Where does the balance lie?

Ten sheets, nine seconds each. Every reason has a weight from 1 to 5: call the heavier side. Careful — the longer column is not always the heavier one.

Pro

Con

Instrument two · the coin

The thing a column cannot tell you

In January 2013 the economist Steven Levitt put a coin on the internet. People stuck on a real decision — quit, leave, go back to school — typed it in, gave one option to heads, and let the coin decide. He then checked on them two and six months later.

Predict: nobody had to obey the coin. Out of 100 people, how many do you think did what it said?

Here is your coin. But watch a different moment than Levitt did: not where it lands, but what you find yourself hoping for while it is still in the air.

The change you keep almost making Heads means…

The coin has no idea what you should do. What it does is force a rehearsal: for one second you get to find out how you feel about an answer without having to live with it. That half-second of relief or dread is data your columns never collected.

What Levitt found — and what he didn't

Predict before you read on: six months later, how did people whom the coin pushed into a big change feel?

At two months the coin made no clear difference to happiness. At six months, for the big decisions only, people it pushed into a change were substantially happier — quitting a job and ending a relationship moved most. Levitt's reading: when we sit on the fence, we tend to be too cautious.

Hold that loosely. The volunteers found the site through a podcast, rated their own happiness, and nobody has repeated the study. Small decisions showed nothing, and only about one in five who flipped to break a bad habit had managed it.

Instrument three · the other chair

Solomon's problem

King Solomon, the story goes, gave wise advice to everyone who came to him and made a mess of his own household. In 2014 the psychologists Igor Grossmann and Ethan Kross borrowed his name for a pattern: people reason more wisely about a friend's problem than about the same problem as their own.

In their study, people imagined a partner being unfaithful — either their own partner or a friend's. Reasoning about the friend's problem was wiser. One change closed the gap: thinking about their own problem in the third person, using their own name.

So: write your dilemma the way you'd say it in your head. Then watch the page hand it to somebody else.

Say it in the first person, the way it actually sounds in there Give the person in the other chair a name Their problem, then

…

They have asked you what you think. Don't be gentle and don't be clever — just answer them. Is that what you were going to do?

How strong is this? Real, but it comes from one research team and fairly small samples. Treat it as a trick worth trying, not a law of nature.

Instrument four · the ten-year dial

Two kinds of sting

In 1994 the psychologists Tom Gilovich and Victoria Medvec asked people what they regretted. In the short run people mostly named things they did; looking back over a whole life, they named things they didn't do. It became one of psychology's most quoted findings.

Try it on yourself. Two lines, both kept small and light. Then work the dial.

Something you did that didn't work out — keep it small and everyday Something small you almost did and didn't

Choose something you can hold lightly — a message, a club, a conversation, a subject you dropped. If something heavier turns up while you're thinking, that's normal, and talking it through with someone you trust is a large part of how people work things out.

The thing you did — this week4

The thing you did — in ten years2

The thing you didn't — this week3

The thing you didn't — in ten years5

Which regret hurts more? Visitors to a Chicago psychology museum (2023 study)

Each visitor wrote one regretted action and one regretted inaction, then said which troubled them more — over the last few days, and over their life so far.

Something they didSomething they didn't do

Where regret actually lives

In 2005 Neal Roese and Amy Summerville pooled eleven datasets — 3,041 people and 4,054 regrets — and sorted them by area of life. Romance is not at the top; education is. Their explanation is the sharpest idea in this lesson: regret follows opportunity — it aches most where a door still seems open.

What people say they regret, by area of life

3,041 people · 4,054 regrets · eleven datasets. The samples lean toward educated people, so read the shape, not the exact order.

Not "where do you have regrets" — the forward-facing version: where does a door still feel open to you?

One line about that door

Six things that wobble

This subject has more folklore attached to it than any other

Two hundred and fifty years of trying to decide

The paper trail

Six things worth knowing

The mirror · not a verdict

Everything you wrote, handed back

Tell me where I got it wrong. This line is yours and I don't get a reply.

I am counting characters and clicks. You are the one who was there. Nothing on this page has been graded, scored, or turned into a type — and none of it says what kind of person you are.

The graded bit · eight questions

This one is scored — and it is not about you

Everything above is unscored on purpose. This is the opposite: eight questions about the story, the dates and the evidence. Getting them wrong costs nothing except the pleasure of the feedback.

Sources

Where the facts come from

Every date, number and quote in this lesson was checked against these sources. Links go to the original papers or scholarly editions.

Charles Darwin, "This is the Question / Marry — Not Marry" memorandum [July 1838], Cambridge University Library DAR 210.8.2 — Darwin Correspondence Project: Darwin's notes on marriage (date, pencil, interlineations, cancelled lines, proposal) · Darwin Online transcription
Darwin's earlier note [after 7 April 1838], DAR 210.8.1 — Darwin Online transcription
Benjamin Franklin to Joseph Priestley, 19 September 1772, Papers of Benjamin Franklin vol. 19 — Founders Online (text and editorial note)
Steven D. Levitt (2021), "Heads or Tails: The Impact of a Coin Toss on Major Life Decisions and Subsequent Happiness," Review of Economic Studies 88(1) — NBER Working Paper 22487 (launch date, 22,511 flips, 63% compliance, 2- and 6-month results, bad habits)
Thomas Gilovich & Victoria Husted Medvec (1994), "The temporal pattern to the experience of regret," JPSP 67(3) — doi:10.1037/0022-3514.67.3.357
Rachel Richardson & Thomas Gilovich (2023), "A very public replication of the temporal pattern to people's regrets," Royal Society Open Science 10(6) — doi:10.1098/rsos.221574 · MindWorks exhibit page
Neal J. Roese & Amy Summerville (2005), "What we regret most… and why," Personality and Social Psychology Bulletin 31(9) — Miami University repository
Igor Grossmann & Ethan Kross (2014), "Exploring Solomon's paradox," Psychological Science 25(8) — University of Michigan summary
Timothy D. Wilson & Jonathan W. Schooler (1991), "Thinking too much: Introspection can reduce the quality of preferences and decisions," JPSP 60(2) — PubMed
Ap Dijksterhuis et al. (2006), "On making the right choice: The deliberation-without-attention effect," Science 311 — Kellogg record
Mark R. Nieuwenstein et al. (2015), "On making the right choice: A meta-analysis and large-scale replication attempt of the unconscious thought advantage," Judgment and Decision Making 10(1) — full text

Better Than a Dog, Anyhow