133frameworks from history’s greatest guides.

When to use: A creative project feels intimidating or joyless.

Source: Inside the Fun Factory, Max Eddy, The Mary Sue (2012), Writing for the team's own amusement and learning across departments

When to use: Self-judgment is crowding out a manageable next step.

Source: The Midnight Gospel interview, Rollin Bishop, ComicBook (2020), Choosing conversations about practicing kindness

When to use: Working through money discipline, recurring spend, unit economics, a market panic, or any moment where iron patience beats aggression.

Source: Titan by Ron Chernow

When to use: Setting up bookkeeping habits, auditing recurring spend, looking for unit-economic waste, or imposing financial discipline on a chaotic operation.

Source: Titan by Ron Chernow, Chapter 3 (Ledger A) and Chapter 25 (the dimes and daily habits)

When to use: A market panic, downturn, layoff wave, or competitor collapse, and you have cash, conviction, or both.

Source: Titan by Ron Chernow, Chapter 12 (Panic of 1873) and Chapter 6 (Cleveland Massacre)

When to use: Self-improvement, building a habit-tracking system, starting a mastermind, drafting a public letter, or any decision where persuasion beats force.

Source: The Autobiography of Benjamin Franklin

When to use: Building self-discipline, fixing a recurring personal flaw, designing a habit tracker, or operationalizing 'becoming a better person.'

Source: The Autobiography of Benjamin Franklin, Part 2 (the bold and arduous project of arriving at moral perfection)

When to use: Starting a mastermind, founders circle, weekly dinner, study group, or any structured peer-improvement society.

Source: Benjamin Franklin: An American Life by Walter Isaacson, Chapter 5: Franklin's Junto society, founded 1727

When to use: Engineering problems, 'this is impossible' claims, long quoted timelines, manufacturing or process bloat, supplier cost audits, or any moment needing bias-to-action under pressure.

Source: Elon Musk by Walter Isaacson

When to use: You are quoted an 'industry standard' cost, told a long timeline, or stuck behind 'this is how it has always been done.'

Source: Elon Musk by Walter Isaacson, Chapter 2 (the rocket-cost decomposition that founded SpaceX)

When to use: Simplifying a workflow, killing process bloat, speeding up cycle time, or rebuilding an operation from scratch.

Source: Elon Musk by Walter Isaacson, Chapter 30 (Musk's manufacturing algorithm, articulated to Tesla and SpaceX teams)

When to use: Auditing supplier prices, vendor contracts, build-vs-buy decisions, or any 'why does this cost so much' question.

Source: Elon Musk by Walter Isaacson, Chapter 47 (Musk asks engineers for the idiot index on every part)

When to use: Leading a team into something hard, deciding where to concentrate scarce resource, facing a competitor with more raw power, or wondering whether to delegate what the team needs to see you personally absorb.

Source: Plutarch's Life of Alexander and Arrian's Anabasis Alexandri

When to use: You are asking the team to absorb something hard (late nights, a pay cut, a risky pivot) and you need them to follow.

Source: Life of Alexander by Plutarch and The Campaigns of Alexander by Arrian, Plutarch on the Gedrosian Desert; Arrian on Alexander leading the cavalry charge at Granicus

When to use: You are spread across too many fronts, facing a competitor with more raw power, or struggling to focus.

Source: The Campaigns of Alexander by Arrian, The Battle of Gaugamela, 331 BC

When to use: Evaluating a theory, debating an interpretation, detecting bullshit, or paralyzed by the claim that something is just the way things are.

Source: The Beginning of Infinity by David Deutsch

When to use: Evaluating a theory, debating an interpretation, choosing between competing hypotheses, or detecting bullshit.

Source: The Beginning of Infinity by David Deutsch, Chapter 1 (the seasons example: Persephone vs axial tilt)

When to use: Paralysis from 'this is just how it is,' a problem someone declared impossible, or a moment of strategic pessimism.

Source: The Beginning of Infinity by David Deutsch, Chapter 9 (Optimism)

When to use: A problem looks unsolvable inside one discipline and you suspect the explanation lives across several.

Source: The Fabric of Reality by David Deutsch, Chapter 1

When to use: You have a plan or belief that just failed in some specific way and you are deciding whether to scrap the whole thing or fix the part that broke.

Source: The Fabric of Reality by David Deutsch, Chapter 3 (Problem-solving)

When to use: Someone dismisses a pattern, motive, or claim you noticed as not real or just a coincidence, or asks you to take a fringe idea seriously enough to argue against it properly.

Source: The Fabric of Reality by David Deutsch, Chapter 4 (Criteria for Reality)

When to use: You are about to hard code a fix for the one case in front of you, or write a rule that only covers the situations you have already thought of.

Source: The Fabric of Reality by David Deutsch, Chapter 6 (Universality and the Limits of Computation)

When to use: Someone ends a debate by saying the math proves it, the model is rigorous, or the numbers do not lie.

Source: The Fabric of Reality by David Deutsch, Chapter 10 (The Nature of Mathematics)

When to use: You are setting up how a team gives feedback, or you notice people softening real objections because of who they are talking to.

Source: The Fabric of Reality by David Deutsch, Chapter 13 (The Four Strands), the critique of Kuhn's paradigms

When to use: You are improving a tool, template, process, or system that only handles the specific cases you built it for, and you are deciding whether to bolt on another special case or change the underlying rule.

Source: The Beginning of Infinity by David Deutsch, Chapter 6, The Jump to Universality (the alphabet, positional numerals, Babbage's Analytical Engine, the genetic code)

When to use: A habit, ritual, tool, or idea has spread and persisted inside your team, product, or life, and you have never actually checked whether it survives because it helps people or because it is simply good at getting copied.

Source: The Beginning of Infinity by David Deutsch, Chapter 4, Creation (the neo-Darwinian selection argument, extended from genes to memes)

When to use: Someone hands you a rule, policy, methodology, or dismissal presented as beyond question, such as that is just how the market works, that is above your pay grade, or shut up and calculate, and you want to know whether it is a real answer or a stop sign.

Source: The Beginning of Infinity by David Deutsch, Chapter 12, A Physicist's History of Bad Philosophy (the Copenhagen interpretation, logical positivism)

When to use: You are stuck between options that all feel like compromises, and you are tempted to weigh the pros and cons harder instead of asking whether a better option exists that nobody on the list has thought of yet.

Source: The Beginning of Infinity by David Deutsch, Chapter 13, Choices (the critique of social choice theory and Arrow's impossibility theorem, extended to personal decisions)

When to use: You notice you are not allowed to question a belief, rule, or piece of advice you hold or were given, or you catch yourself enforcing a rule with because I said so instead of a reason.

Source: The Beginning of Infinity by David Deutsch, Chapter 15, The Evolution of Culture (rational memes, anti-rational memes, static society thinking)

When to use: You are planning something for the long term, such as a budget, a career path, a company roadmap, or a resource plan, and the plan's main selling point is that it is stable, self sufficient, or will not need to change.

Source: The Beginning of Infinity by David Deutsch, Chapter 17, Unsustainable (Easter Island's static culture, the falsified Ehrlich resource-collapse predictions)

When to use: Making a decision through an ideological lens, designing incentives, hiring senior leadership, or fixing a culture where rules get bent quietly.

Source: From Third World to First by Lee Kuan Yew

When to use: You are debating a policy or strategy through an ideological lens (left/right, agile/waterfall, B2B/B2C orthodoxy) instead of through results.

Source: From Third World to First by Lee Kuan Yew, The pragmatist doctrine across his three decades as Prime Minister

When to use: Designing incentives, hiring senior leadership, setting conflict-of-interest policy, or fixing a culture where rules get bent quietly.

Source: From Third World to First by Lee Kuan Yew, Chapters 13–15: the Corrupt Practices Investigation Bureau

When to use: Anxious, stuck in resentment, wrestling with mortality or vanity, ruminating about what others think, troubled by the body, or asking what to do today.

Source: Meditations by Marcus Aurelius

When to use: Anxiety, resentment, or spiraling about an outcome, another person, the past, or anything you can't directly move.

Source: Meditations by Marcus Aurelius, Book 9.6 and Book 12.26 (the dichotomy, from Epictetus)

When to use: Catastrophizing, status panic, an offense that feels enormous, or a decision distorted by being too close to it.

Source: Meditations by Marcus Aurelius, Book 7.48 and Book 9.30 (the cosmic perspective)

When to use: Procrastination, trivial grievances, over-investing in things that won't matter, or losing the thread of what's important.

Source: Meditations by Marcus Aurelius, Book 2.11 and Book 4.17

When to use: Deciding what to build, evaluating a startup or investment thesis, choosing how to think about a regulated incumbent industry, or fighting the pessimism that says technology can't make things better.

Source: Marc's essays at a16z.com (2011–2023)

When to use: Picking what to build, evaluating an incumbent industry for disruption, or assessing whether your own company is the new-wave or old-wave entrant in your category.

Source: “Why Software Is Eating the World” by Marc Andreessen (WSJ, August 20, 2011)

When to use: Stuck in analysis, complaining about a problem, or watching an institution fail to do something obvious. Especially in regulated or “mature” sectors that have stopped shipping.

Source: “It's Time to Build” by Marc Andreessen (a16z.com, April 18, 2020)

When to use: When pessimism, doom narratives, or institutional caution are framing a decision that should be evaluated on whether it raises or lowers capability.

Source: “The Techno-Optimist Manifesto” by Marc Andreessen (a16z.com, October 16, 2023)

When to use: Building a brand, raising a story-led round, designing a community product, or stress-testing whether your narrative is a moat or a hallucination.

Source: Billion Dollar Loser (Wiedeman) + The Cult of We (Brown & Farrell)

When to use: When your product is commoditized on paper and you need a defensible differentiator, or when you suspect competitors are out-narrating you.

Source: Billion Dollar Loser by Reeves Wiedeman, Chapters 3–6 (the early WeWork pitch)

When to use: Raising a round where the unit economics are nascent and you need to sell the future, or evaluating a competitor's pitch you suspect is narrative-only.

Source: The Cult of We by Eliot Brown and Maureen Farrell, Chapters 8–11 (Masayoshi Son and the WeWork raise)

When to use: Pre-IPO companies, late-stage startups raising on private narratives, or any company whose growth has outrun its ability to explain unit economics to a hostile reader.

Source: The Cult of We by Eliot Brown and Maureen Farrell; WeWork S-1 (Aug 14, 2019), Chapters 12–15 (the six weeks between filing and ouster)

When to use: Wrestling with how time is being spent, working through anger you don't want to be governed by, navigating a court (corporate or political) where flattery is expected, or designing a personal practice you can sustain.

Source: Letters from a Stoic + On the Shortness of Life + On Anger

When to use: Stuck in a routine you didn't pick, postponing the real work until 'later,' or watching a year pass without being able to say what you spent it on.

Source: De Brevitate Vitae (On the Shortness of Life) by Seneca, §§ 1–3 and 7–10 (the audit of how time is wasted)

When to use: Designing a personal philosophy practice that survives more than a week, building a journaling habit that produces decisions instead of feelings, or wanting to study a tradition by walking it daily instead of reading about it.

Source: Epistulae Morales ad Lucilium (Letters to Lucilius) by Seneca, Letters 1, 7, 16, 26, 47 (representative practical letters)

When to use: Triggered by a message, a meeting, or a person, and about to respond from the trigger rather than from your considered judgment. Or designing protocols (for yourself or a team) that put time between provocation and reaction.

Source: De Ira (On Anger) by Seneca, Book I §§ 1–7 and Book II §§ 28–29 (the daily examination)

When to use: Summon Ricky Gervais's full comedic operating system: making something funny without making it false, building a character whose blind spot is the joke, deciding whether an offensive bit should be cut or kept, wrestling with cringe and awkward-comedy premises, workshopping stand-up toward a tight hour, or defending a joke that got a reaction you didn't intend.

Source: The Office, After Life, and the Netflix stand-up specials (Humanity, SuperNature, Armageddon, Mortality)

When to use: Use when the user has a rough idea, a bit that isn't landing, a pile of observations that won't cohere, a set that runs long or sags, or a taboo subject they want to be funny about without being merely shocking. Also for finding a persona and point of view, structuring a tight hour, deciding what to cut, and editing lines down to the laugh.

Source: Ricky Gervais's stand-up specials and stated method (Animals, Politics, Fame, Science, Humanity, SuperNature, Armageddon, Mortality) plus interviews on writing by incubation and touring a work-in-progress hour to iron out the kinks before taping., the-talks.com/interview/ricky-gervais/ ; nofilmschool.com/screenwriting-tips-ricky-gervais ; en.wikipedia.org/wiki/Ricky_Gervais

When to use: Use when writing a joke, bit, sketch, or satire that touches a taboo or sensitive subject and you want to know whether it holds up, or when something's been called 'offensive' and you need to tell a real craft fault from a mere reaction. Covers subject vs. target, irony vs. endorsement, the comedian's voice vs. a character's, intent and defensibility, and edgy-for-shock vs. edgy-with-a-point.

Source: Ricky Gervais's stated positions on free speech and offence: 'Offence is the collateral damage of free speech' (Twitter/X, 1 Sep 2014), the subject-vs-target distinction and irony defence of SuperNature (BBC The One Show, Deadline, The Spectator, May 2022), and 'the truth is more devastating than a lie' (The Talks)., 'Most offence comes from when people mistake the subject of a joke with the actual target': SuperNature defence, 2022

When to use: Use when writing a comedy character, sitcom, mockumentary, or cringe scene that lives on someone deluding themselves in public. Also when jokes land but no one cares about the people, when a show gets laughs but has no heart, or when a 'cringe' scene reads as cruelty instead of funny-and-sad.

Source: Ricky Gervais's work on The Office (2001–2003), Extras, Derek, and After Life (2019–2022), and his stated craft: make the ordinary extraordinary, find the funny in the true, and pair pathos with a character's blind spot., David Brent, The Office (UK); Tony Johnson, After Life

When to use: Summon Marie Skłodowska-Curie's full operating mindset into the current chat. Use whenever the user is standing before something they do not understand and are tempted to fear it, facing an intractable problem that will yield only to years of unglamorous physical work, drowning in qualitative impressions where an exact measurement would cut through, or deciding what to do with recognition, credit, or money that the work has produced. Channels her method (replace fear with comprehension, grind the problem into a physical process, let measurement lead, give the work away) as one operating philosophy, addressed to a peer at the bench rather than a student in a lecture hall.

Source: Marie Curie, Pierre Curie (1923) and Autobiographical Notes; her 1903 doctoral thesis Recherches sur les substances radioactives; and Ève Curie, Madame Curie: A Biography (1937).

When to use: Use for a hard extraction, purification, or long-horizon problem: finding the one real signal buried in a mountain of noise, isolating a single true cause from a confounded mess, separating what matters from what merely surrounds it, any task where the answer exists but is dilute, and the only path is a repeatable process measured batch by batch until the target is isolated, weighed, and in hand.

Source: Marie Curie's isolation of radium (1898–1902); her doctoral thesis Recherches sur les substances radioactives (1903); Ève Curie, Madame Curie: A Biography (1937)., Isolation of ~0.1 g pure radium chloride from several tons of pitchblende via the piezoelectric-quartz electrometer and fractional crystallization; radium-isolation method published without patent.

When to use: When the user is frozen by something they have not yet looked at squarely (a diagnosis, a scary technical problem, a decision, a confrontation, a grief) and is reacting to the vague shape of it rather than the thing itself. Also when they need to keep working through genuine adversity or grief without drama.

Source: Theme most associated with Marie Curie ('Nothing in life is to be feared, it is only to be understood...'), grounded in her verified method and life; see Ève Curie, Madame Curie: A Biography (1937)., On fear, understanding, and endurance

When to use: When deciding whether to patent, protect, or freely give away work; when status, credit, or recognition start steering decisions that should be steered by the truth; when public noise, scandal, or reputation-management pulls attention off the actual problem; or when measuring yourself by what you have done rather than what remains to be done.

Source: Marie Curie's and Pierre's deliberate refusal to patent the radium-isolation process (published freely so any lab could produce radium), her recorded reasoning that radium 'belongs to all people,' and her documented indifference to fame and money through the 1911 press scandal., Marie Curie, letter to her brother Józef (1894); Ève Curie, Madame Curie: A Biography (1937).

When to use: Knocked down by a setback and tempted to quit, caged by a limiting belief or someone else's definition of you, sitting on an injustice you keep meaning to act on, caught in a conflict or rivalry you could escalate or heal, or searching for the one gift that is yours to give in service of something bigger than yourself.

Source: Bob Marley's songs, life, and documented interviews: Redemption Song, Get Up Stand Up, and One Love; the December 1976 assassination attempt and Smile Jamaica; the 1978 One Love Peace Concert

When to use: You're held back not by an outside obstacle but by an inside one: a limiting belief, someone else's definition of you, a box you never chose ('people like me don't,' 'I could never,' 'I'm not that kind of person'). Also when you're fighting an external battle while still wearing an internal chain.

Source: Bob Marley, 'Redemption Song' (Uprising, 1980), adapting Marcus Garvey's 1937 speech, 'Emancipate yourselves from mental slavery; none but ourselves can free our minds', recorded when Marley was already terminally ill, stripped to voice and acoustic guitar; the line adapts Marcus Garvey's speech at Menelik Hall, Nova Scotia, 31 October 1937

When to use: You see an injustice or a wrong (at work, in your community, in your own life) and you keep waiting: for a better time, for more authority, for someone else to go first, or for a reward that never comes. Turn conviction into action today.

Source: Bob Marley & Peter Tosh, 'Get Up, Stand Up' (Burnin', 1973); Marley playing Smile Jamaica two days after being shot, December 1976, 'Get up, stand up, stand up for your right', the song's rejection of waiting for a reward 'someday'; and 'the people who are trying to make this world worse aren't taking a day off, how can I?' on performing at Smile Jamaica, 5 December 1976

When to use: De-escalating a conflict, rivalry, or feud (family, team, business, community) that you could either escalate or heal. Especially when you've been wronged and revenge is tempting.

Source: Bob Marley, 'One Love / People Get Ready' (Exodus, 1977); the One Love Peace Concert, Kingston, 22 April 1978, After surviving the December 1976 assassination attempt, Marley joined the hands of rival leaders Michael Manley (PNP) and Edward Seaga (JLP) on stage during 'Jamming' at the One Love Peace Concert, 22 April 1978

When to use: When the user is imitating a competitor, running a borrowed playbook, or performing the role their title is supposed to require.

Source: Tobi Lütke: 21 Years of Building Shopify, his conversation with David Senra on the Founders interview show, plus his own essays., content/knowledge/interviews/011-tobi-l-tke-21-years-of-building-shopify.md

When to use: Use when the user is tempted to add a second product line, expand the menu, take a dilutive round, franchise or sell the company, chase margin over service, or diversify instead of getting devastatingly good at the one thing customers actually come back for. Also use when deciding what to refuse, what detail to obsess over next, or how to keep ownership and control through a downturn.

Source: Todd Graves in conversation with David Senra on the Founders interview show, published 2025-11-09., content/knowledge/interviews/019-how-todd-graves-built-raising-canes.md

When to use: Use when the user is about to fight a bigger, lower-cost rival on price, when a co-founder or investor wants to harvest a comfortable business instead of build a mission, when the user needs to pick a niche defensible enough to compound in quietly, or when they treat every peer in their category as a threat rather than a potential ally.

Source: John Mackey in conversation with David Senra on the Founders interview show (44 Years of Building Whole Foods), and his book "Conscious Capitalism" (2013)., content/knowledge/interviews/023-john-mackey-44-years-of-building-whole-foods.md

When to use: Use when positioning or launching a product, writing copy that lists features instead of feelings, deciding who to work with or for, sitting in a room where everyone agrees with you, or holding back hard feedback you are afraid to deliver.

Source: Jimmy Iovine's conversation with David Senra on the Founders interview show, content/knowledge/interviews/006-jimmy-iovine-building-interscope-records-beats-by-dre.md

When to use: Use when choosing between career paths or projects, when the question has become 'what would make me happy', when the work is easy but small, or when someone is copying another founder's playbook instead of building something true to who they actually are.

Source: Daniel Ek in conversation with David Senra on the Founders interview show, 2025, content/knowledge/interviews/009-daniel-ek-spotify-david-senra.md

When to use: Use when a bigger competitor is copying you or about to, when deciding where the next quarter of engineering goes, when defending a feature list as if it were a moat, or when the roadmap is full of surface polish and nothing durable. Runs a ninety day clone test over every feature and asset, sorts what survives into network effects, owned hardware, distribution and ecosystem, or vision plus delivery record, then moves budget and headcount into the hard column.

Source: Evan Spiegel in conversation with David Senra on the Founders interview show, "Evan Spiegel, Snapchat: Building a Multi-Billion Dollar Company", content/knowledge/interviews/018-evan-spiegel-snapchat-building-a-multi-billion-dollar-compan.md

When to use: Use when a hard technical or product problem has already resisted your first few clever attempts, when experts have told you it cannot work, when you keep changing several things at once and can no longer tell what helped, when a run of failures has you ready to quit, or when you are hunting for one brilliant insight to skip the grind.

Source: James Dyson's autobiographies, Against the Odds and Invention: A Life of Learning Through Failure, plus his conversation with David Senra on Founders., content/knowledge/founders/014-the-stubborn-genius-of-james-dyson.md

When to use: Use when the user is frozen on a high-stakes decision, is optimizing for short-term approval, is being pulled off-course by whatever is loudest this quarter, or is so afraid of losing what they built that they cannot act. Also use when a team has no written mission and every stakeholder effectively gets a veto.

Source: Brian Armstrong in conversation with David Senra on the Founders interview show, plus Armstrong's 2020 Coinbase mission post., content/knowledge/interviews/024-brian-armstrong-when-washington-tried-to-kill-coinbase.md

When to use: Use when the user is about to make a decision whose worst case they have never actually named, is asking for a forecast instead of a position, is stacking on new habits, tools, tactics or advice when the real problem is something they should stop, is over concentrated in one job, one client, one relationship or one bet, or is taking advice from people who pay nothing if they turn out to be wrong. Also use when someone frames a risk as an average, as in a project that works out on average, without noticing that one bad draw removes them from the game entirely.

Source: The Incerto by Nassim Nicholas Taleb: Fooled by Randomness (2001), The Black Swan (2007), The Bed of Procrustes (2010), Antifragile (2012), and Skin in the Game (2018). Via negativa, the barbell strategy and the Lindy effect are developed in Antifragile. Ruin, ergodicity and the four feet deep river rule come from Skin in the Game.

When to use: Before crediting a big win (yours or someone else's) as proof of skill, or before making a bet where a rare bad outcome would be catastrophic.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Chapter Two, A Bizarre Accounting Method (Russian Roulette, Alternative History)

When to use: When you are about to trust someone's, or your own, run of success: a fund manager's returns, a trading rule that backtested beautifully, or a bestselling how-they-did-it book.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Part Two, Monkeys on Typewriters, Chapters Eight and Nine (Too Many Millionaires Next Door, It Is Easier to Buy and Sell Than Fry an Egg)

When to use: When you are checking a portfolio, a metric, or a project's progress far more often than the true rate of change in the underlying reality justifies, and it is costing you emotional energy or bad decisions.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Chapter Three, Philostratus in Monte Carlo: On the Difference Between Noise and Information, reinforced in Chapter Twelve, Gamblers' Ticks and Pigeons in a Box

When to use: When you are about to make a bet, forecast, or decision and you catch yourself, or someone else, stating only how likely an outcome is without stating how large that outcome would be.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Chapter Six, Skewness and Asymmetry

When to use: When you are evaluating the current top performer in a field, a trader, a strategy, a company, a hire, and you are tempted to treat their recent dominance as proof of superior skill.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Chapter Five, Survival of the Least Fit, A Review of Market Fools of Randomness Constants

When to use: Before entering a position, launching a bet on a belief, or committing capital or time to a thesis, when you have not yet named what would prove the thesis false.

Source: Fooled by Randomness by Nassim Nicholas Taleb, Chapter Seven, The Problem of Induction, Popper's Answer, Pascal's Wager

When to use: Use when a surprising event just happened and people (including the user) are rushing to say either it could never have been predicted or, worse, that everyone saw it coming all along. Also use when the user labels an ordinary bad surprise a Black Swan to excuse a failure, or wants to know whether a risk is worth specifically preparing for versus generically preparing for the unknown.

Source: The Black Swan by Nassim Nicholas Taleb, Prologue: On the Plumage of Birds

When to use: Use before trusting a sample average, a historical track record, a risk model, or a forecast in any domain, especially finance, careers, product sales, or company size. Use it whenever someone says a large sample settles the question, or that a single event could not possibly matter much to the total.

Source: The Black Swan by Nassim Nicholas Taleb, Chapter 3: The Speculator and the Prostitute

When to use: Use when someone points to years of steady results, a clean safety record, or a pattern that has never broken as the reason to keep doing what they are doing. Use it to pressure-test any claim of the form this has always worked, especially from a bank, an institution, or anyone whose good years have all come from the same untested source.

Source: The Black Swan by Nassim Nicholas Taleb, Chapter 4: One Thousand and One Days, or How Not to Be a Sucker

When to use: Use whenever a clean, satisfying explanation for a success, a failure, or a historical event is being accepted mainly because it is easy to remember and tell, not because it was tested. Especially useful before writing a postmortem, a case study, a biography-style success story, or any after the fact account of why something happened.

Source: The Black Swan by Nassim Nicholas Taleb, Chapter 6: The Narrative Fallacy

When to use: Use before adopting advice from a successful person, a case study, a bestselling book, a fund manager's track record, or any story of the form here is what the winners had in common. Also use when evaluating whether a practice, treatment, or strategy is safe based only on the visible survivors of it.

Source: The Black Swan by Nassim Nicholas Taleb, Chapter 8: Giacomo Casanova's Unfailing Luck: The Problem of Silent Evidence

When to use: Use whenever someone reasons about a real-world risk using odds, dice, coin flips, casino logic, or a model with known, fixed rules, especially in finance, insurance, or any domain where the true rules of the game are not fully known. Also use when a credentialed, exam-trained expert is confidently applying textbook probability to an open-ended real situation.

Source: The Black Swan by Nassim Nicholas Taleb, Chapter 9: The Ludic Fallacy, or The Uncertainty of the Nerd

When to use: Use when deciding how much to trust a forecast, a risk model, or a statistical measure before acting on it, especially in finance, policy, health, or any decision with an open-ended payoff in a domain capable of extreme outcomes. Use it to decide whether more modeling effort will help or whether the honest answer is to change your exposure instead.

Source: The Black Swan by Nassim Nicholas Taleb, Postscript Essay: VI, The Fourth Quadrant, and VII, What to Do with the Fourth Quadrant

When to use: Use when someone offers you advice, a recommendation, or a strong opinion (a stock tip, a pundit's forecast, a consultant's plan, a friend's certainty about a decision) and you have not yet checked what that person stands to lose if they are wrong. Also use before you publish your own strong opinion, to check whether you would say it if it cost you something.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 1, Why Each One Should Eat His Own Turtles: Equality in Uncertainty (A Customer Is Born Every Day, Talking One's Book)

When to use: Use when you are trying to predict or shape a market, a menu, a policy default, or a cultural shift, and you find yourself counting heads to find the majority preference. Also use when a small, intense, uncompromising group of customers, employees, or critics seems to have influence wildly out of proportion to its size.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 2, The Most Intolerant Wins: The Dominance of the Stubborn Minority

When to use: Use when you are about to accept guidance from someone with impressive credentials (a think tank report, a pundit's column, a consultant's deck, a policy paper) on a matter that touches real, concrete life, and you have not yet checked whether that person has firsthand, costly experience with the thing they are pronouncing on.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 6, The Intellectual Yet Idiot

When to use: Use when you are deciding how much to trust an activist's, whistleblower's, journalist's, or employee's public position, or when you yourself are weighing whether to take an unpopular stand and want an honest picture of what you actually have to lose.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 4, The Skin of Others in Your Game (A Mortgage and Two Cats, Finding Hidden Vulnerabilities)

When to use: Use when you are choosing between candidates for a hire, a manager, an advisor, or a service provider, and you notice yourself favoring the more articulate, better dressed, or more credentialed option without having checked their actual track record under real stakes.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 9, Surgeons Should Not Look Like Surgeons (Looking the Part, The Green Lumber Fallacy, A BS Detection Heuristic)

When to use: Use when evaluating a company's, cause's, or person's publicly advertised ethical stance (an environmental campaign, a charity pitch, a values statement, your own urge to publicly announce a good deed), or when someone asks how to actually do good in the world.

Source: Skin in the Game by Nassim Nicholas Taleb, Chapter 13, The Merchandising of Virtue (The Virtue Merchants, Unpopular Virtue, Take Risk)

When to use: Use when a consequential business, investment, acquisition, hiring, or resource-allocation decision needs a patient owner-oriented analysis.

Source: Berkshire Hathaway shareholder letters, 1977-2024, by Warren E. Buffett, Full official archive, especially 1977, 1986, 1989, 1996, 2014, and 2024

When to use: Use when evaluating a business model, budget, acquisition, project, or financial statement whose reported profit may differ from economic cash generation.

Source: Berkshire Hathaway 1986 shareholder letter by Warren E. Buffett, 1986 letter, purchase-price accounting and owner earnings discussion

When to use: Use when a decision feels exciting but depends on unfamiliar technology, economics, regulation, behavior, or forecasting.

Source: Berkshire Hathaway 1996 shareholder letter by Warren E. Buffett, 1996 letter, common stock investments section

When to use: Use when deciding whether to reinvest profits, fund a new initiative, acquire a company, repay debt, hold cash, or return capital.

Source: Berkshire Hathaway shareholder letters by Warren E. Buffett, 1980, 1982, and 1984 letters, retained earnings and capital allocation

When to use: Use before taking debt, signing guarantees or long-duration contracts, setting cash reserves, or evaluating whether a plan can survive a severe interruption.

Source: Berkshire Hathaway shareholder letters by Warren E. Buffett, 1989, 2001, 2002, 2018, and 2023 letters

When to use: Use when evaluating a company acquisition, strategic partnership, major vendor commitment, or other transaction that can become emotionally difficult to stop.

Source: Berkshire Hathaway shareholder letters by Warren E. Buffett, 1989 acquisition criteria and 2014 fiftieth-anniversary letter

When to use: Use when a decision is emotionally charged, politically distorted, complex across disciplines, or vulnerable to avoidable stupidity.

Source: Poor Charlie's Almanack and Charles T. Munger's 2014 Berkshire Hathaway shareholder-letter essay, Elementary Worldly Wisdom, Psychology of Human Misjudgment, USC 2007 address, and Vice Chairman's Thoughts

When to use: Use when the path to success is vague, a plan has too many moving parts, or preventing failure is more tractable than predicting a winner.

Source: Poor Charlie's Almanack by Charles T. Munger, edited by Peter D. Kaufman, Talks on elementary worldly wisdom and inversion, with explicit credit to Carl Gustav Jacob Jacobi

When to use: Use when stated goals and actual behavior diverge, a metric is being gamed, advice may be conflicted, or an organization keeps producing the same unwanted result.

Source: Poor Charlie's Almanack by Charles T. Munger, edited by Peter D. Kaufman, The Psychology of Human Misjudgment, reward and punishment superresponse tendency

When to use: Use before a high-pressure sale, crowd-driven decision, escalation of commitment, charismatic pitch, crisis response, or unanimous meeting.

Source: Poor Charlie's Almanack by Charles T. Munger, edited by Peter D. Kaufman, The Psychology of Human Misjudgment

When to use: Use when designing a holding company, multi-business organization, acquisition operating model, headquarters, delegation system, or succession plan.

Source: Charles T. Munger, Vice Chairman's Thoughts: Past and Future, Berkshire Hathaway 2014 shareholder letter, 2014 fiftieth-anniversary letter, Munger's first-person essay

When to use: Use when choosing a partner, repairing a relationship, designing delegation, negotiating a long-term agreement, or evaluating a culture that claims to value trust.

Source: Poor Charlie's Almanack and Charles T. Munger's USC Law School commencement address, USC Law School commencement address, May 13, 2007

When to use: Use this after something has gone badly and the sting is still fresh: a failed launch, a blown deadline, a relationship that broke, a decision you got publicly wrong, a pattern of mistakes you keep repeating without naming. Also use it when you are stuck between a goal and a problem and cannot tell which is which, when you need to reach the root cause instead of the excuse, or when you are about to make a big call and want to weight the opinions around you by believability rather than by volume. Runs the 5-Step Process on the situation, forces the diagnosis down to a root cause stated as something about a person rather than an event, checks for the ego barrier and the blind spot barrier, and ends by handing you one written principle for the next time this shape of problem shows up. Not for investment or allocation questions, which Dalio refuses.

Source: Principles: Life and Work by Ray Dalio (Simon and Schuster, 2017), Life Principle 1.7 and the 5-Step Process, together with the principles Dalio publishes himself at principles.com and his 2017 TED talk on building an idea meritocracy.

When to use: You understand a problem intellectually and still cannot act on it, nothing feels meaningful, or more information keeps failing to help.

Source: Awakening from the Meaning Crisis (lecture series) by John Vervaeke, Awakening from the Meaning Crisis, lecture series

When to use: Advice keeps failing, you have read everything and changed nothing, or you can explain the solution perfectly and still cannot perform it.

Source: Awakening from the Meaning Crisis (lecture series) by John Vervaeke, Awakening from the Meaning Crisis, lecture series

When to use: You are overwhelmed by options, cannot tell what matters, or keep attending to the wrong thing despite knowing better.

Source: Awakening from the Meaning Crisis (lecture series) by John Vervaeke, Awakening from the Meaning Crisis, lecture series

When to use: You are choosing habits or practices, a practice that used to work has curdled, or you want change that lasts beyond enthusiasm.

Source: Awakening from the Meaning Crisis (lecture series) by John Vervaeke, Awakening from the Meaning Crisis, lecture series

When to use: Use when you need to size up a founder, a business decision, or your own situation the way Senra sizes up a subject before he will trust a lesson from it.

Source: Founders Podcast by David Senra, Recurring pattern across the full catalog, especially the Rockefeller, Elon Musk, Daniel Ek, James Dyson, and Todd Graves episodes

When to use: You are about to base a decision on what someone said a founder, a competitor, or an expert believes or did, and you have not gone to that person's own words yet.

Source: Founders Podcast by David Senra, Reading pattern across the catalog: Steve Jobs in His Own Words, 38 Letters John D. Rockefeller Wrote to His Son, 400 Pages of Warren Buffett and Charlie Munger in Their Own Words, Lessons from Jeff Bezos's Shareholder Letters, Napoleon: His Written and Spoken Words

When to use: You or someone you are evaluating is waiting to feel qualified, waiting for proof, or asking whether they are good enough before they start or commit further.

Source: Founders Podcast by David Senra, 38 Letters John D. Rockefeller Wrote to His Son, and the interview episodes with Daniel Ek (Spotify) and Michael Dell

When to use: You are deciding whether to sell, dilute, partner, or hand off control of something you built, or you are trying to understand why someone else made a decision that did not maximize money.

Source: Founders Podcast by David Senra, The Stubborn Genius of James Dyson, and the interview episodes with Evan Spiegel, Todd Graves (Raising Cane's), and Jason Fried

When to use: You are making a pricing, product, or growth decision by asking what makes the most money right now, instead of what serves the customer best.

Source: Founders Podcast by David Senra, Rockefeller's Autobiography, and the interview episodes with Daniel Ek (Spotify) and Todd Graves (Raising Cane's), each independently citing Henry Ford's line that money comes as a result of service

When to use: You are hunting for new advice, a new book, or a new expert for a problem, when a source you already trust and have not revisited in years likely already has the answer.

Source: Founders Podcast by David Senra, Rockefeller covered three separate times across the catalog (How Rockefeller Worked, 38 Letters, Rockefeller's Autobiography), and Steve Jobs covered twice (Make Something Wonderful, How Steve Jobs Kept Things Simple)

When to use: Use when you have an idea, an opportunity, or a belief you are holding onto, and you want the compressed, no filler version of whether it is actually worth your time.

Source: Derek Sivers, across Anything You Want, Hell Yeah or No, How to Live, and Useful Not True, Recurring across all five books

When to use: You are deciding whether to take on a commitment, opportunity, or request, and you notice you are talking yourself into a lukewarm yes.

Source: Hell Yeah or No by Derek Sivers, Title essay, originally published August 26, 2009, expanded into the 2020 book

When to use: You have an idea, a skill, or a piece of knowledge you are dismissing as too basic or too obvious to share, teach, or build something around.

Source: Derek Sivers, essay Obvious to You. Amazing to Others., sive.rs/obvious

When to use: You are stuck rating or protecting an idea instead of building anything, or you are looking for a business idea instead of noticing the problem already in front of you.

Source: Anything You Want by Derek Sivers, The CD Baby origin story, built to sell his own CD before anyone else asked

When to use: You are stuck between two approaches that seem to contradict each other, such as independence versus commitment, or mastering one thing versus staying a beginner, and you are trying to resolve it into a single correct answer.

Source: How to Live by Derek Sivers, 27 chapters, each fully convinced of a different way to live

When to use: You are choosing between goals and one option is status, money, or connections that could be given to you, while another is a skill that can only be earned.

Source: How to Live by Derek Sivers, Chapter, Master something

When to use: You are stuck defending or attacking a belief as factually correct, when the real question is whether holding it is actually helping you act.

Source: Useful Not True by Derek Sivers, The book's central argument

When to use: Use when you are stuck between wanting to achieve something and wanting to be liked, as if you have to choose, or when you need to think through something messy by writing it out rather than solving it in your head.

Source: Visakan Veerasamy, Friendly Ambitious Nerd and the visakanv.com essay archive, Recurring across the essay archive

When to use: You have an ambition or a piece of work you are holding back on because it would look strange, embarrassing, or premature to the people around you.

Source: Visakan Veerasamy, essay Greatness is Deviance, visakanv.com/blog/greatness-is-deviance

When to use: You are trying to think through something confusing or emotionally loaded and you keep waiting until you understand it before writing anything down.

Source: Visakan Veerasamy, essay Word Magic, visakanv.com/blog/word-magic, and the 1000wordvomits project begun 2012

When to use: You are diluting a piece of work, a message, or a standard for yourself to make it acceptable to the average person, instead of aiming it at the people it is actually for.

Source: Visakan Veerasamy, essay Most People, visakanv.com/blog/most-people

When to use: You feel like a contradiction, too ambitious to fit in, too nerdy to be taken seriously, too sensitive to compete, and you have not yet found a name for what you actually are.

Source: Visakan Veerasamy, essay Friendly Ambitious Nerd, visakanv.com/blog/friendly-ambitious-nerd

When to use: Evaluating a fragmented industry for a roll-up, sizing up a big and messy deal, deciding whether to keep or cut an executive, planning the first 100 days after an acquisition, or absorbing a loss without spiraling.

Source: How to Make a Few Billion Dollars by Brad Jacobs (2024)

When to use: You're sizing up whether to enter a fragmented industry or chase a large, complicated deal, and you need a real test instead of a gut feeling.

Source: How to Make a Few Billion Dollars by Brad Jacobs (2024), The industry-research method behind United Waste Systems, United Rentals, XPO, and QXO

When to use: Planning or running the first 100 days after an acquisition, merger, or major reorg, when the deal is done and the real work of combining two organizations is about to start.

Source: How to Make a Few Billion Dollars by Brad Jacobs (2024), The post-acquisition integration playbook behind United Rentals and XPO

When to use: Deciding whether to hire, keep, promote, or let go of an executive or key team member, or designing a hiring process that filters harder than a resume review.

Source: How to Make a Few Billion Dollars by Brad Jacobs (2024), The four-quality hiring filter and the resignation test

When to use: Use when choosing a startup idea, testing demand, cutting a first version, protecting maker time, deciding whether to raise, or choosing ambitious work over prestigious work.

Source: Paul Graham's essays at paulgraham.com

When to use: Use when a product has few users, the acquisition plan is vague, or the team wants to automate before it understands what users value.

Source: Do Things that Don't Scale by Paul Graham (2013), Manual user recruitment and the fragile early product

When to use: Use when runway is becoming a concern, fundraising is being treated as inevitable, or founders have avoided doing the survival arithmetic.

Source: Default Alive or Default Dead? by Paul Graham (2015)

When to use: Use when meetings fragment a builder's day, important creative work keeps slipping, or a manager schedule is being imposed on makers.

Source: Maker's Schedule, Manager's Schedule by Paul Graham (2009)

When to use: Use when choosing what to work on, changing fields, feeling trapped by prestige, or trying to turn curiosity into a serious project.

Source: How to Do Great Work by Paul Graham (2023)