Harry Potter and the Methods of Rationality | Petunia married a professor, and Harry grew up reading science and science fiction.

Main menu Skip to primary content Skip to secondary content Contents Author’s Notes Science Fan Art More Info Center for Applied Rationality Update Notifications Latest note: Mar 14 Harry Potter and the Methods of Rationality HPMOR.com is an authorized, ad-free mirror of Eliezer Yudkowsky ‘s epic Harry Potter fanfic, Harry Potter and the Methods of Rationality (originally under the pen name Less Wrong ). The story is complete now, so the rss feed for the story mirror won’t be updating any more, although any further Author’s Notes will continue to show up in that rss feed . The canonical location of HP:MoR is currently at fanfiction.net . The author’s notes , fan art , and other info sections have moved here, as has the book-style PDF project (see below for the link). If you encounter any problems with this mirror, please contact webmaster@hpmor.com. PDF and ebook formats: Latest releases Other Formats Podcast Podcast at iTunes Discussion Warning: the following links may contain spoilers. Reddit: /r/hpmor FanFiction.net reviews TV Tropes Less Wrong Table of Contents Chapter 1: A Day of Very Low Probability Chapter 2: Everything I Believe Is False Chapter 3: Comparing Reality To Its Alternatives Chapter 4: The Efficient Market Hypothesis Chapter 5: The Fundamental Attribution Error Chapter 6: The Planning Fallacy Chapter 7: Reciprocation Chapter 8: Positive Bias Chapter 9: Title Redacted, Part I Chapter 10: Self Awareness, Part II Chapter 11: Omake Files 1, 2, 3 Chapter 12: Impulse Control Chapter 13: Asking the Wrong Questions Chapter 14: The Unknown and the Unknowable Chapter 15: Conscientiousness Chapter 16: Lateral Thinking Chapter 17: Locating the Hypothesis Chapter 18: Dominance Hierarchies Chapter 19: Delayed Gratification Chapter 20: Bayes's Theorem Chapter 21: Rationalization Chapter 22: The Scientific Method Chapter 23: Belief in Belief Chapter 24: Machiavellian Intelligence Hypothesis Chapter 25: Hold Off on Proposing Solutions Chapter 26: Noticing Confusion Chapter 27: Empathy Chapter 28: Reductionism Chapter 29: Egocentric Bias Chapter 30: Working in Groups, Pt 1 Chapter 31: Working in Groups, Pt 2 Chapter 32: Interlude: Personal Financial Management Chapter 33: Coordination Problems, Pt 1 Chapter 34: Coordination Problems, Pt 2 Chapter 35: Coordination Problems, Pt 3 Chapter 36: Status Differentials Chapter 37: Interlude: Crossing the Boundary Chapter 38: The Cardinal Sin Chapter 39: Pretending to be Wise, Pt 1 Chapter 40: Pretending to be Wise, Pt 2 Chapter 41: Frontal Override Chapter 42: Courage Chapter 43: Humanism, Pt 1 Chapter 44: Humanism, Pt 2 Chapter 45: Humanism, Pt 3 Chapter 46: Humanism, Pt 4 Chapter 47: Personhood Theory Chapter 48: Utilitarian Priorities Chapter 49: Prior Information Chapter 50: Self Centeredness Chapter 51: Title Redacted, Pt 1 Chapter 52: The Stanford Prison Experiment, Pt 2 Chapter 53: The Stanford Prison Experiment, Pt 3 Chapter 54: The Stanford Prison Experiment, Pt 4 Chapter 55: The Stanford Prison Experiment, Pt 5 Chapter 56: TSPE, Constrained Optimization, Pt 6 Chapter 57: TSPE, Constrained Cognition, Pt 7 Chapter 58: TSPE, Constrained Cognition, Pt 8 Chapter 59: TSPE, Curiosity, Pt 9 Chapter 60: The Stanford Prison Experiment, Pt 10 Chapter 61: TSPE, Secrecy and Openness, Pt 11 Chapter 62: The Stanford Prison Experiment, Final Chapter 63: TSPE, Aftermaths Chapter 64: Omake Files 4, Alternate Parallels Chapter 65: Contagious Lies Chapter 66: Self Actualization, Pt 1 Chapter 67: Self Actualization, Pt 2 Chapter 68: Self Actualization, Pt 3 Chapter 69: Self Actualization, Pt 4 Chapter 70: Self Actualization, Pt 5 Chapter 71: Self Actualization, Pt 6 Chapter 72: SA, Plausible Deniability, Pt 7 Chapter 73: SA, The Sacred and the Mundane, Pt 8 Chapter 74: SA, Escalation of Conflicts, Pt 9 Chapter 75: Self Actualization Final, Responsibility Chapter 76: Interlude with the Confessor: Sunk Costs Chapter 77: SA, Aftermaths: Surface Appearances Chapter 78: Taboo Tradeoffs Prelude: Cheating Chapter 79: Taboo Tradeoffs, Pt 1 Chapter 80: Taboo Tradeoffs, Pt 2, The Horns Effect Chapter 81: Taboo Tradeoffs, Pt 3 Chapter 82: Taboo Tradeoffs, Final Chapter 83: Taboo Tradeoffs, Aftermath 1 Chapter 84: Taboo Tradeoffs, Aftermath 2 Chapter 85: Taboo Tradeoffs, Aftermath 3, Distance Chapter 86: Multiple Hypothesis Testing Chapter 87: Hedonic Awareness Chapter 88: Time Pressure, Pt 1 Chapter 89: Time Pressure, Pt 2 Chapter 90: Roles, Pt 1 Chapter 91: Roles, Pt 2 Chapter 92: Roles, Pt 3 Chapter 93: Roles, Pt 4 Chapter 94: Roles, Pt 5 Chapter 95: Roles, Pt 6 Chapter 96: Roles, Pt 7 Chapter 97: Roles, Pt 8 Chapter 98: Roles, Final Chapter 99: Roles, Aftermath Chapter 100: Precautionary Measures, Pt 1 Chapter 101: Precautionary Measures, Pt 2 Chapter 102: Caring Chapter 103: Tests Chapter 104: The Truth, Pt 1, Riddles and Answers Chapter 105: The Truth, Pt 2 Chapter 106: The Truth, Pt 3 Chapter 107: The Truth, Pt 4 Chapter 108: The Truth, Pt 5, Answers and Riddles Chapter 109: Reflections Chapter 110: Reflections, Pt 2 Chapter 111: Failure, Pt 1 Chapter 112: Failure, Pt 2 Chapter 113: Final Exam Chapter 114: Shut Up and Do The Impossible Chapter 115: Shut Up and Do The Impossible, Pt 2 Chapter 116: Aftermath, Something to Protect, Pt 0 Chapter 117: Something to Protect: Minerva McGonagall Chapter 118: Something to Protect: Professor Quirrell Chapter 119: Something to Protect: Albus Dumbledore Chapter 120: Something to Protect: Draco Malfoy Chapter 121: Something to Protect: Severus Snape Chapter 122: Something to Protect: Hermione Granger This mirror is currently maintained by Lightcone Infrastructure . Cover art by Bogdan Butnaru. Privacy & Terms Proudly powered by WordPress {"prefetch":[{"source":"document","where":{"and":[{"href_matches":"/*"},{"not":{"href_matches":["/wp-*.php","/wp-admin/*","/wp-content/uploads/*","/wp-content/*","/wp-content/plugins/*","/wp-content/themes/hpmor/*","/wp-content/themes/twentyeleven/*","/*\\?(.+)"]}},{"not":{"selector_matches":"a[rel~=\"nofollow\"]"}},{"not":{"selector_matches":".no-prefetch, .no-prefetch a"}}]},"eagerness":"conservative"}]} /* <![CDATA[ */ var s2AjaxScriptStrings = {"ajaxurl":"https://hpmor.com/wp-admin/admin-ajax.php","title":"Subscribe to this blog","nonce":"7c00049334"}; //# sourceURL=s2-ajax-js-extra /* ]]> */ {"baseUrl":"https://s.w.org/images/core/emoji/17.0.2/72x72/","ext":".png","svgUrl":"https://s.w.org/images/core/emoji/17.0.2/svg/","svgExt":".svg","source":{"concatemoji":"https://hpmor.com/wp-includes/js/wp-emoji-release.min.js?ver=6.9.4"}} /* <![CDATA[ */ /*! This file is auto-generated */ const a=JSON.parse(document.getElementById("wp-emoji-settings").textContent),o=(window._wpemojiSettings=a,"wpEmojiSettingsSupports"),s=["flag","emoji"];function i(e){try{var t={supportTests:e,timestamp:(new Date).valueOf()};sessionStorage.setItem(o,JSON.stringify(t))}catch(e){}}function c(e,t,n){e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(t,0,0);t=new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data);e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(n,0,0);const a=new Uint32Array(e.getImageData(0,0,e.canvas.width,e.canvas.height).data);return t.every((e,t)=>e===a[t])}function p(e,t){e.clearRect(0,0,e.canvas.width,e.canvas.height),e.fillText(t,0,0);var n=e.getImageData(16,16,1,1);for(let e=0;e<n.data.length;e++)if(0!==n.data[e])return!1;return!0}function u(e,t,n,a){switch(t){case"flag":return n(e,"\ud83c\udff3\ufe0f\u200d\u26a7\ufe0f","\ud83c\udff3\ufe0f\u200b\u26a7\ufe0f")?!1:!n(e,"\ud83c\udde8\ud83c\uddf6","\ud83c\udde8\u200b\ud83c\uddf6")&&!n(e,"\ud83c\udff4\udb40\udc67\udb40\udc62\udb40\udc65\udb40\udc6e\udb40\udc67\udb40\udc7f","\ud83c\udff4\u200b\udb40\udc67\u200b\udb40\udc62\u200b\udb40\udc65\u200b\udb40\udc6e\u200b\udb40\udc67\u200b\udb40\udc7f");case"emoji":return!a(e,"\ud83e\u1fac8")}return!1}function f(e,t,n,a){let r;const o=(r="undefined"!=typeof WorkerGlobalScope&&self instanceof WorkerGlobalScope?new OffscreenCanvas(300,150):document.createElement("canvas")).getContext("2d",{willReadFrequently:!0}),s=(o.textBaseline="top",o.font="600 32px Arial",{});return e.forEach(e=>{s[e]=t(o,e,n,a)}),s}function r(e){var t=document.createElement("script");t.src=e,t.defer=!0,document.head.appendChild(t)}a.supports={everything:!0,everythingExceptFlag:!0},new Promise(t=>{let n=function(){try{var e=JSON.parse(sessionStorage.getItem(o));if("object"==typeof e&&"number"==typeof e.timestamp&&(new Date).valueOf()<e.timestamp+604800&&"object"==typeof e.supportTests)return e.supportTests}catch(e){}return null}();if(!n){if("undefined"!=typeof Worker&&"undefined"!=typeof OffscreenCanvas&&"undefined"!=typeof URL&&URL.createObjectURL&&"undefined"!=typeof Blob)try{var e="postMessage("+f.toString()+"("+[JSON.stringify(s),u.toString(),c.toString(),p.toString()].join(",")+"));",a=new Blob([e],{type:"text/javascript"});const r=new Worker(URL.createObjectURL(a),{name:"wpTestEmojiSupports"});return void(r.onmessage=e=>{i(n=e.data),r.terminate(),t(n)})}catch(e){}i(n=f(s,u,c,p))}t(n)}).then(e=>{for(const n in e)a.supports[n]=e[n],a.supports.everything=a.supports.everything&&a.supports[n],"flag"!==n&&(a.supports.everythingExceptFlag=a.supports.everythingExceptFlag&&a.supports[n]);var t;a.supports.everythingExceptFlag=a.supports.everythingExceptFlag&&!a.supports.flag,a.supports.everything||((t=a.source||{}).concatemoji?r(t.concatemoji):t.wpemoji&&t.twemoji&&(r(t.twemoji),r(t.wpemoji)))}); //# sourceURL=https://hpmor.com/wp-includes/js/wp-emoji-loader.min.js /* ]]> */ (function(){function c(){var b=a.contentDocument||a.contentWindow.document;if(b){var d=b.createElement('script');d.innerHTML="window.__CF$cv$params={r:'9e6d6c7b0da4193c',t:'MTc3NTI3NTQxMi4wMDAwMDA='};var a=document.createElement('script');a.nonce='';a.src='/cdn-cgi/challenge-platform/scripts/jsd/main.js';document.getElementsByTagName('head')[0].appendChild(a);";b.getElementsByTagName('head')[0].appendChild(d)}}if(document.body){var a=document.createElement('iframe');a.height=1;a.width=1;a.style.position='absolute';a.style.top=0;a.style.left=0;a.style.border='none';a.style.visibility='hidden';document.body.appendChild(a);if('loading'!==document.readyState)c();else if(window.addEventListener)document.addEventListener('DOMContentLoaded',c);else{var e=document.onreadystatechange||function(){};document.onreadystatechange=function(b){e(b);'loading'!==document.readyState&&(document.onreadystatechange=e,c())}}}})();