(Disclaimer/TL;DR: This article, much like Camelot, is a silly place/post. Nonetheless I think it presents a pretty solid list of 10 rationality lessons to take away from Less Wrong which must not be forgotten upon pain of eternal damnation/irrationality.)
In a realm not far from here, somewhere within a bustling metropolis, there lies an old and dusty book. It is placed in a most conspicuous location; in the middle of a busy street where countless citizens walk by it every day. Yet none pick it up, for it is placed on a pedestal just high enough that it cannot be reached or seen easily, and the slight inconvenience of standing on one’s toes to reach for it is sufficient to deter most. Yet if a traveller were sufficiently aware to look up and see the book, and curious enough to reach for it, and willing to suffer the slight discomfort of having to touch its muddy cover to open and read its ancient pages, that one would find within a wealth of wisdom and rationality that would transform the reader’s life forever. For this is the most holy Book of Bayes, and its first and last pages both read thusly:
The Ten Commandments of Rationality
1) Thou shalt never conflate the truth or falsehood of a proposition with any other characteristic, be it the consequences of the proposition if it be true, or the consequences of believing it for thyself personally, or the pleasing or unpleasant aesthetics of the belief itself. Furthermore, thou shalt never let thy feelings regarding the matter overrule what thy critical faculties tells thee, or in any other way act as if reality might adjust itself in accordance with thine own wishes.
2) Thou shalt not accept any imperfect situation if it may be optimized, nor shalt thou abstain from improving upon a situation by imagining ever better options without acting on any of them, nor must thee allow thyself to be paralyzed with fear or apathy or indecision when any action is still superior to doing nothing at all. Thus let it be said: Thou shalt not allow thyself to be beaten by a random number generator.
3) Thou shalt not declare any matter to be unscientific, or inherently irrational, or a false question, or with any other excuse wilfully close thine own eyes and expel all curiosity regarding the matter before thou hast even asked thyself whether the question is worth answering. To transgress thusly is to forfeit any chance to update thy own beliefs on a matter that is truly unusual to thee.
4) Thou shalt not hold goals or beliefs which conflict with each other, in such a manner as to violate most divine transitivity, and thereby set thyself up for most ignominious defeat, and rest easy in knowing this fact. Rather shalt thou engage in mindfulness and self-reflection, and in doing so find thy own true priorities, and solve any inconsistencies in a utility maximising manner so that thou may not fall prey to the wrath of the most holy Dutch Book, which is merciless but just.
5) Thou shalt never engage in defeatism, nor wallow in ennui or existential angst, or in any other way declare that thy efforts are pointless and that exerting thyself is entirely without merit. For just as it is true that matters may never get to the point where they cannot possibly get any worse, so is it true that no situation is impossible to improve upon.
6) Thou shalt never judge a real or proposed action by any metric other than this: The expected consequences of the action, both direct and indirect, be they subtle or blatant, taking into account all relevant information available at the time of deciding and no more or less than this.
7) Thou shalt never sit back on thy lazy laurels and wait for rationality to come to thee, nor shalt thou declare that thy beliefs must be correct as all others have failed to convince thee of the contrary: The cultivation of thy rationality and the falsification of thine beliefs is thine own most sacred task, which is eternal and never finished, and to leave it to others is to invite doom upon the validity of thine own beliefs and actions, for in this case others will never serve thee as well as thou might serve thyself.
8) Thou shalt never let argumentation stand in the way of knowledge, nor let knowledge stand in the way of wisdom, nor let wisdom stand in the way of victory, no matter how wise or clever it makes thee feel. Also shalt thou never conflate exceptions for rules or rules for exceptions when arguing any issue, nor bring up minutiae as if they were crucial issues, nor allow oneself to be swept away in arguing for the sake of argumentation, nor act to score cheap and yea also easy points, nor present thy learnings in a needlessly ambiguous manner such as this if it can be helped, or in any other way allow oneself to lose sight of thine most sacred goal, which is victory.
9) Thou shalt never assign a probability exactly equal to 0 or 1 to any proposition, nor declare to the skies that thy certainty regarding any matter is absolute, nor any derivation of such, for to do so is to declare thyself infallible and is placing thyself above thine most holy lord, Bayes.
10) Thou shalt never curse thy rationality, and wish for ye immediate satisfaction over thy eventual victory, all for the sake of base emotion, which is transient whereas victory is transcendent. Let it be known that it is an unspoken truth amongst rationalists -indeed it is the first and most elementary rule of rationality and yet oft forgotten by those practiced in the art- that base impulse and most holy reason are as a general rule incompatible, as there cannot be two skies.
Such are the Ten Commandments of Rationality. And Lo! If one abides by these rules, then let it be said that they act virtuously, and the heavens shall reward them with the splendour of higher expected utility relative to the counterfactual wherein they did not act virtuously. But to those who do not act virtuously, but rather act with irrationality in their minds and biases in their thinking, and who in doing so break any of the Commandments of Rationality, to them let it be said that they have transgressed against thy lord Bayes, and they shall be smitten by the twin gods of Cause and yea also Effect as surely as if they had smitten themselves. For let it be said: The gods of causality may be blind, but their aim doth be excellent regardless.
(All silliness aside, what do you all think? Is this a good list of 10 things to take away from Less Wrong? Do you have a better list? Are posts like these a waste of time? Or, Bayes forbid, did I get my thees and thous wrong somewhere? Let me know in the comments.)