All Quotes

"For some purposes we might use machines (choice... or c-machines) whose motion is only partially determined by the configuration... When such a machine reaches... ambiguous configurations, it cannot go on until some arbitrary choice has been made by an external operator. This would be the case if we were using machines to deal with axiomatic systems."

"In this paper I deal only with automatic machines, and will therefore often omit the prefix ɑ-."

"If an ɑ-machine prints two kinds of symbols, of which the first kind (called figures) consists entirely of 0 and 1 (the others being called symbols of the second kind), then the machine will be called a computing machine."

"It will be useful to put... tables into a... standard form. ...The lines of the table are... of form m-config. | Symbol | Operations | Final m-config. In this way we obtain a complete description of the machine. ...This new description of the machine may be called the standard description (S.D). ...[W]e shall have a description of the machine in the form of an arabic numeral. The integer represented by this numeral may be called a description number (D.N) of the machine. The D.N determine the S.D and the structure of the machine uniquely. The machine whose D.N is n may be described as \mathcal{M}(n)."

"To each computable sequence there corresponds at least one description number, while to no description number does there correspond more than one computable sequence. The computable sequences and numbers are therefore enumerable."

"It is possible to invent a single machine which can be used to compute any computable sequence. If this machine \mathcal{U} is supplied with a tape on the beginning of which is written the S.D of some computing machine \mathcal{M}, then \mathcal{U} will compute the same sequence as \mathcal{M}."

"Can machines think?"... The new form of the problem can be described in terms of a game which we call the 'imitation game." It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart from the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either "X is A and Y is B" or "X is B and Y is A." The interrogator is allowed to put questions to A and B... We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?"

"We do not wish to penalise the machine for its inability to shine in beauty competitions, nor to penalise a man for losing in a race against an aeroplane. The conditions of our game make these disabilities irrelevant."

"May not machines carry out something which ought to be described as thinking but which is very different from what a man does?"

"We are not asking whether all digital computers would do well in the game nor whether the computers at present available would do well, but whether there are imaginable computers which would do well."

"The idea behind digital computers may be explained by saying that these machines are intended to carry out any operations which could be done by a human computer."

"I would give great praise to the physician whose mistakes are small, for perfect accuracy is seldom to be seen, since many physicians seem to me to be in the same plight as bad pilots, who, if they commit mistakes while conducting the ship in a calm do not expose themselves, but when a storm and violent hurricane overtake them, they then, from their ignorance and mistakes, are discovered to be what they are, by all men, namely, in losing their ship."

"Mild success can be explainable by skills and labor. Wild success is attributable to variance."

"[N]o less mischief happens to a man from unseasonable depletion than from repletion... to the bulk of mankind it is of little consequence which of these rules they observe... whether they make it a practice to take one or two meals [per day]. But there are certain persons who cannot readily change their diet with impunity; and if they make any alteration in it for one day, or even for a part of a day, are greatly injured thereby."

"[W]e ought not to reject the ancient Art, as if it were not, and had not been properly founded, because it did not attain accuracy in all things, but rather, since it is capable of reaching to the greatest exactitude by reasoning, to receive it and admire its discoveries, made from a state of great ignorance, and as having been well and properly made, and not from chance."

"[O]f articles of food, those which are unsuitable and hurtful to man when administered, every one is either bitter... or saltish or acid, or something else intense and strong, and therefore we are disordered by them... But all those things of which a man eats and drinks are devoid of any such intense and well-marked quality... which man is accustomed to use for food, with the exception of condiments and confectionaries, which are made to gratify the palate and for luxury. And from those things, when received into the body abundantly, there is no disorder nor dissolution of the powers belonging to the body; but strength, growth, and nourishment... for no other reason than because they are well mixed, have no thing in them of an immoderate character, nor anything strong, but the whole forms... [of] simple and not strong substance."

"Certain s and physicians say that it is not possible for any one to know medicine who does not know what man is, and that who ever would cure men properly, must learn this in the first place. But this saying rather appertains to philosophy, as Empedocles and certain others have described what man in his origin is, and how he first was made and constructed. But I think whatever such has been said or written by sophist or physician concerning nature has less connexion with the art of medicine than with the art of painting. And I think that one cannot know anything certain respecting nature from any other quarter than from medicine... Wherefore it appears to me necessary to every physician to be skilled in nature, and strive to know... what man is in relation to the articles of food and drink, and to his other occupations, and what are the effects of each of them to every one."

"Let food be thy medicine and medicine be thy food."

"Walking is man's best medicine."

"Both Plato and Aristotle approved of abortion, the former in the interests of wise population policy, the latter chiefly on the ground that it was an element of the family’s proper freedom in the state. Hippocrates’ words on the subject are, in the original Greek, somewhat less blunt and categorical than modern takers of the Hippocratic Oath have sometimes suggested. All Hippocrates says is: “I will not give to a woman a pessary to produce abortion.” There were other means of abortion known to the Greeks, none of which Hippocrates abjures."

"The Pythagoreans, rather than Hippocrates himself, are believed to have been responsible for the passage in the Hippocratic Oath that prohibits assisting a woman to bring about an abortion: “I will give no deadly medicine to anyone if asked, not suggest any such counsel; and in like manner I will not give a woman a remedy to produce abortion.” The doubt about whether Hipporates actually wrote the prohibition on abortion in the oath attributed to him is due to the fact that Hippocrates (c. 460-377 B.C.E.) believed that fetuses became animated, not at conception, but on thirtieth day of gestation for male fetuses and the forty-second day for females."

"The Christian church father Tertullian accused Hippocrates of possessing one of the brutal instruments designed to dismember a fetus in a breech birth. Although no surviving Hippocratic treatise has instructions on this procedure, it was performed in those years to save the life of the mother. One Hippocratic work, Nature of the Child, describes the procedure of abortion by manipulation called Lacedamonian leap in the case of a six-day-old-embryo: “jump up and down, touching her buttocks with her heels at each leap [for] . . . seven times”; after this, “there was a noise; the seed fell out on the ground” . . . “as though someone had removed the shell from a raw egg.”"

"My major hobby is teasing people who take themselves and the quality of their knowledge too seriously and those who don’t have the guts to sometimes say: I don’t know...."

"You may not be able to change the world but can at least get some entertainment and make a living out of the epistemic arrogance of the human race."

"It is now the scientific consensus that our risk-avoidance mechanism is not mediated by the cognitive modules of our brain, but rather by the emotional ones. This may have made us fit for the Pleistocene era. Our risk machinery is designed to run away from tigers; it is not designed for the information-laden modern world."

"Much of the research into humans' risk-avoidance machinery shows that it is antiquated and unfit for the modern world; it is made to counter repeatable attacks and learn from specifics. If someone narrowly escapes being eaten by a tiger in a certain cave, then he learns to avoid that cave."

"We should reward people, not ridicule them, for thinking the impossible."

"Delivering advice assumes that our cognitive apparatus rather than our emotional machinery exerts some meaningful control over our actions."

"It does not matter how frequently something succeeds if failure is too costly to bear."

"Trading forces someone to think hard; those who merely work hard generally lose their focus and intellectual energy. In addition, they end up drowning in randomness; work ethics draw people to focus on noise rather than the signal."

"Lucky fools do not bear the slightest suspicion that they may be lucky fools - by definition, they do not know that they belong to such a category."

"Unlike a well-defined, precise game like Russian roulette, where the risks are visible to anyone capable of multiplying and dividing by six, one does not observe the barrel of reality."

"[T]he epic poet did not judge heroes by the result... their fate depended on totally external forces... Heroes are heroes because they are heroic in behavior, not because they won or lost."

"Mixing forecast and prophecy is symptomatic of randomness-foolishness..."

"I do not dispute that arguments should be simplified to their maximum... but people often confuse complex ideas that cannot be simplified into a media-friendly statement as symptomatic of a confused mind. ...MBAs tend to blow up in financial markets, as they are trained to simplify... beyond... requirement. (...I am myself the unhappy holder of the degree.)"

"[T]he mental probabilistic map in one's mind is so geared toward the sensational that one would realize informational gains by dispensing with the news."

"From the standpoint of an institution, the existence of a risk manager has less to do with actual risk reduction than it has to do with the impression of risk reduction."

"In the early 1990s... I became addicted to the various Monte Carlo engines, which I taught myself to build... The dividend of the computer revolution... did not come in... e-mail messages and... chat rooms; it was in the sudden availability of fast processors capable of generating a million sample paths per minute."

"My models showed that ultimately almost nobody really survived; bears dropped like flies in the rally and bulls ended up being slaughtered... But there was one exception... option buyers... could buy the insurance against blowup..."

"I have two ways of learning from history: from the past, by reading the elders; and from the future, thanks to my Monte Carlo toy."

"A... vicious effect of... is that those that are good at predicting the past... think of themselves as good at predicting the future... [W]e live in a world where important events are not predictable..."

"[H]istory cannot lend itself to experimentation. But... is potent enough... to eventually bury the bad guy. Bad trades catch up with you... Mathematicians of probability give that a... name: '. [R]oughly... properties of a very... long sample path would be similar to the Monte Carlo properties of an average of shorter ones. ...Those unlucky... in spite of their skills would eventually rise. The lucky fool... would slowly converge to the state of a less-lucky idiot. Each ...would revert to his long-term properties."

"[A]ge is beauty. ...[M]y instinct is to value distilled thought over newer thinking, regardless of its apparent sophistication—another reason to accumulate the hoary volumes by my bedside... For an idea to have survived so many cycles is indicative of its relative fitness. Noise, at least some noise, was filtered out. ...[P]rogress means that some new information is better than past information, not that the average of new information will supplant past information..."

"There are hordes of thoughtful journalists... [I]t is just that prominent media journalism is a thoughtless process of providing the noise that captures people's attention and there exists no mechanism for separating the two."

"I... found a significant advantage in selecting aged traders, using as a selection criterion their cumulative years of experience rather than their absolute success... [O]lder people have been exposed longer to the rare event and can be, convincingly, more resistant to it."

"Over a short time increment, one observes the variability of the portfolio, not the returns. ...[O]ne sees the variance, little else. ...Our emotions are not designed to understand the point. ...I deal with it by having no access to information. ...I prefer to read poetry."

"[N]ews... is full of noise and... history is largely stripped of it."

"A trader's mental construction should direct him to do precisely what other people do not do."

"Veteran trader Marty O'Connell calls this the firehouse effect. ...[F]iremen ...who talk to each other for too long come to agree on many things that an outside, impartial observer would find ludicrous..."

"[A]t any point in time, the richest traders are often the worst traders. This I will call the cross-sectional problem: At a given time... the most successful traders are likely to be those fit for the latest cycle."