Turing Award Laureates

"Have you considered perceptrons with many layers? ... We have not found (by thinking or by studying the literature) any other really interesting class of multilayered machine, at least none whose principles seem to have a significant relation to those of the perceptron. To see the force of this qualification it is worth pondering the fact, trivial in itself, that a universal computer could be built entirely out of linear threshold modules. This does not in any sense reduce the theory of computation and programming to the theory of per­ceptrons."

"[We] became involved with a somewhat therapeutic compulsion: to dispel what we feared to be the first shadows of a “holistic” or “Gestalt” misconception that would threaten to haunt the fields of engineering and artificial intelligence as it had earlier haunted biology and psychology. For this, and for a variety of more practical and theoretical goals, we set out to find something about the range and limitations of perceptrons."

"We do not see that any good can come of experiments which pay no attention to limiting factors that will assert themselves as soon as the small model is scaled up to a usable size."

"Perceptrons have been widely publicized as “pattern recognition” or “learning” machines and as such have been discussed in a large number of books, journal articles, and voluminous “reports.” Most of this writing...is without scientific value."

"One popular version is that the publication of our book so discouraged research on learning in network machines that a promising line of research was interrupted. Our version is that progress had already come to a virtual halt because of the lack of adequate basic theories... Most theorists had tried to focus only on the mathematical structure of what was common to all learning, and the theories to which this had led were too general and too weak to explain which patterns perceptrons could learn to recognize... The trouble appeared when perceptrons had no way to represent the knowledge required for solving certain problems. The moral was that one simply cannot learn enough by studying learning by itself; one also has to understand the nature of what one wants to learn."

"What magical trick makes us intelligent? The trick is that there is no trick. The power of intelligence stems from our vast diversity, not from any single, perfect principle."

"For generations, scientists and philosophers have tried to explain ordinary reasoning in terms of logical principles — with virtually no success. I suspect this enterprise failed because it was looking in the wrong direction: common sense works so well not because it is an approximation of logic; logic is only a small part of our great accumulation of different, useful ways to chain things together."

"We rarely recognize how wonderful it is that a person can traverse an entire lifetime without making a single really serious mistake — like putting a fork in one's eye or using a window instead of a door."

"One's present personality cannot share all the thoughts of one's older personalities — and yet it has some sense that they exist. This is one reason why we feel that we possess an inner Self — a sort of ever-present person-friend, inside the mind, whom we can always ask for help."

"Questions about arts, traits, and styles of life are actually quite technical. They ask us to explain what happens among the agents of our minds. But this is a subject about which we have never learned very much... Such questions will be answered in time. But it will just prolong the wait if we keep using pseudo-explanation words like "holistic" and "gestalt." …It's harmful, when naming leads the mind to think that names alone bring meaning close."

"The "laws of thought" depend not only on the property of brain cells, but also on how they are connected. And these connections are established not by the basic, "general" laws of physics... To be sure, "general" laws apply to everything. But, for that very reason, they can rarely explain anything in particular. ...Each higher level of description must add to our knowledge about lower levels."

"How many processes are going on, to keep that teacup level in your grasp? There must be a hundred of them."

"Unless we can explain the mind in terms of things that have no thoughts or feelings of their own, we'll only have gone around in a circle."

"This book... too, is a society — of many small ideas. Each by itself is only common sense, yet when we join enough of them we explain the strangest mysteries of mind."

"We'll show you that you can build a mind from many little parts, each mindless by itself."

"When no idea seems right, the right one must seem wrong."

"Innate sentic detectors could help by teaching children about their own affective states. For if distinct signals arouse specific states, the child can associate those signals with those states. Just knowing that such states exist, that is, having symbols for them, is half the battle."

"How do both music and vision build things in our minds? Eye motions show us real objects; phrases show us musical objects. We "learn" a room with bodily motions; large musical sections show us musical "places." Walks and climbs move us from room to room; so do transitions between musical sections. Looking back in vision is like recapitulation in music; both give us time, at certain points, to reconfirm or change our conceptions of the whole."

"Our eyes are always flashing sudden flicks of different pictures to our brains, yet none of that saccadic action leads to any sense of change or motion in the world; each thing reposes calmly in its "place"! ...What makes us such innate Copernicans?"

"Hearing music is like viewing scenery and... when we hear good music our minds react in very much the same way they do when we see things."

"Music... immerses us in seemingly stable worlds! How can this be, when there is so little of it present at each moment?"

"Theorems often tell us complex truths about the simple things, but only rarely tell us simple truths about the complex ones. To believe otherwise is wishful thinking or "mathematics envy.""

"Perhaps the music that some call 'background' music can tranquilize by turning under-thoughts from bad to neutral, leaving the surface thoughts free of affect by diverting the unconscious."

"Most adults have some childlike fascination for making and arranging larger structures out of smaller ones."

"The way the mathematics game is played, most variations lie outside the rules, while music can insist on perfect canon or tolerate a casual accompaniment."

"Of what use is musical knowledge? Here is one idea. Each child spends endless days in curious ways; we call this play. A child stacks and packs all kinds of blocks and boxes, lines them up, and knocks them down. … Clearly, the child is learning about space! ...how on earth does one learn about time? Can one time fit inside another? Can two of them go side by side? In music, we find out!"

"Each subsociety of mind must have its own internal epistemology and phenomenology, with most details private, not only from the central processes, but from one another."

"Most theories of learning have been based on ideas of "reinforcement" of success. But all these theories postulate a single, centralized reward mechanism. I doubt this could suffice for human learning because the recognition of which events should be considered memorable cannot be a single, uniform process. It requires too much "intelligence." Instead I think such recognitions must be made, for each division of the mind, by some other agency that has engaged the present one for a purpose."

"It would seem that making unusual connections is unusually difficult and, often, rather "indirect"—be it via words, images, or whatever. The bizarre structures used by mnemonist (and, presumably unknowingly, by each of us) suggests that arbitrary connections require devious pathways."

"A memory should induce a state through which we see current reality as an instance of the remembered event — or equivalently, see the past as an instance of the present. ...the system can perform a computation analogous to one from the memorable past, but sensitive to present goals and circumstances."

"Changing the states of many agents grossly alters behavior, while changing only a few just perturbs the overall disposition a little."

"Get the mind into the (partial) state that solved the old problem; then it might handle the new problem in the "same way.""

"Old answers never perfectly suit new questions, except in the most formal, logical circumstances."

"I maintain that attitudes do really precede propositions, feelings come before facts."

"Concrete concepts are not necessarily the simplest ones. A novice best remembers "being at" a concert. The amateur remembers more of what it "sounded like." Only the professional remembers the music itself, timbres, tones and textures."

"We shall envision the mind (or brain) as composed of many partially autonomous "agents"—as a "Society" of smaller minds. ...It is easiest to think about partial states that constrain only agents within a single Division. ...(we suggest) the local mechanisms for resolving conflicts could be the precursors of what we know later as reasoning — useful ways to combine different fragments of knowledge."

"We usually say that one must first understand simpler things. But what if feelings and viewpoints are the simpler things?"

"When you "get an idea," or "solve a problem," or have a "memorable experience," you create what we shall call a K-line. This K-line gets connected to those "mental agencies" that were actively involved in the memorable event. When that K-line is later "activated," it reactivates some of those mental agencies, creating a "partial mental state" resembling the original."

"Positive general principles need always to be supplemented by negative, anecdotal censors. For, it hardly ever pays to alter a general mechanism to correct a particular bug."

"All intelligent persons also possess some larger-scale frame-systems whose members seemed at first impossibly different — like water with electricity, or poetry with music. Yet many such analogies — along with the knowledge of how to apply them — are among our most powerful tools of thought. They explain our ability sometimes to see one thing — or idea — as though it were another, and thus to apply knowledge and experience gathered in one domain to solve problems in another. It is thus that we transfer knowledge via the paradigms of Science. We learn to see gases and fluids as particles, particles as waves, and waves as envelopes of growing spheres."

"For avoiding nonsense in general, we might accumulate millions of censors. For all we know, this "negative meta-knowledge" — about patterns of thought and inference that have been found defective or harmful — may be a large portion of all we know."

"Questioning one's own "top-level" goals always reveals the paradox-oscillation of ultimate purpose. How could one decide that a goal is worthwhile — unless one already knew what it is that is worthwhile?"

"Since we have no systematic way to avoid all the inconsistencies of commonsense logic, each person must find his own way by building a private collection of "cognitive censors" to suppress the kinds of mistakes he has discovered in the past."

"I am inclined to doubt that anything very resembling formal logic could be a good model for human reasoning. In particular, I doubt that any logic that prohibits self-reference can be adequate for psychology: no mind can have enough power — without the power to think about Thinking itself. Without Self-Reference it would seem immeasurably harder to achieve Self-Consciousness — which, so far as I can see, requires at least some capacity to reflect on what it does. If Russell shattered our hopes for making a completely reliable version of commonsense reasoning, still we can try to find the islands of "local consistency," in which naive reasoning remains correct."

"If there's something you like very much then you should regard this not as you feeling good but as a kind of brain cancer, because it means that some small part of your mind has figured out how to turn off all the other things."

"If you like somebody's work -- just go and see them. However, don't ask for their autograph. A lot of people came and asked me for my autograph -- and it's creepy. What I did is read everything they published first... and correct them. That's what they really want. Every smart person wants to be corrected, not admired."

"You don't understand anything until you learn it more than one way."

"An ethicist is someone who sees something wrong with whatever you have in mind."

"When David Marr at MIT moved into computer vision, he generated a lot of excitement, but he hit up against the problem of knowledge representation; he had no good representations for knowledge in his vision systems."

"Will robots inherit the earth? Yes, but they will be our children."