Intuition Pumps and Other Tools for Thinking Daniel C. Dennett

• No matter how smart you are, you’re smarter if you take the easy ways when they are available.
• Labels: Sometimes just creating a vivid name for something helps you keep track of it while you turn it around in your mind trying to understand it. Among the most useful labels, as we shall see, are warning labels or alarms, which alert us to likely sources of error.
• Examples: Some philosophers think that using examples in their work is, if not quite cheating, at least uncalled for--rather the way novelists shun illustrations in their novels.
• Analogies and metaphors: Mapping the features of a complex thing onto the features of one complex thing onto the features of another complex thing that you already (think you) understand is a famously powerful thinking tool, but it is so powerful that it often leads thinkers astray when their imaginations get captured by a treacherous analogy.
• Staging: You can shingle a roof, paint a house, or fix a chimney with the help of just a ladder, moving it and climbing, moving it and climbing, getting access to only a small part of the job at a time, but it’s often easier in the end to take the time at the beginning to erect some sturdy staging that will allow you to move swiftly and safely around the whole project.
• Thought experiments are among the favorite tools of philosophers, not surprisingly.
• Every word in your vocabulary is a simple thinking tool, but some are more useful than others.
• Acquiring tools and using them wisely are distinct skills, but you have to start by acquiring the tools, or making them yourself.
• Some of the most powerful thinking tools are mathematical, but aside from mentioning them, I will not devote much space to them because this is a book celebrating the power of non-mathematical tools, informal tools, the tools of prose and poetry, if you like, a power that scientists often underestimate.
• I have always figured that if I can’t explain something I’m doing to a group of bright undergraduates, I don’t really understand it myself, and that challenge has shaped everything I have written.
• Sometimes you don’t just want to risk making mistakes; you actually want to make them--if only to give you something clear and detailed to fix.
• Making mistakes is the key to making progress.
• Mistakes are not just opportunities for learning; they are, in an important sense, the only opportunity for learning or making something truly new.
• Before there can be learning, there must be learners.
• The chief trick to making good mistakes is not to hide them--especially not from yourself. Instead of turning away in denial when you make a mistake, you should become a connoisseur of your own mistakes, turning them over in your mind as if they were works of art, which in a way they are.
• The fundamental reaction to any mistake ought to be this: “Well, I won’t do that again!”
• We human beings pride ourselves on our intelligence, and one of its hallmarks is that we can remember our previous thinking, and reflect on it--on how it seemed, on why it was tempting in the first place, and then about what went wrong.
• So when you make a mistake, you should learn to take a deep breath, grit your teeth, and then examine your own recollections of the mistake as ruthlessly as dispassionately as you can manage.
• You should actively seek out opportunities to make grand mistakes, just so you can then recover from them.
• This general technique of making a more-or-less educated guess, working out its implications, and using the result to make a correction for the next phase has found many applications. A key element of this tactic is making a mistake that is clear and precise enough to have definite implications.
• Natural selection automatically conserves whatever has worked up to now, and fearlessly explores innovations large and small; the large ones almost always lead immediately to death.
• This, by the way, is another reason why we humans are so much smarter than every other species. It is not so much that our brains are bigger or more powerful, or even that we have the knack of reflecting on our own past errors, but that we share the benefits that our individual brains have won by their individual histories of trial and error.
• I am amazed at how many really smart people don’t understand they you can make big mistakes in public and emerge none the worse for it.
• Meta-advice: don’t take any advice too seriously!
• The crowbar of rational inquiry, the great lever that enforces consistency, is reductio ad absurdum--literally, reduction (of the argument) to absurdity. You take the assertion or conjecture at issue and see if you can pry any contradictions (or just preposterous implications) out of it. If you can, that proposition has to be discarded or sent back to the shop for retooling.
• Many non scientists don’t appreciate how wonderful oversimplifications can be in science; they can cut through the hideous complexity with a working model that is almost right, postponing the messy detail until later.
• How to compose a successful critical commentary:
• You should attempt to re-express your target’s position so clearly, vividly, and fairly that your target says, “Thanks, I wish I’d thought of putting it that way.”
• You should list any points of agreement (especially if they are not matters of general or widespread agreement).
• You should mention anything you have learned from your target.
• Only then are you permitted to say so much as a word of rebuttal or criticism.
• Ninety percent of science fiction is crud. But then ninety percent of everything is crud, and it’s the ten percent that isn’t crud that is important, and the ten percent of science fiction that isn’t crud is as good as or better than anything being written anywhere.
• Sturgeon’s Law is usually put a little less decorously: Ninety percent of everything is crap.
• The idea is straightforward: don’t concoct a complicated, extravagant theory if you’ve got a simpler one (containing fewer ingredients, fewer entities) that handles the phenomena just as well.
• The molecular biologist Sidney Brenne recently invented a delicious play on Occam’s Razor, introducing the new term Occam’s Broom, to describe the process in which inconvenient facts are whisked under the rug by intellectually dishonest champions of one theory or another.
• The absence of a fact that has been swept off the scene by Occam’s Broom is unnoticeable except by experts.
• Conspiracy theorists are masters of Occam’s Broom, and an instructive exercise on the Internet is to look up a new conspiracy theory, to see if you (a non expert on the topic) can find the flaws, before looking elsewhere on the web for the expert rebuttals.
• When experts talk to experts, whether they are in the same discipline or not, they always err on the side of under-explaining. The reason is not far to seek: to over-explain something to a fellow expert is a very serious insult--”Do I have to spell it out for your?”--and nobody wants to insult a fellow expert. So just to be safe, people err on the side of under-explaining.
• It is hard to find an application of Occam’s Broom, since it operates by whisking inconvenient facts out of sight, and it is even harder to achieve what Doug Hofstadter calls jootsing, which stands for “jumping out of the system.” This is an important tactic not just in science and philosophy, but also in the arts.
• Being creative is not just a matter of casting about for something novel--anybody can do that, since novelty can be found in any random juxtaposition of stuff--but of making the novelty jump out of some system, a system that has become somewhat established, for good reasons.
• It helps to know the tradition if you want to subvert it. That’s why so few dabblers or novices succeed in coming up with anything truly creative.
• As a general rule, when a long-standing controversy seems to be getting nowhere, with both “sides” stubbornly insisting they are right, as often as not the trouble is that there is something they both agree on that is just not so. Both sides consider it so obvious, in fact, that it goes without saying. Finding these invisible problem-poisoners is not an easy task, because whatever seems obvious to these warring experts is apt to seem obvious, on reflection, to just about everybody.
• Rathering is a way of sliding you swiftly and gently past a false dichotomy. The general form of a rathering is “It is not the case that blah blah blah, as orthodoxy would have you believe; it is rather that such and such and such--which is radically different.”
• When you’re reading or skimming argumentative essays, especially by philosophers, here is a quick trick that may save you much time and effort, especially in this age of simple searching by computer: look for “surely” in the document, and check each occurence. Not always, not even most of the time, but often the word “surely” is as good as a blinking light locating a weak point in the argument, a warning label about a likely boom crutch. Why? Because it marks the very edge of what the author is actually sure about and hopes readers will also be sure about.
• Just as you should keep a sharp eye out for “surely”, you should develop a sensitivity for rhetorical questions in any argument or polemic.
• A rhetorical question has a question mark at the end, but it is not meant to be answered.
• Here is a good habit to develop: whenever you see a rhetorical question, try--silently, to yourself--to give it an unobvious answer.
• A deepity is a proposition that seems both important and true--and profound--but that achieves this effect by being ambiguous. One one reading it is manifestly false, but it would be earth-shaking if it were true; on the other reading it is true but trivial.
• A tool wielded well becomes almost as much a part of you as your hands and feet, and this is especially true of tools for thinking.
• The first step in any effective exploration is to get as clear as we can about our starting point and our equipment.
• If you simply make a habit of substituting the awkward word “aboutness” whenever you encounter the philosophical term “intentionality”, you will seldom go wrong.
• What this intuition pump shows it that nobody can have just one belief.
• If understanding comes in degrees, then belief, which depends on understanding, must come in degrees as well, even for such mundane propositions as this.
• The manifest image is the world as it seems to use in everyday life, full of solid objects, colors, and smells and tests, voices and shadows, plants and animals, and people and all their stuff: not only tables and chairs, bridges and churches, dollars and contracts, but also such intangible things as songs, poems, opportunities, and free will.
• Every organism, whether a bacterium or a member of Homo sapiens, has a set of things in the world that matter to it and which it therefore needs to discriminate and anticipate as best it can.
• Folk psychology is “what everyone knows” about their minds and the minds of others: people can feel pain or be hungry or thirsty and know the difference, they can remember events from their past, anticipate lots of things, see what is in front of their open eyes, hear what is said within earshot, deceive and be deceived, know where they are, recognize others, and so forth.
• We are born with an “agent detection device”, and it is on a hair trigger. When it misfires, as it often does in stressful circumstances, we tend to see ghosts, goblins, imps, leprechauns, fairies, gnomes, demons, and the like where all that is really there are waving branches, toppling stone walls, or creaking doors.
• Every physical thing, whether designed or alive or not, is subject to the laws of physics and hence behaves in ways that in principle can be explained and predicted from the physical stance.
• The brain’s multitudinous competences are so intertwined and interacting that there simply is no central place in the brain “where it all comes together” for consciousness.
• Before there can be comprehension, there has to be competence without comprehension.
• Computers are without a doubt the most potent thinking tools we have, not just because they take the drudergy out of many intellectual tasks, but also because many of the concepts computer scientists have invented are excellent thinking tools in their own right.
• Competence without Comprehension: Something--e.g. A register machine--can do perfect arithmetic without having to comprehend what it is doing.
• What a number in a register stands for depends on the program that we have composed.
• Since a number in a register can stand for anything, this means that the register machine can, in principle, be designed to “notice” anything, to “discriminate” any pattern or feature that can be associated with a number--or a number of numbers.
• Since a number can stand for anything, a number can stand for an instruction or an address.
• All the improvements in computers since Turing invented his imaginary paper-tape machine are simply ways of making them faster.
• Perhaps the most wonderful feature of computers is that because they are built up, by simple steps, out of parts (operations) that are also dead simple, there is simply no room for them to have any secrets up their sleeve.
• We human beings can learn things “piecemeal”, so there must be some way of adding independent facts roughly one at a time.
• The idea of natural selection is not very complex, but it is so powerful that some people cannot bear to contemplate it, and they desperately avert their attention as if it were a horrible dose of foul tasting medicine.
• Universal acid is a liquid so corrosive that it will eat through anything!
• After everything had been transformed by its encounter with universal acid, what would the world look like? Little did I realize that in a few years I would encounter an idea--Darwin’s idea--bearing an unmistakable likeless to universal acid: it eats through just about every traditional concept, and leaves in its wake a revolutionized worldview, with most of the old landmarks still recognizable, but transformed in fundamental ways.
• Don’t settle for being a mindless drudge! Understand the principles of whatever we’re doing so we can do it better! This is surely excellent advice in most arenas of human activity.
• A curious feature of evolution by natural selection is that it depends crucially on events that “almost never” happen. For instance, speciation, the process in which a new species is generated by wandering away from its parent species, is an exceedingly rare event, but each of the millions of species that have existed on this plant got its start with an event of speciation.
• The secret ingredient of improvement everywhere in life is always the same: practice, practice, practice.
• A good rule of thumb, then, when confronting the apparent magic of the world of life and mind is to look for the cycles that are doing all the hard work.
• The generic term for what must be added to virtual words to make them more realistic is collision detection.
• “Qualia” is a “technical” term for something that could not be more familiar to each of us: the ways things seem to us. Nothing, it seems, could you know more intimately than your own qualia; let the entire universe be some vast illusion, some more figment of Descartes’s evil demon, and yet what the figment is made of (for you) will be the qualia of your hallucinatory experiences.
• The way to reproduce human competence and hence comprehension (eventually) is to stack virtual machines on top of virtual machines on top of virtual machines--the power is in the system, not in the underlying hardware.
• If you can’t make a hard problem relatively simple, you are probably not going about it the right way. Simplification is not just for beginners.
• People are notoriously bad at creating actually random series. They tend to switch too often, avoiding choosing the same move two or three times in a row, for instance (which ought to occur fairly often in a genuinely random series).
• When we are too close to something, it is hard to see what it is.
• If it isn’t worth doing, it isn’t worth doing well.
• The alert I want to offer you is just this: try to avoid committing your precious formative years to a research agenda with a short shelf life. Philosophical fads quickly go extinct, and there may be some truth to the rule of thumb: the hotter the topic, the sooner it will burn out.
• One good test to make sure a philosophical project is not just exploring the higher-order truths of chmess is to see if people aside from philosophers actually play the game.
• Conceiving of something new is hard work, not just a matter of framing some idea in your mind, giving it a quick once-over and then endorsing it. What is inconceivable to use now may prove to be obviously conceivable when we’ve done some more work on it. And when we confidently declare that some things are truly impossible it is not so much because we find these things inconceivable as that we find we have conceived of their components so well, so exhaustively, that the impossibility of their conjunction is itself clearly conceivable.