The Universe of Discourse

Mon, 20 Mar 2006

The 20 most important tools
Forbes magazine recently ran an article on The 20 Most Important Tools. I always groan when I hear that some big magazine has done something like that, because I know what kind of dumbass mistake they are going to make: they are going to put Post-It notes at #14. The Forbes folks did not make this mistake. None of their 20 items were complete losers.

In fact, I think they did a pretty good job. They assembled a panel of experts, including Don Norman and Henry Petroski; they also polled their readers and their senior editors. The final list isn't the one I would have written, but I don't claim that it's worse than one I would have written.

Criticizing such a list is easy—too easy. To make the rules fair, it's not enough to identify items that I think should have been included. I must identify items that I think nearly everyone would agree should have been included.

Unfortunately, I think there are several of these.

First, to the good points of the list. It doesn't contain any major clinkers. And it does cover many vitally important tools. It provokes thought, which is never a bad thing. It was assembled thoughtfully, so one is not tempted to dismiss any item without first carefully considering why it is in there.

Here's the Forbes list:

  1. The Knife
  2. The Abacus
  3. The Compass
  4. The Pencil
  5. The Harness
  6. The Scythe
  7. The Rifle
  8. The Sword
  9. Eyeglasses
  10. The Saw
  11. The Watch
  12. The Lathe
  13. The Needle
  14. The Candle
  15. The Scale
  16. The Pot
  17. The Telescope
  18. The Level
  19. The Fish Hook
  20. The Chisel
The Forbes list has some restrictions. "Tools" must be simple, portable physical implements. Fundamental machines are omitted; most notably, this excludes "the lever" and "the wheel". (The invention of real importance there is not the wheel, but the axle. But that's another article for another time.) Inventions like fire, glassblowing, the computer, gunpowder, the windmill, and written language are ruled out, not because they are unimportant, but because they are not "tools" in the sense of being fairly simple, portable physical implements. They belong on some list, but not this one. (That didn't stop Don Norman from writing a ponderous and obvious essay about how the Forbes list was the wrong list to make. I know Don Norman has his fans, but I've never understood why.)


The Forbes items are also allowed to stand for categories. For example, "the Rifle" really stands for portable firearms, including muskets and such. "The pencil" includes pens and writing brushes. (Why put "the pencil" and not "the pen"? I imagine Henry Petroski arguing about it until everyone else got tired and gave up.) The spoon, had they included it, would have stood for eating utensils in general.

But here is my first quibble: it's not really clear why some items stood for whole groups, and others didn't. The explanatory material points out that five other items on the list are special cases of the knife: the scythe, lathe, saw, chisel, and sword. The inclusion of the knife as #1 on the list is, I think, completely inarguable. The power and the antiquity of the knife would put it in the top twenty already.

Consider its unmatched versatility as well and you just push it up into first place, and beyond. Make a big knife, and you have a machete; bigger still, and you have a sword. Put a knife on the end of a stick and you have an axe; put it on a longer stick and you have a spear. Bend a knife into a circle and you have a sickle; make a bigger sickle and you have a scythe. Put two knives on a hinge or a spring and you have shears. Any of these could be argued to be in the top twenty. When you consider that all these tools are minor variations on the same device, you inevitably come to the conclusion that the knife is a tool that, like Babe Ruth among baseball players, is ridiculously overqualified even for inclusion with the greatest.

But Forbes people gave the sword a separate listing (#8), and a sword is just a big knife. It serves the same function as a knife and it serves it in the same mechanical way. So it's hard to understand why the Forbes people listed them separately. If you're going to list the sword separately, how can you omit the axe or the spear? Grouping the items is a good idea, because otherwise the list starts to look like the twenty most important ways to use a knife. But I would have argued for listing the sword, axe, chisel, and scythe under the heading of "knife".

I find the other knifelike devices less objectionable. The saw is fundamentally different from a knife, because it is made and used differently, and operates in a different way: it is many tiny knives all working in the same direction. And the lathe is not a special case of the knife, because the essential feature of the lathe is not the sharp part but the spinning part. (I wouldn't consider the lathe a small, portable implement, but more about that below.)


I said that I was required to identify items that everyone would agree are major omissions. I have two such criticisms. One is that the list has room for six cutting tools, but no pounding tools. Where is the club? Where is the hammer? I could write a whole article about the absurdity of omitting the hammer. It's like leaving Abraham Lincoln off of a list of the twenty greatest U.S. presidents. It's like leaving Albert Einstein off of a list of the twenty greatest scientists. It's like leaving Honus Wagner off of a list of the twenty greatest baseball players.

No, I take it back. It's not like any of those things. Those things should all be described as analogous to leaving the hammer of the list of the twenty most important tools, not the other way around.

Was the hammer omitted because it's not a simple, portable physical implement? Clearly not.

Was the hammer omitted because it's an abstract fundamental machine, like the lever? Is a hammer really just a lever? Not unless a knife is just a wedge.

Is the hammer subsumed in one of the other items? I can't see any candidates. None of the other items is for pounding.

Did the Forbes panel just forget about it? That would have been weird enough. Two thousand Forbes readers, ten editors, and Henry Petroski all forgot about the hammer? Impossible. If you stop someone on the street and ask them to name a tool, odds are that they will say "hammer". And how can you make a list of the twenty most important tools, include the chisel as #20, and omit the hammer, without which the chisel is completely useless?

The article says:

We eventually came up with a list of more than 100 candidate tools. There was a great deal of overlap, so we collapsed similar items into a single category, and chose one tool to represent them. That left us with a final list of 33 items, each one a part of a particular class or style of tool; for instance, the spoon is representative of all eating utensils.

Perhaps the hammer was one of the 13 classes of tools that didn't make the cut? The writer of the article, David M. Ewalt, kindly provided me with a complete list of the 33 classes, including the also-rans. The hammer was not with the also-rans; I'm not sure if I find that more or less disturbing.


Well, enough about hammers. The 13 classes that did not make the cut were:

  • spoon
  • longbow
  • broom
  • paper clip
  • computer mouse
  • floppy disk
  • syringe
  • toothbrush
  • barometer
  • corkscrew
  • gas chromatograph
  • condom
  • remote control
Presumably some of these would have been cleaned up for publication, had they been selected for the top 20. For example, "longbow" should obviously be "bow". So I don't want to criticize these too much. The omissions seem more striking to me than the inclusions. But some of the inclusions are just too strange to let pass without comment, and some of those comments will help us understand what should be on the list and what shouldn't be.

"Gas chromatograph" seems to be someone's attempt to steer the list away from ancient inventions and to include some modern tools on the list. This is a worthy purpose. But I wish that they had thought of a better representative than the gas chromatograph. It seems to me that most tools of modern invention serve only very specialized purposes. The gas chromatograph is not an exception. I've never used a gas chromatograph. I don't think I know anyone who has. I've never seen a gas chromatograph. I might well go to the grave without using one. How is it possible that the gas chromatograph is one of the 33 most important tools of all time, beating out the hammer?

With "syringe", I imagine the authors were thinking of the hypodermic needle, but maybe they really were thinking of the syringe in general, which would include the meat syringe, the vacuum pipette, and other similar devices. If the latter, I have no serious complaint; I just wanted to point out the possible misunderstanding.

"Paper clip" is just the kind of thing I was afraid would appear. The paper clip isn't one of the top hundred most important tools, perhaps not even one of the top thousand. If the hammer were annihilated, civilization would collapse within twenty-four hours. If the paper clip were annihilated, we would shrug, we would go back to using pins, staples, and ribbons to bind our papers, and life would go on. If the pin isn't qualified for the list, the paper clip isn't even close.

I was speechless at the inclusion of the corkscrew in a list of essential tools that omits both bottles and corks, reduced to incoherent spluttering. The best I could do was mutter "insane".

I don't know exactly what was intended by "remote control", but it doesn't satisfy the criteria. The idea of remote control is certainly important, but this is not a list of important ideas or important functions but important tools. If there were a truly universal remote control that I could carry around with me everywhere and use to open doors, extinguish lights, summon vehicles, and so on, I might agree. But each particular remote control is too specialized to be of any major value.

Putting the computer mouse on the list of the twenty (or even 33) most important tools is like putting the pastrami on rye on the list of the twenty most important foods. Tasty, yes. Important? Surely not. In the same class as the soybean? Absurd.

The floppy disk is already obsolete.

Other comparisons

The telescope

Returning to the main list, eyeglasses and telescopes are both special cases of the lens, but their fundamentally different uses seem to me to clearly qualify them for separate listing; fair enough. I'm not sure I would have included the telescope, though. Is the telescope the most useful and important object of its type? Maybe I'm missing something, but it seems to me that most of the uses of the telescope are either scientific or military. The military value of the telescope is not in the same class as the value of the sword or the rifle. The scientific value of the telescope, however, is enormous. So it's on it scientific credentials that the telescope goes into the list, if at all.

But the telescope has a cousin, the microscope. Is the telescope's scientific value comparable to that of the microscope? I would argue that it is not. Certainly the microscope is much more widely used, in almost any branch of science you could name except astronomy. The telescope enabled the discovery that the earth is not the center of the universe, a discovery of vast philosophical importance. Did the microscope lead to fundamental discoveries of equal importance? I would argue that the discovery of microorganisms was at least as important in every way.

Arguing that "X is in the list, so Y should be too" is a slippery slope that leads to a really fat list in which each mistaken inclusion justifies a dozen more. I won't make that argument in this article. But the reverse argument, that "Y isn't in the list so X shouldn't be either", is much safer. If the microscope isn't important enough to make the list, then neither is the telescope.

The level

This is the only tool on the list that I thought was a serious mistake, not quite on the order of the Post-It note, but silly in the same way, if to a much lesser degree. It is another item of the type exemplified by the telescope, an item that is on the list, but whose more useful and important cousin is omitted. Why the level and not the plumb line? The plumb line does everything a level does, and more. The level tells you when things are horizontal; the plumb line tells you when they are horizontal or vertical, depending on what you need. The plumb line is simpler and older. The plumb line finds the point or surface B that is directly below point A; the level does nothing of the kind.

I'm boggled; I don't know what the level is doing there. But the fact that my most serious complaint about any particular item is with item #18 shows how well-done I think the list is overall.


The needle made the list at #13, but thread did not. A lot of sewing things missed out. Most of these, I think, are not serious omissions. The spinning wheel, for example: hand-spinning works adequately, although more slowly. The thimble? Definitely not in the top twenty. The button, with frogs and other clasps included? Maybe, maybe not. But one omission is serious, and must be considered seriously: the loom. I suppose it was eliminated for being too big; there can be no other excuse. But the lathe is #12, and the lathe is not normally small or portable.

There are small, portable lathes. But there are also small, portable looms, hand looms, and so on. I think the loom has a better claim to being a tool in this sense than a lathe does. Cloth is surely one of the ten most important technological inventions of all time, up there with the knife, the gun, and the pot. Cloth does not belong on the Forbes list, because it is not a tool. But omission of the loom surprises me.


Similarly, the omission of the windmill is quite understandable. But what about the quern? Flour is surely a technology of the first importance., Grain can be ground into flour without a windmill, and in many places was or still is. This morning I planned to write that it must have been omitted because it is hardly used any more, but then I thought a little harder and realized that I own not one but two devices that are essentially querns. (One for grinding coffee beans, the other for peppercorns.) I wouldn't want to argue that the quern is on the top twenty, but I think it's worth considering.

Male bias?

In fact, the list seems to omit a lot of important handicraft and home items that have fallen into disfavor. Male bias, perhaps? I briefly considered writing this article with the male-bias angle as the main point, but it's not my style. The authors might learn something from consideration of this question anyway.

The pot made the list, but not the potter's wheel. An important omission, perhaps? I think not, that a good argument could be made that the potter's wheel was only an incremental improvement, not suitable for the top twenty.

I do wonder what happened to rope; here I could only imagine that they decided it wasn't a "tool". (M. Ewalt says that he is at a loss to explain the omission of rope.) And where's the basket? Here I can't imagine what the argument was.


With the mention of baskets, I can't put off any longer my biggest grievance about the list: Where is the bag?

The bag! Where is the bag?

I will say it again: Where is the bag?

Is the bag a small, portable implement? Yes, almost by definition. "Stop for a minute and think about what you've done today--every job you've accomplished, every task you've completed." begins the Forbes article. Did I have my bag with me? I did indeed. I started the day by opening up a bag of grapes to eat for breakfast. Then I made my lunch and put it in a bag, which I put into another, larger bag with my pens and work papers. Then I carried it all to work on my bicycle. Without the bag, I couldn't have carried these things to work. Could I have gotten that stuff to work without a bag? No, I would not have had my hands free to steer the bicycle. What if I had walked, instead of riding? Still probably not; I would have dropped all the stuff.

The bag, guys!. Which of you comes to work in the morning without a bag? I just polled the folks in my office; thirteen of fourteen brought bags to work today. Which of you carries your groceries home from the store without a bag? Paleolithic people carried their food in bags too. Did you use a lathe today? No? A telescope? No? A level? A fish hook? A candle? Did you use a bag today? I bet you did. Where is the bag?

The only container on the Forbes list is the pot. Could the bag be considered to be included under the pot? M. Ewalt says that it was, and it was omitted for that reason. I believe this is a serious error. The bag is fundamentally different from the pot. I can sum up the difference in one sentence: the pot is for storage; the bag is for transportation.

Each one has several advantages not possessed by the other. Unlike the pot, the bag is lightweight and easy to carry; pots are bulky. You can sling the bag over your shoulder. The bag is much more accommodating of funny-shaped objects: It's much easier to put a hacked-up animal or a heterogeneous bunch of random stuff into a bag than into a pot. My bag today contains some pads of paper, a package of crackers, another bag of pens, a toy octopus, and a bag of potato chips. None of this stuff would fit well into a pot. The bag collapses when it's empty; the pot doesn't.

The pot has several big advantages over the bag:

  1. The pot is rigid. It tends to protect its contents more than a bag would, both from thumping and banging, and from rodents, which can gnaw through bags but not through pots.

  2. The pot is impermeable. This means that it is easy to clean, which is an important health and safety issue. Solids, such as grain or beans, are protected from damp when stored in pots, but not in bags. And the pot, being impermeable, can be used to store liquids such as food and lighting oils; making a bag for storing liquids is possible but nontrivial. (Sometimes permeability is an advantage; we store dirty laundry in bags and baskets, never pots.)

  3. The pot is fireproof, and so can be used for cooking. Being both fireproof and impermeable, the pot enables the preparation of soup, which increases the supply of available food and the energy that can be extracted from the food.

The bag probably predates the pot. To make pots, you must locate a suitable source of clay, shape it, and sun-dry or bake it. To make a bag requires nothing more than to grab a large animal skin by the corners. The bag doesn't get as much notice by anthropologists—not because it's less important, but because it's not as durable. We have potsherds that are thirteen thousand years old. All the bags that old have long since turned to dust.

I have no objection to Forbes' inclusion of the pot on their list, none at all. In fact, I think that it should be put higher than #16. But the bag needs to be listed too.

Other possible omissions

After the hammer, the bag, and rope, I have no more items that I think are so inarguable that they are sure substitutes for items in Forbes' list. There are items I think are probably better choices, but I think it is arguable, and, as I explained at the beginning of the article, I don't want to take cheap shots. Any list of the 20 most important tools will leave out a lot of important tools; switching around which tools are omitted is no guarantee of an objectively better list. For discussion purposes only, I'll mention tongs (including pliers), baskets, and shovels. Of the items on Forbes' near-miss list that I would want to consider are the bow, the broom and the spoon.

Revised list

Here, then, is my revised list. It's still not the list I would have made up from scratch, but I wanted to try to retain as much of the Forbes list as I could, because I think the items at the bottom are judgement calls, and there is plenty of room for reasonable disagreement about any of them.

Linguists found a while ago that if you ask subjects to judge whether certain utterances are grammatically correct or not, they have some difficulty doing it, and their answers do not show a lot of agreement with other subjects'. But if you allow them an "I'm not sure" category, they have a lot less difficulty, and you do see a lot of agreement about which utterances people are unsure about. I think a similar method may be warranted here. Instead of the tools that are in or out of the list, I'm going to make two lists: tools that I'm sure are in the list, and tools that I'm not sure are out of the list.

The Big Eight, tools that I think you'd have to be crazy to omit, are:

  1. Knife (includes sword, axe, scythe, chisel, spear, shears, scissors)
  2. Hammer (includes club, mace, sledgehammer, mallet)
  3. Bag (includes wineskin, water skin, leather bottle, purse)
  4. Pot (includes plate, bowl, pitcher, rigid bottle, mortar)
  5. Rope (includes string and thread)
  6. Harness (includes collar and yoke)
  7. Pen (includes pencil, writing brush, etc.)
  8. Gun (includes rifle and musket, but not cannon)
The lesser twelve, the tools that I'm not sure are off the list, are:

  1. Compass
  2. Plumb line (includes level)
  3. Sewing needle
  4. Candle (includes lamp, lantern, torch)
  5. Ladder
  6. Eyeglasses (includes contact lenses)
  7. Saw
  8. Balance
  9. Fishhook
  10. Lathe
  11. Abacus (includes counting board)
  12. Microscope
My lists merge the sword, scythe, and chisel under the knife. This frees up space for the hammer, the bag, and rope, which I think were Forbes' most serious omissions. The only other omission I felt that I had to correct was the ladder; I removed the watch to make room, although I had misgivings about that.

The other adjustments are minor: The pot got a big promotion, from #16 to #4. The pencil is represented by the pen, instead of the other way around. The rifle is teamed with the musket as "the gun". The telescope is replaced with the microscope. The level is replaced with the plumb line. The scale is replaced by the balance, which is more a terminological difference than anything else.

The omission of mine that worries me the most is the basket. I left it out because although it didn't seem very much like either the pot or the bag, it did seem too much like both of them. I worry about omitting the pin, but I'm not sure it qualifies as a "tool".

If I were to get another 13 slots, I might include:

  1. Basket
  2. Broom
  3. Horn
  4. Pry bar
  5. Quern
  6. Radio (Walkie-talkies)
  7. Scraper
  8. Shovel
  9. Spoon
  10. Tape
  11. Tongs
  12. Touchstone
  13. Welding torch
[ Addendum 20120628: National Geographic reports the discovery of the oldest known "purse", estimated to be between 4200 and 4500 years old. The purse itself has disintegrated, leaving only its exterior decorations: a hundred dog teeth. ]

[ Addendum 20190610: Miles Gould points out that the bag may in fact have been essential to the evolution of human culture. This blog post by Scott Alexander, reviewing The Secret Of Our Success (Joseph Henrich, Princeton University Press, 2015) says, in part:

Humans are persistence hunters: they cannot run as fast as gazelles, but they can keep running for longer than gazelles (or almost anything else). Why did we evolve into that niche? The secret is our ability to carry water. Every hunter-gatherer culture has invented its own water-carrying techniques, usually some kind of waterskin. This allowed humans to switch to perspiration-based cooling systems, which allowed them to run as long as they want.

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