The Imperial System is Inferior to the Metric System

First, we have the unit for length. The unit for length is defined as a ten millionth of the distance from the equator to either of the poles. This unit of length is called the meter, and if you traveled from the equator to either of the poles, you would have traveled ten million meters. And since the distance from the equator to either of the poles is a fourth of the earth's circumference, that means that the earth's circumference is forty million meters.

From there, we can use this unit of length to define a unit for volume. Simply make a cubic area where each side-length is a tenth of a meter, and you have the unit that is known as the liter.

From there, we can use this unit of volume to define a unit for weight (not the same as mass). Take one liter of volume, and fill it with water. The weight of one liter of water is the unit that is known as a kilogram.

Now that we have our units, we might consider creating prefixes for describing quantities. Rather than referring to "one tenth of a meter," or "seven billionths of a meter," you could simply put a prefix in front of the word, and it will describe how much of the original unit that quantity represents. Here are the prefixes, and the quantities they represent:

So, a tenth of a meter is really just a decimeter, which defines a liter as one cubic decimeter. We can therefore realize that a kilogram is actually one thousand grams. So, one gram would be one cubic centimeter of water. Kilometers are the most standard way to measure large distances within the metric system. As you can see, this system is logical, and it's easy, because calculations are now just a matter of moving the decimal point. It's also based on things that make perfect sense, so it all comes together.

The advantage of the Imperial System is that you technically don't need a ruler, you can just use your body. The foot is a unit of length equal to 0.3048 meters, and is approximately the length of the average man's foot. Make no mistake, it is not the measurement that is not precise, it's the size of the average man's foot that's not precise. But this does mean that if you're just getting approximate values, you can use your feet to measure to a decently close degree of precision how many feet long something is. Of course, that only works if you are an average sized adult male, which means that people who don't have an average build, or women, or kids, might have a harder time getting a precise answer.

The inch is one twelfth of a foot, and is equal to two things: 1. the length of the average man's thumb. 2. three grains of barley laid end to end. So, alternatively, instead of using your feet to measure things, you could also use your thumbs to measure things.

Despite all of these things, people will still use precise rulers to measure things in Imperial measurements, because again, it's only a certain type of person that will be able to easily use their body to measure things. It's only good for approximate values, not precise ones. If you want precise values, you're going to have to use rulers, which beat the entire purpose of the Imperial System. Not to mention, converting between units is a nightmare.

Up until now, I've been talking about units within the Imperial System that can be approximately measured using your own body. But the mile is not. The mile is the way the Imperial System measures large distances. It is the Imperial System's equivalent to kilometers. And a mile is defined as 5,280 feet. WHAT??? What kind of random and specific number is that? Sure, the ancient people have their reasons, but we are not the ancient people, and we shouldn't have to deal with these kinds of numbers.

Their unit for weight is defined as the weight of seven thousand grains, and that is called the pound. Again, where are they getting these numbers? And why grains? What grains are we talking about? Grains are not one entity, and they can be variable in size.

The ounce is any of several different units of mass, weight, or volume. So, there are multiple units called the ounce!

Their unit for volume is the pint, but eight pints can make a gallon. Why can't it just be ten?

As you can see, the Imperial System gets rather messy and random. A foot is 12 inches, and a mile is 5,280 feet, and a mile is also 63,360 inches. You know how many meters there are in a kilometer? It's in the name, it's 1,000. And you know how many centimeters there are in a meter? Again, it's in the name, it's 100. It's all tens, which makes calculations really easy to do, and it's just generally very easy to comprehend. But the Imperial System has so many random, specific, and out of line numbers that require calculators, or intense amounts of math in general. It's confusing, and it's illogical. We live in a day and age where we don't have to use our bodies to measure things, because we have invented very precise, and very accurate systems of measurement, so that things can be precise. The Imperial System is simply inferior because of this, and it no longer needs to exist. The metric system is clearly much easier to calculate, and it's more logical in nature. It's a great system, and things work together in unison.

The metric system is kilometers ahead of the Imperial System. It's simple, it's logical, and it's easy. The Imperial System is not. The Imperial System is inferior to the metric system in many ways, as I have shown you above.

Thank you, Pro. This will be a devil's advocate debate for me.

As Pro has neglected to precisely define the key terms in this debate, I will do so here.

Imperial system:

1. The system of units of measurement first developed in England and defined under British law

2. The substantially similar descendent system used in the United States of America

I include this second definition because it is clear my opponent makes reference chiefly to the American customary system of measurements. Technically speaking, this system is called just that, the American customary system, but it is often referred to as the imperial system due to being directly descended from it. Really, there's not many differences between the two, mostly just some obscure units. Thus, except where I make a distinction between the two systems, the terms "imperial system" and "imperial units" may be considered synonymous with "US customary system" and "US customary units". Since that is how my opponent has been using these terms, I trust they will find this acceptable.

Metric system: A decimal-based system of measurements first invented in 1795

International System of Units (SI): A system of seven units that forms the modern basis of the metric system

As Pro, my opponent has the primary burden of proof to show that the imperial system is inferior to the metric one. They have neglected to clearly state in the description of this debate an exact standard by which the two should be judged, ultimately leaving it up to opinion. As Con, I have no need to prove that the imperial system is superior. I only have to try and undermine Pro's argument and show how they have not met their burden of proof.

In his opening argument, my opponent makes two main arguments: the first is that the metric system is based on unchanging aspects of our world, while the imperial system isn't. The second is that the metric system is optimized for decimal notation, making it simpler than the imperial system. I will be responding to these one by one.

My opponent seems to be lacking in some core knowledge on this topic, and that is demonstrated right at the very beginning of their opening argument.

This is not correct. My opponent is using a definition of the meter which has long been outdated. In the modern day, the metric system is based on the International System of Units, abbreviated SI, from the French Système international d'unités. Under the SI system, the meter is based on the speed of light in a vacuum, which is defined to be 299,792,458 meters per second. This means that the meter is also implicitly based on the Cesium standard, which defines the second.

My opponent also incorrectly defines the kilogram, which he says is the weight of a liter of water. In fact, today the kilogram is based on the Planck constant, which is defined to be 6.62607015×10^(−34) J⋅s. A joule is defined as a kg⋅m^2/s^2, so if you have a definition for the meter and the second, you have a definition for the kilogram, which is a unit of mass, not weight.

So, why am I bringing this up? This seems to hurt my case, right? Well, no. Because my opponent is also ill-informed about how the imperial system is currently defined, stating: 

While it is true that those units do ultimately trace their origins to those things, that's not how they have been officially defined for centuries. As far back as 1824 in the UK, the yard was based on a physical standard.(1) Until 2019, the kilogram was also based on a physical standard.(2) For a time prior to 1960, even the meter was defined based on a standard.

In the modern day, however, the imperial units are defined based on metric units, and the metric units are based on the SI units, a set of seven distinct units all derived from universal constants and natural laws. Thus, the imperial units are also implicitly based on these natural constants. This has been true since at least 1959, when an international agreement defined the English yard and pound in terms of the metric meter and kilogram, respectively. (3)(pdf). Beyond that, converting from Celsius to Fahrenheit is a simple matter - multiply by 1.8 and add 32. Mass, length, and temperature are the areas where the imperial and metric systems differ. Everything else is derived.

I should also note a pretty blatant flaw in my opponent's argument. He says:

The logical problem with this argument is obvious. If you didn't already know roughly how long a meter is, would you be able to accurately judge the length of something based on units of measurement equal to a ten millionth of the distance from Earth's equator to either of its poles? No, of course not, that's ridiculous. You need some sort of measuring instrument. Under the imperial system, you also need an instrument to be precise, but you can also use body parts to estimate. My opponent has already conceded that the imperial system has a distinct advantage! But I'm running out of characters, so I need to move on.

My opponent argues that the metric system is based on the decimal number system, which makes conversion simpler. This is true. However, while this simplicity is the greatest advantage of the metric system, it is also its biggest downside. Let me explain.

The metric system takes the base-10 number system (the decimal system) for granted. This is understandable, given its history and how essentially all European languages are base-10 when it comes to numbers. (I'm unaware of any exceptions, but ironically, French comes close as it has the remnants of a base-20 system, which is why 90 in French is 'four-twenties-ten.') However, its insistence on using only powers of ten to define any sort of  unit other than a base unit means that the metric system effectively only has one unit for each field of measurement. There is no difference between saying 'a kilometer' and 'a thousand meters'. 'A milliliter' and 'a thousandth of a liter' are exactly synonymous. If you speak a language with a decimal number system, the metric system effectively gives you only one unit for each thing it measures.

This is certainly simple, but being simpler isn't always better. Astronomers measure truly mind-boggling, incomprehensibly large distances. Given that astronomy is a field of science, you might expect to see lots of mentions of megameters, gigameters, terameters, and so forth, but astronomers tend to use other units such as the AU, parsec, solar radius, and light year. None of these are defined as some power of ten times a meter. Further, even when astronomers do use meters to measure such long distances, they often tend to use scientific notation rather than the prefixed units.

This demonstrates two things at once: first, that defining everything in terms of one unit is not always desirable - otherwise, modern science wouldn't be using those alternate astronomic units of length. Second, all those metric prefixes my opponent listed in full don't actually add any value that scientific notation doesn't already give us.

The imperial system recognizes the value that using different units can provide, which my opponent fails to do, stating:

The English mile was based on the Roman mile, which was defined to be 1,000 paces (a power of ten!). Later, it was defined in terms of the English yard so that it could be precisely defined. There is some good sense to this, as it is much easier to accurately judge a long distance in terms of paces than human feet or thumbs. Sure, converting from feet to miles or vice-versa might not be easy to do in your head, but how often is it actually necessary? The distances that tend to be measured in miles are rarely well-represented in feet. If I say the distance from New York to Chicago is roughly 711 miles, are you going to complain that you can't figure out in five seconds that that's 3,754,080 feet? No, because why would you measure that distance in feet? The metric system, however, does require you to state that the distance is about 1.144 million meters. It just allows you to say 1,144 km for short.

Further, a foot is 12 inches for a good reason. 12 is an 'antiprime' number, a natural number with more divisors than any smaller natural number. So, a third of a foot is 0.3333.... feet, but you can convert to inches and just write 4 inches. The decimal terminates when you convert the units. This is impossible under the metric system.

Further, any advantage given by metric being based on base-10 also evaporates if one is using a different number system entirely. Not everyone uses such a system. The Ndom language spoken on Papua New Guinea has a base-6 (aka senary) number system.(4) Under base-6, a kilometer is 4,344 meters. Hardly convenient or easy!

I have more to say but I'm out of space. My opponent now has the floor.

Thank you, Con.

I can't think of any refutations to your definitions, so I will use them also.

It is true that I do have the burden of proof in trying to prove that the Imperial System is inferior to the metric system. However, if you're arguing against me, then you have to show that the Imperial System is not inferior to the metric system. Therefore, you have to show that the Imperial System is better than the metric system. Or, I suppose, you could just try and discredit the logical integrity of my arguments.

I must clarify that when I was defining the magnitude of each unit within the systems of measurement and what they represented, I was explaining what their original definition was. We simply changed the definitions, but kept the units exactly the same (except for a bit recently when they changed the kilogram, and apparently some others). As far as I'm aware, they never did that with the Imperial System though, and so the magnitude of the units have remained the same. It's just their modern definitions that are different.

And, yeah, if you were not able to accurately estimate how long a meter is, you would not be able to simply take the distance from the equator to either of the poles, divide that by ten million, and use that as a standard. But the point I was trying to make was that if you've ever gone to measure something in your house using Imperial units, how often do you use your feet and thumbs? And how often do you use your ruler or tape measure? Because most people have a tape measure/ruler in their house, and people in America will use its Imperial units. When construction workers are working on the blueprints for a house, if they're in America, they will make it in Imperial units. They definitely did not use their feet and thumbs to approximately measure, because that's not at all how the world works anymore, or basically at any time (the ancient people were smarter than we all thought). And so, they simply use tape measures, rulers, and other tools that are built with exact measurements to make sure that their measurements are exact, which they could have done just as easily using a metric tape measure, had America not been calibrated on the Imperial System, which is irrelevant to the logical integrity of said system. Sure, you can use your body to measure in the Imperial System, but that's about it. That's the only advantage the Imperial System has, which means that if you were measuring using an exact tape measure and not your body, you have no reason to use the Imperial units outside of being calibrated on the Imperial system, which again is irrelevant to its logical integrity. Because if you're using a tape measure, you could have just as easily used it in metric units, which would have made further calculations much easier to perform.

Currently, almost the entire human race uses the base-10 system, so much so that the average person (including myself until I read your argument), has no idea that anyone else uses anything differently. It's so ingrained in our heads now that it never occurs to us that using any other base system would work just as well for calculations, but we chose base-10 because we have ten fingers. The point is, even though there might be some random obscure places and numbering systems that are not the same as ours, it remains to be such an immense majority of the world population that uses the base-10 numbering system that it's almost international. It's certainly something that could never ever occur to someone that they would be just fine using a different system.

But also, let's say that I go to Papua New Guinea and start using the metric system. If I introduced them to the metric system, what could be done, (and if understood, it might not be that hard to convert between), is define the prefix "deca" as five instead of ten, define "hecto" as 25 (which is their hundred), define "kilo" as 125 (which is their thousand), and so on. It wouldn't be hard at all to simply redefine these prefixes for their system. So, this system is variable to any base system you want, and is not solely fixed. All you need are the base units, and what are variable are the meaning of the prefixes, which are going to be calibrated onto whatever system you use. Whichever one you use, it can work! It doesn't matter if you use base-6, or base-10, or base-12, or even base-60, it can work! So no, the metric system does not fall apart when the system changes, though yes, it could cause complications for converting between base-6 metric and base-10 metric, but that's not much of a problem anyway, because base-10 is almost completely international.

We live in a modern world now where approximate values of regular human activities aren't very good definers of units of measurement, which is why 1,000 paces isn't that great of a basis for a unit of measurement in today's modern world. We don't even use paces anymore, we're stuck with feet I guess.

And, if I wanted to know what a 749th of a kilometer is, I know how many meters that is: 749m. Very simple.

And yeah, astronomers are going to use astronomical units and parsecs and solar radii, but ain't nobody is measuring in units equal to the distance from the earth to the sun here on earth. Astronomers have their own units, but that's just for astronomy, not for pretty much everything else.

And, wouldn't you rather say a kilometer instead of saying one thousand meters, or even worse, saying 10^3 meters? Why must I have to say "2.2 x 10^23 meters" when I could just say "2.2 yoctometers." That's much easier to say, and rolls off the tongue better (not completely, but just better).

If I wanted to convert from feet to inches, I would need to multiply feet by 12. If I wanted to convert feet to miles, I would need to divide by 5,280. If wanted to convert gallons to pints, I would need to multiply by 8.

If I wanted to convert from meters to centimeters, I would need to divide by 100. If I wanted to convert meters to kilometers, I would need to divide by 1,000. If I wanted to convert liters to centiliters, I would need to divide by 100. Just look at all those flat, clean, base-aligned numbers.

And as I stated earlier, no, the metric system is not entirely calibrated on base-10. All that's stopping us from converting to base-6 is the definition of the prefixes, which can easily be calibrated on a different numbering system, and you'll be good. In which case, if I wanted to convert from meters to centimeters, I would need to divide by 25 (which, while it seems random in base-10, it is just as logical as my previous demonstration of the metric system when used in base-6, which is the point I'm making here). If I wanted to convert meters to kilometers, I would need to divide by 125. If I wanted to convert liters to centiliters, I would need to divide by 25. But again, all of these numbers may seem random in base-10, but they made perfect sense and are just as easy as our metric system when used in base-6. And so, if you were to simply change the definitions of the prefixes, you'd be good! Also, I may have gotten my calculations wrong, my head was spinning trying to figure out how to translate base-10 numbers into base-6, and then show how much their number is in base-10 numbers, but you get the idea.

It still stands that the metric system is way more logical and way more easy than the Imperial system when running calculations. And, it can be converted into different counting systems simply by changing the definitions of the prefixes to align with their system. And so, they can be converted, and rather easily so! When I convert from one metric unit to another metric unit, I don't have to use a calculator, I just move the decimal point. Easy!