People have been extolling the advantages of the metric system for decades without convincing anyone that a meter is better than a yard merely because it is divisible by ten. Now that all the attempts to convince the American public that it is more handy or more "rational" than our old-fashioned units of measure have failed, I am left questioning why it was ever attempted in the first place.
The reasoning behind the adoption of the metric system was fairly straightforward, if not well enough argued: why have a system of measurement that is based on antiquated and outmoded standards (for example, a mile is made up of 5,280 feet) when there is another system in which every unit is more easily calculable by the number ten? Scientists have been using the metric system exclusively for this reason, so why shouldn't everyone else use it?
The problem with switching to a different system is more than just familiarity with the old one. Regardless of the fact that it would take years for everyone to accustom themselves to a new system, there is no convincing reason to switch. Having lived for several years in Asia, in Japan, Korea, and the Philippines, countries which use the metric system for everything, I am no closer today to being comfortable with it than when I first arrived. When I or someone close to me is feeling ill and I want to take their temperature, I still have trouble accepting 37 degrees as a "normal" temperature, equivalent to 98.6 degrees Fahrenheit. Nor is the prevailing heat in the Philippines any more bearable because it is measured as 36 degrees rather than 95. Nor do any of my vital statistics make sense to me, like my height (178 centimeters) or my weight (85 kilos).
When I was in the Army, I would participate in what were called road marches, which were nothing but long hikes in troop boots with overloaded ruck sacks that destroyed my feet. In Korea there was the infamous "Manchu Mile" road march, which was actually 25 kilometers, or 15 1/2 miles. It was one of the few occasions when the metric system was an agreeable alternative.
When I started driving in Okinawa, on the left side of the road and the steering wheel on the right side of the car, I noticed that the speed limit of 40 kmph seemed a little slow. When I figured out that it was 25 mph, I realized that speeding was the only way I was ever going to get anywhere.
Another problem to consider is the eventual loss of our understanding of the old system used in our literature. Will we have to convert Shylock's pound of flesh into .45 kilo? And how prosaic it would sound if Robert Frost had had "kilometers to go" before he slept!