How long is the meter-stick?

Kelly Dean Jolley's paper "Mensurable Confusion?" seems important. At least, it does to me now that I've read it all. It is presented as a response to a paper by Heather Gert that I didn't know, and as a defense of a kind of orthodoxy in Wittgenstein interpretation, so it didn't strike me as essential reading right away. There's also the fact that the first word of the title looks like a typo for 'measurable'--turns out 'mensurable' is a real word and means exactly the same thing in this context as 'measurable,' which is also a real word. But if you get past all this, the paper has some important things to say.

For instance, Jolley says that some people ignore Wittgenstein's methodological remarks and that others make the mistake of treating these remarks as somehow distinct from his philosophical remarks. He suggests that Gert is guilty of the latter mistake, and I think I have been too if it is a mistake.

So why not make this distinction? Jolley notes that in the Tractatus and the Investigations the methodological remarks come amid other remarks, not at the beginning, because they should be understood as part of the same project as the other remarks, the project of dealing with philosophical problems as Wittgenstein understands them.

Following Cavell (generally a good idea), Jolley takes PI 128 (“If one tried to advance theses in philosophy, it would never be possible to debate them, because everyone would agree to them”) not to be saying that such theses would be commonsensical and therefore too obvious to debate. He takes the agreement here to be the kind referred to in PI 241: not agreement in opinions but in form of life.

I wonder what exactly this means. I certainly don't take Wittgenstein to be a common sense philosopher in the way that Moore is. And to understand Wittgenstein's methodological remarks you need to understand what he means by 'philosophy' and 'philosophical problems'. But to identify remarks such as 128 as methodological one has to make some distinction between methodological and other remarks. And Wittgenstein does (or did) elsewhere talk about his remarks as "boring truisms" and said (I think, in the Lectures on Religious Belief) that if anyone disagreed with something he said that he would take it back. So at some time (perhaps before he finished the PI) he seems to have thought something like PI 128 taken in the supposedly wrong way.

If philosophy consists in assembling reminders for a particular purpose, and these reminders consist of grammatical remarks such as "every rod has a length," then it seems to me that there is a sense in which Wittgensteinian 'theses' would be commonsensical. Perhaps PI 128 can also be taken in Cavell's way, but it doesn't look as though that can be the only correct interpretation. I will have to think about this some more though.

By the way, according to Yahoo! Answers:

Originally the meter was 1/10,000,000 of the distance from the equator to the north pole, along the meridion passing through Paris. In 1960 the meter was defined as 1,650,763.73 wavelengths of the orange-red emission line in the electromagnetic spectrum of the krypton-86 atom in a vacuum. In 1983 the meter became how far light traveled in a vacuum in 1/299 792 458 of a second, officially. But this is hard to set up, so in practice, the meter is now 1,579,800.298728 wavelengths of helium-neon laser light in a vacuum, easily measured in your average home garage.

The meter was originally defined by French Scientists when the metric system was created (during the French Revolution, late eighteenth century). The meter was defined as one ten-millionth of the distance from the equator to the north pole on the meridian passing through Paris. They actually attempted to measure this distance, using a mix of geometric calculation and direct measurement, and the result was surprising accurate, within a millimeter. They made a silver bar of that length they calculated, and this was the standard meter, stored in Paris. Over the years international standards committees re-evaluted the meter. Another standard bar was made in 1889, this time made of an alloy of platinum and iridium. But any metal bar was not stable; it shrank and expanded with temperature and pressure, and it was losing metal atoms and gaining impurity atoms. This did not matter until modern technology demanded a more stable standard. So in 1960 an international scientific conference first chose laser light as the basis for the official meter length, set to match the original meter. Thus the meter in the new SI system was first defined using wavelengths of light, and today is defined as the distance light travels in a few billionths of a second, as stated above.

If this is right then the standard meter might or might not be a meter long, and in fact is not exactly one meter long any more. Not to mention the fact that there have been two different standard meters. Wittgenstein's point remains intact though. The point is that "This is a meter long" means different things when said of a sample that defines what "a meter long" means and when said of anything else. In the first case you are specifying a rule, in the second you are making a claim about the world, applying that rule. I hope I'm right about at least this much.