The weight of Wittgenstein's standard metre

Paragraph 50 of Wittgenstein's Philosophical Investigations famously says that there is one thing of which one can neither state that it is 1 m long nor that it isn't: the standard metre in Paris. Consensus appears to be that (1) exegetically speaking, Wittgenstein affirms this claim, and (2) systematically, whether or not one agrees with it, the practice of using a material artefact as a measurement standard has important philosophical consequences. In this paper, in contrast, we show that (1(')) Wittgenstein does not affirm the standard metre claim and (2(')) historical facts about material length standards do not warrant deeper philosophical conclusions. References to material measurement standards in the literature gravely distort the actual metrological practices of developing and using such standards.