Andrew M. Riggsby
As the organizers point out, standardization of weights and measures is near-universal operation of states, but it would be surprising if all states carried this out with equal zeal and efficiency. This paper explores the limits of standardization in the Roman Empire, particularly (though not exclusively) in terms of the incentive structure created by the legal system. Appeal to universal standards was rarely required by the state, whether in its own interactions with private persons or between two such parties. Nor were persons who voluntarily relied on such standards rewarded indirectly by the commercial law. These limits are then located in a broader metrological culture, which was not only non-standardized, but anti-standardization, and this context shaped andlimited the state’s interventions.
(1) Prior to the question of use, even the broad spatio-temporal availability of standards is subject to doubt because the very diversity of available options undercutthe value of any individual one. (The evidence on this point is weak and better studiedin previous scholarship than most of what follows. I simply note briefly that a minimalist reading is at least plausible.)
(2) Mechanisms for direct enforcement of standards in transactions between twoprivate parties by state officials were weak, localized, and quite literally something of a joke. Market standards were (apparently) only enforced by local authority (and perhapsto local standards) and without penalty, and even then enforcement actions seem to be regarded ipso facto as overzealousness on the part of the magistrates concerned (Juv. 10.100-102, Persius 1.129-130, Ulp. D. 19.2.13.8; cf. Frayn, Markets and Fairs 110f.).
(3) Interactions between state and individual, such as payment of taxes anddistribution of water, were often arranged so as not to require measurement to a universal standard. Instead, they operated by proportion, and indeed often byproportions valid only within a fairly local context (e.g. OGIS 2.674, IGRP 3.1056 [tax]; CIL 6.1261, 8.4440, 14.3676 [water]). While there are numerous exceptions, when the state could (and in fact did) dictate the terms of interaction, it did not systematicallyimpose standardized weights and measures.
(4) The indirect effects of how measure was treated in commercial law similarlydid little to privilege standardization. The law allowed parties to choose their own measures, and particularly recognized regional diversity (Pap. D. 18.1.71). More indirectly, but perhaps more importantly, Roman law appears not to have recognizedgeneric sale by quantity (Gaius D. 18.1.35.5 with Zimmermann, Law of Obligations 236-9).That is, no merchandise was understood to have been sufficiently well identified to be an object of sale until it had actually been measured. (Such controversy as exists on thispoint in the legal literature seems to stem not from real evidence, but from begging the present question of standardization.) Individual transactors were not rewarded for conforming to state standards.
The last two points relate to a broader feature of Roman metrological culture. That culture operates to a significant extent by approximation and proportionalitybecause even simple measurement had not become what Latour and Woolgar, Laboratory Life have called an “inscription device.” That is, there was no community of agreement that the written output of some mechanical/procedural operation should be allowed to stand in for a real property of a physical object (as in a modern laboratory, a spectrogram stands in for real properties of some chemical). Treating various weightsand measures as inscription devices is a technological development that cannot simplybe assumed just because it would suit various purposes of the state.