Essential elements of Roman "labour law"

(a) Locare conducere

"Simile est regnum coelorum homini patrifamilias, qui exiit primo mane conducere operarios in vincam suam, conventione autem facta cum operariis ex denario diurno, misit eos in vineam suam.

We all know the parable of the labourers in the vineyard. Quite apart from its theological significance, it gives us a vivid picture of how the labour market worked—in Rome as much as in Galilee. It was the place where people offered themselves into service. They were prepared to work for somebody else, and this involved, first of all, that they made themselves available for a change of place (locare,^{[1929] [1930] as derived from locus). The employer/master, in turn, took them along or instructed them where to go, and his activity was described as conducere. We are dealing here with the second of the cardinal types of locatio conductio: the contract of service, or locatio conductio operarum, as it was termed by the lawyers of the ius commune. "Operae" are services,[1931] services as such and without reference to a specific result to be achieved. Where such result was contemplated, one spoke of "opus".}

(b) Essentialia negotii; periculum conductoris

By and large, locatio conductio operarum followed rules similar to locatio conductio rei. It was a consensual contract, and the parties had to agree on two essentialia negotii: the services to be rendered (operae) and the remuneration to be paid (merces).^[1932] The remuneration had to consist in money and could not merely be a token amount.^[1933] The employer could avail himself of the actio conduct! to enforce due per­formance of the services promised; if he did not pay the merces, he was liable to his employee under the actio locati.

(c) Imperitia culpae adnumeratur

The employee obviously had to do what was required of him diligently. It is probable (though not certain),^[1940] that the employer was liable (only) for culpa and not for custodia. Such culpa could, however, appear in the interesting guise of imperitia: imperitia culpae adnumeratur.^{[1941] [1942] The muleteer whose services were hired, provides an example:}

"Mulionum quoque, si per imperitiam impetum mularum retinere non potuerit, si eae alienum hominem obtriverint, vulgo dicitur culpae nomine teneri. idem dicitur et si propter infirmitatem sustinere mularum impetum non potuerit: nee videtur iniquum, si infirmitas culpae adnumeretur...."^t4

Mules can be vicious and obstinate, and in order to be able to handle them, a considerable amount of skill and strength is required. If the muleteer lacks such skill or strength and consequently is unable to control the mules, he is liable, even though, considering his limited capabilities, it might be difficult to blame him either for his actions or for his failure to act at the time when the incident happened. His fault, however, consisted in offering to perform a service without being competent therefor; for the conductor may reasonably expect the locator to possess both peritia and firmitas for the specific service which the latter undertakes to render.^[1943]

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