Stare decisis is the common law doctrine that judges are bound to uphold previous decisions. It is more commonly known as the doctrine of precedent. There is a tendency to think of adherence to precedent as somehow closely related to custom; by binding themselves to precedents, judges are thought to preserve customary ways of doing things. By contrast, legislation overturns precedents and customary law.
However, a precedent is a precedent because at some point in past time it was first established as such. It may even have become established by overriding a previously established precedent or custom.
More interestingly, though, are situations where precedent points in one direction and custom points in another. The following story from the Roman historian Livy (Bk. 27, ch. 8) illustrates what I’m getting at.
The Priesthood of Gaius Flaccus
In 209 BC Gaius Valerius Flaccus, a young and dissolute Roman nobleman was assigned — very much against his will and inclination — to the position of flamen Dialis, a priesthood associated with the god Jupiter. Perhaps it was hoped that the various taboos and constraints associated with this priesthood would have a reformative effect on the young prodigal’s character.
It seems to have worked, for by all accounts Flaccus transformed himself into a serious, diligent, and virtuous citizen. However, a complication arose when Flaccus attempted to claim a seat in the Senate by right of his priestly office. He was opposed by the praetor Publius Licinius, on the ground that no flamen Dialis had claimed a Senate seat in living memory. According to Livy, “the praetor maintained that a right was based not upon outmoded instances from the annals, but in each case upon very recent practice [consuetudinis = ‘custom’].” In short, the praetor appealed to current custom or practice, rather than to ancient precedents.
(Although Livy doesn’t say as much, there may have been a problem with Flaccus’ age: the term senatus is related to senex, or “old man”, implying that the Senate was supposed to be a council of elders, while Flaccus was a mere youth.)
On the other hand, the tribunes defended Flaccus by claiming that the fact that recent priests had neglected to exercise their right should have no bearing on whether or not Flaccus could exercise it. As they put it, “obsolescence due to the indolence of flamens was justly accounted their own loss, not a loss to the priestly office.” In other words, precedent — however old or outdated — trumps custom. The precedent speaks for a Senate seat being attached to the office of flamen Dialis, regardless of the custom or practice of particular holders of the office.
The position of the tribunes was probably the correct one: rights should follow precedent, not custom. If I have, for example, a right to free expression that is constitutionally guaranteed to me by virtue of my status as a citizen, I do not lose that right because my fellow citizens have chosen not to exercise their similar right. Only a change in legislation could have this effect (and if one believes in “natural rights”, then not even then).
So what was the outcome for Flaccus? According to Livy, neither custom nor precedent decided the matter. Rather, Flaccus won his seat, “for it was the opinion of everyone that the flamen had carried his point rather by the uprightness of his life than by virtue of priestly privilege.” Thus, it remains an open question how the case would have been decided if Flaccus had not undergone a reformation of character.
Andrew Lintott. The Constitution of the Roman Republic. Oxford: Oxford University Press, 1999.
Livy. History of Rome (Vol. VII). Frank Gardner Moore (trans.). Cambridge, MA: Harvard University Press, 2004.
Richard E. Mitchell. “The Definition of patres and plebs: An End to the Struggle of the Orders,” in Kurt A. Raaflaub (ed.), Social Struggles in Archaic Rome. Oxford: Blackwell, 2005.
Fritz Schulz. Principles of Roman Law. Oxford: Clarendon Press, 1956.