was created, and the nomothetai were the officials responsible for preserving the integrity of the publicly inscribed laws. Procedures to maintain the authority of the laws were introduced. 
Along with the standardized alphabet, the reinscribed laws, and the new offices, the Athenians reinforced a conceptual and procedural distinction between a written law (nomos) and a decree of the Assembly ( psephisma). Nomos meant custom and law, but after 402 b.c. the term came to mean a fundamental law that was inscribed in public view. A nomos was understood to be a stable standard that was, ideally at least, not subject to the shifting arguments of orators. In contrast, a psephisma was a decree passed by a vote of the Assembly, directed against a particular situation. 
Evidence strongly suggests that Athenians were conceptually precise about the distinction between a decree of the assembly (a psephisma) and a written law (a nomos). Mogens Herman Hansen supports this contention first with fourth-century epigraphic evidence: some five hundred inscriptions refer to psephismata, and some six refer to nomoi. Despite the disparity in the amount of evidence, Hansen observes the strict institutional distribution between the two political acts: "There is no example of a nomos passed by the demos [the Assembly] or of a psephisma passed by the nomothetai [the officials charged with maintaining the written laws]." Literary sources are also consistent; of some two hundred psephismata passed by the Assembly that are cited in the work of orators and historians, there are only five cases in which an enactment by the Assembly is referred to as a nomos. Nor is any measure referred to by both terms. Given the looseness with facts for which the orators are famous, this distribution of terminology is evidence for a strong conceptual distinction between the two terms, as well as for a strong distinction between the institutions responsible for each type of enactment. 
One essential attribute of a nomos was to be written. The Athenians understood that to write a law is to preserve it in a way that is not subject to the vagaries of memory. Because a nomos was written and carried the force of tradition, it was more stable than a decree, and less susceptible to the winds of whim that blew through the Assembly and its votes. The Assembly could break a written law if it wished -there was no institutional authority above it-but the written laws were available for all to see.Aperson making proposals before the Assembly who tried to undermine the written laws would face opposition from those who valued the laws. Although the legal orators of the fourth century were notorious for inventing laws -not everything was written-there is good reason to think that the original laws of Solon, written in the first two decades of the sixth century and lost after the sack of Athens by the Persians in 480 b.c., had regained their moral and legal force. The mere mention of Solon's name in fourth-century Attic law speeches was a powerful claim to legitimacy. 
Hansen, Ecclesia I, 163-67, shows that the five exceptions were all in the fifth century. He finds no exceptions after 400 b.c. Hansen also shows that, with one exception, the "demos" is never credited with passing a nomos in the fourth century. The sole exception, Demosthenes 59, Against Neara 88f., may hinge on the sense in which "demos" is used, and is not sufficient reason to consider the pattern broken. This was also understood by Aristotle; see Nicomachean Ethics 5.10, 1137b11-32 (a nomos is a general, standing rule; a psephisma applies to the facts of the moment). In my view, the "open texture" of Athenian law is the use of generalizations applied to particular cases, and the issue turns on this philosophical point.
A nomos was also more general than a psephisma: a written law was a generalization of wider scope than an Assembly decree. Like a law-court, a meeting of the Assembly generally dealt with particula