Jon Elster in the context of "Political theorist"

A constituent assembly (also known as a constitutional convention, constitutional congress, or constitutional assembly) is a body assembled for the purpose of drafting or revising a constitution. Members of a constituent assembly may be elected by popular vote, drawn by sortition, appointed, or some combination of these methods. Assemblies are typically considered distinct from a regular legislature, although members of the legislature may compose a significant number or all of its members. As the fundamental document constituting a state, a constitution cannot normally be modified or amended by the state's normal legislative procedures in some jurisdictions; instead a constitutional convention or a constituent assembly, the rules for which are normally laid down in the constitution, must be set up. A constituent assembly is usually set up for its specific purpose, which it carries out in a relatively short time, after which the assembly is dissolved. A constituent assembly is a form of representative democracy.

Unlike forms of constitution-making in which a constitution is unilaterally imposed by a sovereign lawmaker, the constituent assembly creates a constitution through "internally imposed" actions, in that members of the constituent assembly are themselves citizens, but not necessarily the political leaders, of the country for which they are creating a constitution. As described by Columbia University Social Sciences Professor Jon Elster:

The term social mechanisms and mechanism-based explanations of social phenomena originate from the philosophy of science.

The core thinking behind the mechanism approach has been expressed as follows by Elster (1989: 3-4): “To explain an event is to give an account of why it happened. Usually… this takes the form of citing an earlier event as the cause of the event we want to explain…. [But] to cite the cause is not enough: the causal mechanism must also be provided, or at least suggested.”