 The existence of the city-state also requires an efficient cause, namely, its ruler. On Aristotle’s view, a community of any sort can possess order only if it has a ruling element or authority. This ruling principle is defined by the constitution, which sets criteria for political offices, particularly the sovereign office (III.6.1278b8–10; cf. IV.1.1289a15–18). However, on a deeper level, there must be an efficient cause to explain why a city-state acquires its constitution in the first place. Aristotle states that “the person who first established [the city-state] is the cause of very great benefits” (I.2.1253a30–1). This person was evidently the lawgiver (nomothetês), someone like Solon of Athens or Lycurgus of Sparta, who founded the constitution. Aristotle compares the lawgiver, or the politician more generally, to a craftsman (dêmiourgos) like a weaver or shipbuilder, who fashions material into a finished product (II.12.1273b32–3, VII.4.1325b40–1365a5).