*Aristotle is credited with works on the constitutions of 158 states: a papyrus containing all but the opening few pages of the Athenian constitution was acquired by the British Museum, and was published in 1891. About the first two thirds (chs. 1–41) give a history of the constitution to the restoration of the democracy after the regime of the Thirty (see thirty tyrants). This part derives from a mixture of sources, and is of uneven merit, but at its best it contains valuable information which does not survive in any other text. The remaining third (42–69) gives an extremely useful account of the working of the constitution in the author's time, and appears to be based on the laws of Athens and the author's own observation.There has been much argument as to the authorship of the work: it was regularly attributed in antiquity to Aristotle, and was written (in the 330s bce, with some revision in the 320s) when he was in Athens; there are some striking agreements between the Athēnaiōn politeia and Aristotle's Politics (e.