ὁμολογοῦνται γὰρ τρεῖς εἶναι πολιτεῖαι παρὰ πᾶσιν ἀνθρώποις, τυραννὶς καὶ ὀλιγαρχία καὶ δημοκρατία· διοικοῦνται δ᾿ αἱ μὲν τυραννίδες καὶ ὀλιγαρχίαι τοῖς τρόποις τῶν ἐφεστηκότων, αἱ δὲ πόλεις αἱ δημοκρατούμεναι τοῖς νόμοις τοῖς κειμένοις.
It is acknowledged, namely, that there are in the world three forms of government, autocracy, oligarchy, and democracy: autocracies and oligarchies are administered according to the tempers of their lords, but democratic states according to established laws.
Aeschines, Against Timarchus (346/5 BC), I.4.