Pope John XXIII
Pacem in Terris §70
Pacem in Terris: On Establishing Universal Peace in Truth, Justice, Charity, and Liberty
70 There can be no doubt that a State juridical system which conforms to the principles of justice and rightness, and corresponds to the degree of civic maturity evinced by the State in question, is highly conducive to the attainment of the common good.
Source: Pacem in Terris (Vatican.va)