Pope John XXIII
Pacem in Terris §29
Pacem in Terris: On Establishing Universal Peace in Truth, Justice, Charity, and Liberty
29 Thus, for example, the right to live involves the duty to preserve one's life; the right to a decent standard of living, the duty to live in a becoming fashion; the right to be free to seek out the truth, the duty to devote oneself to an ever deeper and wider search for it.
Source: Pacem in Terris (Vatican.va)