Pope Leo XIV described himself as “a son of St. Augustine” when he greeted the faithful from the loggia of St. Peter’s Basilica for the first time on May 8, and he has already invoked St. Augustine too many times to count.

In an address to elected officials and civil servants from the French diocese of Creteil on August 28 – the feast of St. Augustine – Leo did not mention the great early 5^th century bishop of Hippo in Roman North Africa (and Doctor of the Church).

Nevertheless, Leo’s remarks were thoroughly Augustinian.

The men and women to whom Leo was speaking were Catholics on pilgrimage with their bishop, Dominique Blanchet, who had asked the pope to give the public servants some advice.

That, in itself, was noteworthy. France is demographically a majority Catholic country – indeed the French nation is known as fille aînée de l’Église, “the eldest daughter of the Church” – but France is also fiercely secular. The French constitutional principle of laïcité – literally “laity” but more closely rendered in English as “secularity” – creates and maintains not only a strict separation of Church and State but peculiar and stringent rules both written and unwritten regarding the role of faith in public and political life.

The advice Leo offered – speaking in French – was as follows: “[U]nite yourselves more and more to Jesus, to live by him and to bear witness to him.”

“There is no separation in the personality of a public figure,” Leo said, “there is not on one side the politician, on the other the Christian. But there is the politician who, under the gaze of God and his conscience, lives his commitments and responsibilities in a Christian way.”

Nor did Leo mince words when it came to laïcité. Noting that his guests were in Rome as pilgrims, Leo said, “This is why your initiative, more than just a personal enrichment, is of great importance and great utility for the men and women you serve.”

“It is all the more praiseworthy,” Leo continued, “because it is not easy in France, for an elected official, due to a laïcité that is sometimes misunderstood, to act and decide in accordance with his or her faith in the exercise of public responsibilities.”

In St. Augustine’s day – the last century of Roman rule in the western world – there was a reactionary party of pagan cultural elites in the empire, who argued that Christian religion was not compatible with the morals of a republic.

After the Visigoths – who for decades had been serving as Rome’s military force – sacked Rome in 410, the complaint of the pagans again gained some currency and eventually occasioned Augustine’s greatest work, On the City of God against the Pagans.

In a letter written in 412, St. Augustine wrote a nutshell version of his thesis.

“[L]et those who say that the doctrine of Christ is incompatible with the State’s well-being, give us an army composed of soldiers such as the doctrine of Christ requires them to be,” Augustine wrote.

“Let them give us such subjects, such husbands and wives, such parents and children, such masters and servants, such kings, such judges — in fine, even such taxpayers and tax-gatherers, as the Christian religion has taught that men should be, and then let them dare to say that it is adverse to the State’s well-being; yea, rather, let them no longer hesitate to confess that this doctrine, if it were obeyed, would be the salvation of the commonwealth,” the saint added.

Leo told the French public servants who were visiting him on pilgrimage that he is “well aware that the openly Christian commitment of a public official is not easy, particularly in certain Western societies where Christ and his Church are marginalized, often ignored, sometimes ridiculed.”

Leo acknowledged the “pressures, party orders, and ‘ideological colonizations’—to borrow a felicitous expression from  Pope Francis—to which politicians are subjected.”

“They need courage,” he said, “the courage to sometimes say ‘No, I cannot!’ when the truth is at stake.” When that happens, Leo said, there is only one thing for it: “Only union with Jesus – Jesus crucified! – will give you the courage to suffer for his name. He said to his disciples: ‘In the world you will suffer, but take courage! I have overcome the world’.”

In another speech on August 23, a few days before his address to the pilgrims of Creteil, Leo had made the Augustinian influence of his political thinking explicit.

“This Church Father taught that within human history, two ‘cities’ are intertwined: The City of Man and the City of God,” Leo told the International Catholic Legislators Network. “These signify spiritual realities – two orientations of the human heart and, therefore, of human civilization.”

“The City of Man,” Leo said, “built on pride and love of oneself, is marked by the pursuit of power, prestige and pleasure; the City of God, built on love of God unto selflessness, is characterized by justice, charity and humility.”

In St. Augustine’s view, the City of Man is not simply the prevailing political order, nor is the City of God simply the Church as she is on pilgrimage in history. Citizenship in the City of Man is incompatible with Citizenship in the City of God, but the temporal and spiritual orders do not directly correspond to the City of Man and the City of God.

While the temporal and spiritual orders are distinct, they are not separate in history.

In Augustine’s view – and Leo’s, too, it appears – being a member of the Church is not incompatible with responsible participation in the civil order of society or even in political life, though Christian commitments will always be in tension with social order generally, hence with politics, however organized and conducted.

As an Augustinian, Pope Leo XIV knows this even when he isn’t thinking about it.

If Leo’s remarks over the past days are any indication, he has been thinking about it a great deal.