Pope Leo XIV: The Importance of Observing Natural Law

Natural law , as a universal principle inscribed in the very structure of the human being, represents an ethical compass that guides man towards good and truth . It is not a confessional construct nor an imposition of the Catholic Church reserved for its faithful, but an objective reality that transcends cultures, religions and times .

Living in ignorance of this law – or reducing it to a mere religious rule – is misleading and risks depriving humanity of an essential foundation for coexistence and moral progress . In this article we will highlight the importance of recognizing natural law, drawing on authoritative sources of philosophy , literature and religious tradition , until comparing it with the vision expressed by Pope Leo XIV in his speech of 21 June 2025 to parliamentarians from 68 countries, which will be reported in full below.

In particular, in his speech to parliamentarians from 68 countries, the Pope addressed numerous urgent issues of our time – from the protection of the common good , to religious freedom , to the challenge of artificial intelligence – but it is precisely the reference to natural law that stands out as the cornerstone of his speech, offering a unifying criterion for responding responsibly to the challenges of the present era.

Natural Law: A Universal Principle

Natural law is a norm intrinsic to man, recognizable through reason and conscience . Marcus Tullius Cicero , one of the greatest thinkers of antiquity, defines it in De Re Publica (III, 22) with illuminating words:

«There is a true law, right reason, in accordance with nature, universal, immutable and eternal, which invites to duty with its commands and deters from evil with its prohibitions. […] This law is not different in Rome or Athens, nor today or tomorrow, but is eternal and immutable, and governs all peoples in all times.»

Cicero emphasizes that natural law is not a human invention , but an immutable and universal reality, prior to positive laws and rooted in man's rational nature .

St. Thomas Aquinas , in the 13th century, explored the concept in depth in the Summa Theologiae (I-II, q. 91, a. 2), defining it:

«The participation of the eternal law in the rational creature.»

For Thomas, it is accessible to all , regardless of faith , since it springs from human reason enlightened by created nature :

"Natural law is imprinted on the soul of every man, so that he naturally knows what is good and what is evil."

Even outside of Christian thought, similar insights emerge. Confucius , in the Chinese tradition, speaks of a natural moral order, the li , which guides man towards harmony with the Tao (the universal way). In the Analects (15.24) he states:

"Do not do unto others what you would not want done unto you", a principle that recalls the golden rule contained in natural law.

The Error of Reducing Natural Law to a Religious Precept

To consider natural law as a confessional imposition is a serious misunderstanding . The Church does not invent this law: it recognizes it and promotes it as the common heritage of humanity .

Saint John Paul II , in the encyclical Veritatis Splendor (1993, n. 44), states:

«Natural law is nothing other than the light of the intellect infused into us by God. By it we know what we must do and what we must avoid.»

Reducing natural law to a religious norm means ignoring its rational and universal root. Living as if it did not exist leads to serious consequences:

• ethical relativism ,

• social fragmentation ,

• absence of a shared criterion for the common good .

The writer C.S. Lewis , in his essay The Abolition of Man (1943), warns:

«Man destroys himself by depriving himself of the criterion for distinguishing right from wrong», denying that universal principle that he himself defines as Tao .

Contemporary Perception and the Pope's Call: A Comparison

In today's world, dominated by relativism and individualism , the very idea of ​​natural law is often rejected or ignored . Personal freedom is exalted without constraint , and the concept of an objective moral principle is perceived as a threat , not as a guide .

In this context, crucial ethical issues – from the defense of life to bioethics, from family to artificial intelligence – are addressed without a shared reference , with polarizing and conflicting outcomes.

The speech of Pope Leo XIV , delivered on 21 June 2025 before parliamentarians from 68 countries, stands in stark contrast to this trend. In addition to recalling the urgency of promoting the common good , defending religious freedom and responsibly addressing the challenge of artificial intelligence , the Pope forcefully indicates natural law as the non-negotiable foundation of all political and social action. Quoting Cicero and linking this principle to the Universal Declaration of Human Rights (1948) , Leo XIV proposes a return to universal reason as the basis for global cooperation .

It is precisely this point – the reference to natural law – that emerges as the vital centre of his intervention, the key to responding truthfully to the challenges of our time.

Natural law: universal principle that guides man towards good through reason

As Cicero, Thomas Aquinas, Confucius , and others teach, natural law is a universal principle that guides man toward the good through reason . To ignore it or confine it to a religious precept is a mistake that undermines the foundations of civilization and justice .

The appeal of Pope Leo XIV is an invitation to rediscover it as a common heritage , capable of uniting peoples and cultures in an era marked by divisions and crises of meaning.

Note from the blog author The full speech of Pope Leo XIV , from which some quotes are taken, is available on the official Vatican website: www.vatican.va . I invite readers to meditate on it in light of what has been stated, to grasp the depth of a message that does not impose, but illuminates the path of man with the universal force of moral reason:

Audience with Parliamentarians on the occasion of the Jubilee of the Rulers, 06.21.2025

We publish below the speech that the Pope gave to those present during the meeting:

Madam President of the Council and Mr. President of the Chamber of Deputies of the Italian Republic, Madam President and Mr. Secretary General of the Inter-Parliamentary Union,

Representatives of Academic Institutions and Religious Leaders,

I am pleased to welcome you on the occasion of the Meeting of the International Inter-Parliamentary Union, in the Jubilee of Governors and Administrators. I greet the Members of the Delegations of sixty-eight countries. Among them, a special mention goes to the Presidents of the respective parliamentary institutions.

Political action was rightly defined by Pius XI as "the highest form of charity" (Pius XI, Address to the Italian Catholic University Federation, 18 December 1927). And in fact, if one considers the service it carries out for society and the common good, it truly appears as a work of that Christian love which is never a theory, but always a sign and concrete testimony of God's action in favour of man (cf. Francis, Encyclical Letter Fratelli tutti, 176-192).

I would therefore like to share with you this morning three considerations that I believe are important in the current cultural context.

The first concerns the task entrusted to you of promoting and protecting, beyond any particular interest, the good of the community, the common good, especially in defense of the weakest and most marginalized. For example, it means working to overcome the unacceptable disproportion between wealth possessed by a few and poverty that is widespread beyond measure (cf. Leo XIII, Encyclical Letter Rerum Novarum, 15 May 1891, 1). Those who live in extreme conditions cry out to make their voices heard and often find no ears willing to listen to them. This imbalance generates situations of permanent injustice, which easily result in violence and, sooner or later, in the tragedy of war. Good political action, on the other hand, by promoting the equitable distribution of resources, can offer an effective service to harmony and peace both at the social and international levels.

The second reflection concerns religious freedom and interreligious dialogue. Even in this field, which is increasingly topical today, political action can do much, promoting the conditions so that there is effective religious freedom and a respectful and constructive encounter between different religious communities can develop. Believing in God, with the positive values ​​that derive from it, is an immense source of good and truth in the life of individuals and communities. In this regard, Saint Augustine spoke of a passage of man from amor sui – selfish love for oneself, closed and destructive – to amor Dei – gratuitous love, which has its roots in God and which leads to the gift of self – , as a fundamental element in the construction of the civitas Dei , that is, of a society in which the fundamental law is charity (see De civitate Dei, XIV, 28).

In order to have a unitary point of reference in political action, rather than excluding a priori, in decision-making processes, the consideration of the transcendent, it will be useful to seek, in it, what unites everyone. To this end, an essential reference is that of natural law , not written by human hands, but recognized as universally valid and at all times , which finds in nature itself its most plausible and convincing form.

Cicero was already an authoritative interpreter of it in ancient times , writing in De re publica:

«Natural law is right reason, in conformity with nature, universal, constant and eternal, which by its commands invites to duty, by its prohibitions turns away from evil […]. It is not permitted to make any change to this law, nor to subtract any part, nor is it possible to abolish it altogether; nor can we free ourselves from it by means of the Senate or the people, nor is it necessary to seek a commentator or interpreter. And there will not be one law in Rome, one in Athens, one now, one hereafter; but one eternal and immutable law will govern all peoples in all times» (Cicero, De re publica, III, 22).

Natural law, universally valid beyond and above other beliefs of a more debatable nature, constitutes the compass with which to orient oneself in legislating and acting , in particular on delicate ethical questions that today are posed in a much more compelling manner than in the past, touching on the sphere of personal intimacy.

The Universal Declaration of Human Rights , approved and proclaimed by the United Nations on December 10, 1948, now belongs to the cultural heritage of humanity. That text, always current, can contribute significantly to placing the human person, in his inviolable integrity, at the foundation of the search for truth, to restore dignity to those who do not feel respected in their innermost being and in the demands of their conscience.

And we come to the third consideration. The level of civilization achieved in our world, and the objectives to which you are called to respond, today find a great challenge in artificial intelligence. This is a development that will certainly be of valid help to society, to the extent that, however, its use does not lead to undermining the identity and dignity of the human person and his fundamental freedoms.

In particular, we must not forget that artificial intelligence has its function in being a tool for the good of the human being, not to belittle it or to define its defeat. What is emerging, therefore, is a considerable challenge, which requires a lot of attention and a far-sighted look towards the future, to design, even in the context of new scenarios, healthy, fair and safe lifestyles, especially for the benefit of the younger generations.

Personal life is worth much more than an algorithm and social relationships require human spaces far beyond the limited schemes that any soulless machine can prepackage. Let us not forget that, despite being able to store millions of data and offer answers to many questions in a few seconds, artificial intelligence remains equipped with a static “memory” , in no way comparable to that of man and woman, which is instead creative, dynamic, generative , capable of uniting past, present and future in a lively and fruitful search for meaning , with all the ethical and existential implications that derive from it (see Francis, Speech to the G7 Session on Artificial Intelligence, 14 June 2024).

Politics cannot ignore a provocation of this magnitude. On the contrary, it is called into question, to respond to many citizens who rightly look, at the same time, with trust and concern at the challenges of this new digital culture.

On the occasion of the Jubilee of the Year 2000, Saint John Paul II pointed out to politicians Saint Thomas More as a witness to whom they could look and an intercessor under whose protection they could place their commitment. In fact, Sir Thomas More was a man faithful to his civil responsibilities, a perfect servant of the State precisely because of his faith, which led him to interpret politics not as a profession, but as a mission for the growth of truth and goodness. He "placed his public activity at the service of the person, especially if weak or poor; he managed social controversies with an exquisite sense of equity; he protected the family and defended it with strenuous commitment; he promoted the integral education of youth" (Apostolic Letter MP E Sancti Thomae Mori, 31 October 2000, 4). The courage with which he did not hesitate to sacrifice his own life rather than betray the truth makes him, for us, still today a martyr of freedom and the primacy of conscience. May his example also be a source of inspiration and planning for each of you.

Distinguished Ladies and Gentlemen, I thank you for this visit. I extend my best wishes for your commitment and I invoke heavenly blessings upon you and your loved ones.

Thank you all. God bless you and your work. Thank you.