As Paul Ricœur said, quoted in Laudato Si’: “I express myself in expressing the world; in my effort to decipher the sacredness of the world, I explore my own”.Footnote 1 Indeed, in this dialectic of self-recognition in relation to other beings, Christian philosophy states that the human soul—which is a “subsistent form inseparable from the act of being” (actus essendi), capable of knowing and loving, i.e. spirit,—although being a substantial form of the body, is intrinsically incorruptible in the real order of things. This is the metaphysical foundation, according to which the human person is in himself free and capable of ethical order, and emerges from the forces of nature and the instincts of animals.Footnote 2 As a spiritual subject, the human being is imago Dei and capable of “receiving grace”, i.e. to be a child of God, and this is the highest status and dignity that a human being can reach as a spiritual being. Hence, “when the human being has received grace, he is capable of performing the required acts” for himself and others.Footnote 3 In this sense, I think, like most people, that robots cannot be considered as persons, so robots will not and should not possess freedom and do not possess a spiritual soul and cannot be considered “images of God”. AI and robots are beings invented by humans to be their instruments for the good of human society.

Christian philosophy distinguishes two types of cause, principal and instrumental. The principal cause works by the power of its entity, to which entity the effect is likened, just as fire by its own heat makes something hot. But the instrumental cause works not by the power of its entity, but only by the motion whereby it is moved by the principal agent: so that the effect is not likened to the instrument but to the principal agent: for instance, the bed is not like the axe, but like the art which is in the craftsman’s mind. Now such power is proportionate to the instrument. And consequently it stands in comparison to the complete and perfect power of anything, as the instrument to the principal agent. For an instrument does not work save as moved by the principal agent, which works of itself. And therefore the power of the principal agent exists in nature completely and perfectly, whereas the instrumental power has a being that passes from one thing into another, and is incomplete.

So, an instrument has a twofold action: one is instrumental, in respect of which it works not by its own power but by the power of the principal agent; the other is its proper action, which belongs to it in respect of its proper entity. Thus, it belongs to an axe to cut asunder by reason of its sharpness, but not to make a bed, in so far as it is the instrument of an art. But it does not accomplish the instrumental action save by exercising its proper action, for it is by cutting that it makes a bed.

St. Thomas calls the action of the principal agent as soon as it “flows” into the instrument “intentional” and has an incomplete energy and existence from one subject to another, similar to the passage from the agent to the patient.Footnote 4

Aristotle speaks of two types of instruments: ἔμψυχον ὄργανον (living tool), and ὄργανον ἄψυχος (inanimate tool). The first is like the servant who moves by the will of his owner, the other as the axe.Footnote 5 The Philosopher makes another rather minor distinction in his text but one that has been a source of inspiration for Christian theology: “These considerations therefore make clear the nature of the slave and his essential quality: one who is a human being belonging by nature not to himself but to another is by nature a slave, and a person is a human being belonging to another if being a man he is an article of property, and an article of property is an instrument for action separable from its owner (ὄργανον πρακτικὸν καὶ χωριστόν)”.Footnote 6 St. Thomas comments: “Then, supposedly such a definition of the servant, he concludes: the servant is an animated organ separated from another existing man [...]. In fact, it is said separate to distinguish it from another part that is not separated, like the hand”.Footnote 7 Inspired by this suggestion, Christian theologians distinguish between the united instrument (instrumentum coniuctum) such one’s own arm and hand, and the separate instrument (instrumentum separatum) such as the pen, the crosier, the cane, or the car: “Gubernator enim gubernat manu, et temone: manus enim est instrumentum coniunctum, cuius forma est anima. Unde temo est instrumentum movens navem, et motum a manu; sed manus non est instrumentum motum ab aliquo exteriori, sed solum a principio intrinseco: est enim pars hominis moventis seipsum”.Footnote 8

This distinction between separate and united instruments has a major role starting with the doctrine of St. John Damascene who considers the humanity of Christ an “instrument of divinity” (ὄργανον τῆς Θειοτἠτος).Footnote 9 St. Thomas with explicit reference to this profound indication of St John Damascene states, “Christ’s humanity is an ‘organ of His Godhead,’ as Damascene says. Now an instrument does not bring forth the action of the principal agent by its own power, but in virtue of the principal agent. Hence Christ’s humanity does not cause grace by its own power, but by virtue of the Divine Nature joined to it, whereby the actions of Christ’s humanity are saving actions”.Footnote 10 Moreover, the Angelic Doctor affirms in one of his last texts that the main cause of grace is God Himself; Christ’s humanity, on the contrary, is the instrument linked to divinity, while the sacraments are separate instruments. Indeed: “a sacrament in causing grace works after the manner of an instrument. Now an instrument is twofold: the one, separate, as a stick, for instance; the other, united, as a hand. Moreover, the separate instrument is moved by means of the united instrument, as a stick by the hand. Now the principal efficient cause of grace is God Himself, in comparison with Whom Christ’s humanity is as a united instrument, whereas the sacrament is as a separate instrument. Consequently, the saving power must be derived by the sacraments from Christ’s Godhead through His humanity”.Footnote 11

As can be deduced by these quotations, the term “instrument” is used in various senses, but with reference to one central idea and one definite characteristic, and not as merely a common epithet. Now of all these senses which “instrument” has, the primary sense is clearly that of not being a cause of itself or not existing by itself as an instrument. On the contrary, in a famous text Aristotle defines being free as the one that is a cause of himself or exists on its own and for himself, i.e. one who is cause of himself (causa sui or causa sui ipsius). In fact: “we call a man free who exists for himself and not for another (ἄνθρωπος, φαμέν, ἐλεύθερος ὁ αὑτοῦ ἕνεκα καὶ μὴ ἄλλου ὤν)”.Footnote 12

As I said at the beginning, for a being to be free and a cause of himself, it is necessary that he/she be a person endowed with a spiritual soul, on which his or her cognitive and volitional activity is based. AI and robots are just that: an artificial reality and not a natural reality, that is, invented by the human being to fulfil a purpose imposed by the human being. It can become a very perfect reality that performs operations in quantity and quality more precisely than a human being, but as an AI or robot it cannot choose for itself a different purpose from what the human being programmed it for. It can be hypothesized that there are robots composed of organic parts of animals (which Aristotle calls living tools) and inanimate parts that perform mathematical operations following algorithms that for humans are almost impossible to fulfil, but these entities will never be ends for themselves, but means at the service of humans.

The fact that AI and robots are instruments without a spiritual soul does not prevent them from being able to transmit a spiritual virtuality, “as thus in the very voice which is perceived by the senses there is a certain spiritual power, inasmuch as it proceeds from a mental concept, of arousing the mind of the hearer”.Footnote 13 A corollary of this may be when Aristotle says, “all these instruments it is true are benefited by the persons who use them, but there can be no friendship, nor justice, towards inanimate things; indeed not even towards a horse or an ox, nor yet towards a slave as slave. For master and slave have nothing in common: a slave is a living tool, just as a tool is an inanimate slave. Therefore there can be no friendship with a slave as slave, though there can be as human being: for there seems to be some room for justice in the relations of every human being with every other that is capable of participating in law and contract, and hence friendship also is possible with everyone so far as he is a human being. Hence even in tyrannies there is but little scope for friendship and justice between ruler and subjects; but there is most room for them in democracies, where the citizens being equal have many things in common”.Footnote 14

Laudato Si’, criticizing the prevailing technological paradigm, warns us that today it seems inconceivable to use technology as a mere instrument. “The technological paradigm has become so dominant that it would be difficult to do without its resources and even more difficult to utilize them without being dominated by their internal logic. It has become countercultural to choose a lifestyle whose goals are even partly independent of technology, of its costs and its power to globalize and make us all the same. Technology tends to absorb everything into its ironclad logic, and those who are surrounded with technology ‘know full well that it moves forward in the final analysis neither for profit nor for the well-being of the human race’, that ‘in the most radical sense of the term power is its motive—a lordship over all’.Footnote 15 As a result, ‘man seizes hold of the naked elements of both nature and human nature’.Footnote 16 Our capacity to make decisions, a more genuine freedom and the space for each one’s alternative creativity are diminished”.

We need to help remedy this profound crisis, caused by a confusion of our moral visions, of ends and means. We need to help stop this technological paradigm that is leading the world towards disaster. We must recognize human life itself, with its dignity and freedom, and we must work for the survival of our planet. “If a man gains the whole world but loses his soul, what benefit does he obtain?” (Matt 16:26). Yes, we are facing a matter of calculation, the calculation to save our world from indifference and from the idolatry of power of this technological paradigm. This is what Jesus meant when he told us that the poor in spirit, the gentle, those whose hearts desire justice, those who are merciful, those whose hearts are pure are Felices or Bienaventurados, happy and blessed, for theirs is the kingdom of heaven.

We need thinkers and practitioners who know how to use artificial intelligence and robots to alleviate suffering, to operate justice, to realize the highest good of peace. We thus welcome thinkers and practitioners who are capable of thinking and using these extraordinary tools for the sustainable development of the human being.