Despite Covid and other unfavourable circumstances, the activities of the Pontifical Academy of Sciences have continued in recent years, under the great impetus of its President, Joachim von Braun, to whom we wish to thank and pay tribute, as well as to Council Member Veerabhadran Ramanathan, who organised this meeting with such skill and discipline. Papers and meetings of experts on ecology, food, paleo-anthropology, oceanography, building ecology, scientific publications, cultural events, in person and virtual presentations, as well as Council Meetings and new members, are a brilliant demonstration of the vitality of this institution, which is decisive for the common good of humanity.
The PAS is currently studying the highly specialised issue of ‘Resilience of people and ecosystems under climate stress’. As you can imagine, I will not go into the technical question, nor into the possibilities of its application. I prefer to stick to my studies and make a general consideration of virtuous attitudes that should guide resilience under the umbrella of sustainable development and climate stress.
Two attitudes for resilience
Let us highlight, in the more general field of scientific research on resilience, two attitudes that should characterise the scientist and the academic, and especially Christian scientists, or non-Christians who believe in the existence and providence of God.
On the one hand, scientists must honestly consider the question of the earthly future of humanity and of planet Earth, and, as responsible people, help to prepare for it, preserve it and eliminate the risks, in a resilient way, especially in the current situation of anthropic climate stress, wars, poverty, famine and threats of nuclear catastrophes.
I believe that this solidarity with present and future generations, properly understood, is a form of high charity and sincere love to which many human beings are sensitive today, within the framework of ecology. However, virtuous resilience with regard to this attitude must be ecological and not ecologist or, so to speak, “green”. Exaggerating, such can be called the vices of “doing nothing” (nihil agere), i.e., considering nature as a kind of museum where the muses live and dwell, a museum to be preserved and guarded by a custodian who merely cleans the masterpieces. Nor is this attitude, which we may call passive, the meaning of Haidegger’s imperative to “be custody of being”.
At the same time, therefore, the scientist must be animated by the confidence that nature holds secret potentialities which it is up to science, intelligence and human love to discover and put at the service of humanity, in order to achieve the project that is in the Creator’s mind. However, virtuous resilience with regard to this active attitude does not mean “doing just anything”. If in the first ecological attitude of “green solidarity” the mistake was in “doing nothing”, here the mistake is in doing without taking into account the real potential of nature and the work of human beings on it. In short, the virtuous attitude in resilience lies between two vicious extremes: that of doing nothing because it is considered that nature does not need the intervention of science, or that of considering nature as a material from which any development can be made to infinity, without taking into account its real potentiality and laws.
For a re-appropriation of act and potency
This leads me to consider resilience as an epistemic project and a form of truth, which can find a real foundation in the categories of being that Aristotle puts under the notions of potency and act. On the other hand, the IPCC definition of resilience uses the notion of capacity three times, i.e., “capacity of” a social system to absorb disturbances, “capacity for self-organisation”, “capacity to adapt to stress and change”. In short, the language of potency and action has not ceased to underlie the representation of human experience.
Aristotle observes in Metaphysics V [Δ] 12 and IX [θ] 1-10 that almost everything that falls under experience moves and changes; there is progress or return. Bodies change place and move in space; they change in magnitude and show increase or decrease in qualities, are destroyed or produced, i.e., begotten. In the living there is death and life, sleep and vigil; in those endowed with knowledge, ignorance and knowledge, memory and oblivion, etc.
From the analysis of these events Aristotle extracts the theory of act and potency, as the foundation of his whole philosophy, trying to solve the problems that had proved unsolvable to his predecessors, the Parmenidean physicists, and to Plato himself. Let’s imagine a statue of the god Mercury. There was a time when that wood or marble was not a statue or anything else with a shape; it became a statue, it received something in itself that it did not have before. Now, air or water are not statues either, nor do they have a stable shape. But neither can they have one: they are not susceptible of stable modification. Therefore, in the world of art and science some things are susceptible of artificial, stable and definite modification and others are not. Marble is not a statue, but it can become one. In the world of the living, the seed and the egg are not the oak or the chicken, but they can become them. An architect who is asleep does not build, but awake he can build.
Aristotle calls this capacity to act (or suffer) dynamis (δύναμις). The new reality in which the movement or development ends he calls act (ἐνέργεια). In this way, being as potency (beginning in IX [θ]1-5) allows us to include change within being, contrary to Parmenides’ prohibition. Because potentiality is a genuine mode of being, change, motion, and development are rightfully being. But when asked what sort of being is motion we are referred back to the dialectic definition of motion in the Physics, namely: ‘the fulfilment (ἐντελέχεια) of what exist potentially (τοῦ δυνάμει ὄντος), insofar as it exists potentially’. Aristotle thus succeeded in providing motion to a full-fledged ontological status, but at the cost of a real dialectical situation, for it is neither act nor potency separately but implies a certain coexistence of both, an act that still retains potency.
At this point it seems important to me to highlight a first corollary that emerges from this realist approach, which is valid for our theme of development and resilience: for there to be movement or development, it is necessary to start from a real power or capacity and not from a logical or purely relational one, as certain philosophers, economists or scientists claim, which does not take reality into account. In other words, this means that for there to be development and resilience, one must start from a natural reality or “ecological system” capable of having the potential to develop, or from a mind or “social system” that has science in act capable of producing development or resilience in nature. In this sense the philosophical dictum of Parmenides is fully valid, “from Nothing comes Nothing” (οὐδὲν ἐξ οὐδενός; ex nihilo nihil fit). If nothing can come out of nothing according to Parmenides, nothing can do so without a real power according to Aristotle: without a real principle there is no movement, no development, no resilience.
On the other hand, in the Aristotelian interpretation, the subsequent instance of change, movement or development is generally identified with the end (τέλος), which sometimes represents the final cause or that-for-which it was produced: ‘generation has as its object the end. And the actuality is the end, and it is for the sake of this that the potentiality is acquired; for animals do not see in order that they may have sight, but have sight in order that they may see. Similarly, men possess the art of building in order that they may build, and the power of speculation that they may speculate; they do not speculate in order that they may have the power of speculation’. The change, movement or development takes place not in view of potency but in view of the act, which is the goal of the action, the act having therefore absolute priority, and the capacity posteriority. When it is said that animals do not see in order to have sight, but that they have sight in order to see, just as the builder or the thinker has science for its exercise and not vice versa, it is being pointed out that capacity is considered as such insofar as it is capacity for something, capacity being thus a function of the end (act).
In the framework of globalisation and the existence of only one planet to house all human beings, the need for development to be “sustainable” fits well with this Aristotelian idea of a goal or end. The adjective ‘sustainable’ means that development is able to maintain the potential use of natural resources for the satisfaction of human needs, especially for future generations. Instead, in the context of human development and Sen and Nussbaum’s discussion of capabilities, an interpretation of the change in Aristotle would point out that their approach to capabilities lacks something: the consideration of actualisation as the end for which capabilities exist. In Sen’s approach, the goal of development is the expansion of human capabilities. However, since ‘animals do not see in order to see, but have sight in order to see’, the expansion of human capabilities is only desirable and valuable if it is directed towards the actualisation of those capabilities. In Aristotle, on the contrary, the goal is the human being’s happiness, which must be reached through the development of his or her capacities by means of the virtues. The mere expansion of one’s capacities does not produce the goal of happiness.
Difference within sustainable development and resilience
Let us now examine the difference between “sustainable development” and “resilience”. According to the Philosopher, in I De caelo, the word virtue refers to “the extreme limit of a power”. Natural power is, in a sense, a principle of action, as stated in V Metaphy., and in another sense, the “power of resisting corruptions”. And since the first meaning is more common, we have reserved the term virtue or potency for the principle of sustainable development in the sense that it is what enables development. But insofar as denoting the extreme limits of power, the sense of which is more specific, it is applied to a special attitude or principle, namely resilience, which means standing firm against all kinds of disturbances and stress.
Thus, the term resilience can be taken in two ways. Firstly, as if it simply denotes resistance in development. In this sense, it is something general, or rather a condition of all development, since it is a requirement of all development to resist steadfastly in one’s own movement. Secondly, and more pertinently, resilience can be seen as the wisdom and willingness to endure and sustain in those things where it is most difficult to be resilient and constant, i.e., in certain grave dangers such as global warming, war, famine and survival. Thus, the IPCC says resilience is “absorbing disturbances while retaining the same basic structure and ways of functioning, as well as self-organisation and adaptation to stress and change”.
For a resilient science project
Over and above the different verification procedures, there is a founding act in a place – Sicily and Athens – and at a time – the fifth century BC – that initiates the very project of science (episteme) as a form of truth. By organising the observation of nature through mathematics, geometry, the theory of proportions, and the criteria of form, number and measurement, this act finds its identification as the basis of a scientific project that has forever distinguished Western knowledge from any other. A chain of thought events, all random, and all necessary after the fact, have transformed this project into a destiny. It belongs to the notion of a thought event to create the irreversible. This is not the place to describe the historical chain of decisive discoveries that have since come down to us under this scientific project. C. Allègre limits himself to summarising the discoveries of the last century, starting with the computer, passing through biology (the DNA double helix), computer science, quantum mechanics, the chemical explosion (its formulation), astrophysics, the order of chaos (evolution), neurosciences, and finally the sciences of the atmosphere and climate. The common denominator is the idea of discovery as an organised form of the observation of nature. I would like to insist on the term nature. Indeed, it has enabled us to put mathematics back in its slot as a discipline of forms, numbers and relations as rational constructs pursued for themselves and not as constituting the science of reference. As C. Allègre writes, ‘contrary to the sciences of nature, mathematics does not develop by virtue of an oscillation between observation and theoretical model’ (p. 429). This is probably the reason for the perhaps controversial title – La défaite de Platon – he gave to his overview of science in the 20th century. With this scientific project what is at stake is the knowledge of what is real in nature. In this respect, the truth by observation of nature, with the asceticism of renouncing everything that is not number, figure, movement, delimits a sphere of truth that is obligatory, and it is the one to which all scientists conform. We believe that the scientist knows in part something that corresponds to the reality of nature. This partial correspondence between what science knows and the reality of nature is what we call scientific truth. And it is this truth that qualifies the relation of theory to reality in these sciences. For example, Pope Francis is convinced of the truth of the scientific community when he says ‘It is true that there are other factors (such as volcanic activity, variations in the Earth’s orbit and axis, the solar cycle), but several scientific studies indicate that most of the global warming of recent decades is due to the high concentration of greenhouse gases (carbon dioxide, methane, nitrogen oxides and others) released mainly by human activity’. And this truth of the epistemic project is a participation of Truth, which comes neither from philosophy nor from the sacred texts of religion. As a participation in the truth, the Church listens to science, seeks it, supports it and loves it.
Faced with the tragedies of global warming, inequality, hunger and war, today the scientific community is called upon to discover in nature, through thought and scientific project, those potentialities that God has placed in the natural creation in order to act on them for the salvation of the planet and future generations. It is the Hour of Resilience.
This hope in the Author of nature and in the human spirit, created in his image, properly understood, is capable of giving a new, serene energy to the researcher in general but, in particular, on the new path towards resilience.
 Aristot., Metaph., IX [θ], 8, 1048 a 31.
 Book IX [θ] begins with the idea of potency in its relation to movement and introduces act (actuality) only in chap. 6: ‘Actuality (ἐνέργεια) means the presence of the thing, not in the sense which we mean by potentially (δύναμις). We say that a thing is present potentially as Hermes is present in the wood, or the half-line in the whole, because it can be separated from it; and we even call a man who is not studying “a scholar” if he is capable of studying. That which is present in the opposite sense to this is present actually’ (Methap. ΙΧ [θ], 6, 1048 a 30-35). Recourse to induction and to analogy is added to this apparent circularity, for lack of direct definition: ‘What we mean can be plainly seen in the particular cases by induction; we need not seek a definition for every term, but must comprehend the analogy: that as that which is actually building is to that which is capable of building, so is that which is awake to that which is asleep; and that which is seeing to that which has the eyes shut, but has the power of sight; and that which is differentiated out of matter to the matter; and the finished article to the raw material. Let actuality be defined by one member of this antithesis, and the potential by the other’ (1048 a 35 – b 5).
 Aristot., Physica, ΙΙΙ [Γ], 1, 201 a 10 f.
 Aristot., Metaph. ΙΧ [θ], 8, 1050 a 5- 13.
 Nussbaum, M., Non‐Relative Virtues: An Aristotelian Approach, in M. Nussbaum, & A. Sen (Eds.), The Quality of Life, pp. 242-269, New York 1993.
 Τὸ κυρίως δυνατόν (De caelo, I, 11, 281 a 19 f.).
 Claude Allègre, La Défaite de Platon ou la science du XXe siècle, Fayard, Paris 1995.
 Laudato si’, § 23.