He is member of Vatican Observatory (Castelgandolfo). He has been professor of Philosophy of Nature in Universidad de Comillas (Madrid) and Physics and Astronomy at John Carroll University (Cleveland - U.S.A) During his 32 years as a teacher, he has imparted hundreds of lectures at many universities and cultural centre through Spain. He has been invited speaker at meetings on science, philosophy and theology in Spain, Italy and Colombia at the request of the Pontificial Institute of Culture and other national and international institutions.

the human person: nature, ethical and theological viewpoints

The concept of Person needs to be clearly established by philosophical considerations that go farther than the merely measurable parameters of the physical sciences. We use the term in everyday life and we seem to be clear about its meaning, even if we do not define it explicitly: a person is not a thing in the wide sense that includes mostly inanimate objects, but a living reality, thus implying a source of activity that is self-originated and that shows a spontaneity not found in the physical laws by themselves.

But this is just the first step. Nobody thinks of microbes, insects, fish or even other larger and marvelous living things as persons. While there is a common tendency to describe some animals –mostly in mythological or poetic terms- as fictional characters speaking and acting as we do, we do not take this seriously, except –perhaps- when regarding house pets or primates as basically so similar to ourselves that we uncritically attribute to them our own vices and virtues.

In our experience and common language we encounter persons, and describe them as such, only when we consider human beings. Something new is present in the way Man acts that is the common root of self-appreciation, culture (both in the sciences, the humanities, the different religions) and of the structure of society at all levels. This basic and universal root we call human rationality and thus we define Man as a Rational Animal.

A Person is thus defined by an activity in which ends are freely sought after being known as concepts (containing information that goes past the data of the senses), and valued as good. Rationalityis expressed and realized in the search for Truth, Beauty and Goodness, a multiple activity that corresponds to the two powers of the human spirit: intelligence and free will, to know and to love. Knowledge in this case is not a mere reaction to an external stimulus (this is the first source of our acquaintance with the world, through sense impressions), but a process where the data are consciously analyzed to obtain ideas of universal value, and inferences or deductions that apply to them well beyond the direct experience.The person is conscious of multiple possibilities, both of representing reality and of acting, and looks for the best explanation of facts and for the consequences of various courses of action, either as ends in themselves or as means to other ends. This leads to value judgments that embody purpose and free choice. Thus we apply to the person’s activity the categories of truth-error and of suitability and “goodness” that presuppose ends and means in acordance with the nature of things.

The philosophical concept of nature expresses the essence of a given reality in so far as it is the sufficient reason for its activities: acting should be tied to what the agent is. This is applied in science when we define matter –at any level- precisely by its form of interacting with other matter, including our laboratory instruments. An unnatural behavior has the connotation of error, it is something wrong and inappropriate, that is never found in the simple processes of the inanimate world, but that can be due -in the case of a person- to a free decision. In such a case we speak of right and wrong, the basis or moral judgments and of the concepts of rights and duties both at the personal level and also in the context of society.

Only Man, in our known Universe, has the power to know and choose in this way. While animals exhibit wonderful behavior, their acting cannot be attributed to a free choice arising from the conscious and free selection of alternative paths. A genetic program, coupled with conditioned responses from experience, rules animal activity. Consequently, no animal is bound by “duties” nor can it be the subject of corresponding rights, but we can be bound by duties towards animals even those that are not considered property of another human person.

Summing up: the human animal is“Person”because human activity includes newconcerns, due to intellectual powers and free will. By itself, intelligence is not a new way of acting but of knowing, and it is this new knowledge that should direct the free actions of the subject. Because the activity is not automatically predetermined, Man is held accountable for those free acts and is judged ethically good or evil. But the coexistence of biological conditioning and personal traits makes the human animal a profound mystery, frequently expressed in the terms of “the Mind-Body problem”, where the findings of different sciences have to be brought together into a satisfactory synthesis. We need to look at rationality –personhood- from different viewpoints to inquire about its origin and consequences, at the individual and the social level.

Inputs from the fields of Biology, Metaphyics, Ethics, Theology and History, will lead to a better understanding of how the concept of Person has been incorporated in different cultures, in codes of Law and in patterns of behavior. From Biology we should clarify the role of bodily structures, of genetic programming and conditioning,, of possible malfunctions at the organic level that will influence human behavior. From physical and metaphysical considerations we have to establish a logically sufficient reason for the traits that define a person, thus providing a basis for the concepts of rights and duties (human dignity and responsibility).

This will be clarified and extended by the theological ideas of personal relationships with a Creator who is also personal in nature, and both the first source of being and the final end that constitutes our eternal destiny.  How these ideas have in fact appeared in different cultures through human history should be taken into account as well, not to make our reasoning depend upon a kind of democratic consensus, but rather to see the limitations and even errors of restricted ways of thinking in merely natural terms. It is obvious that a complete development of this outline would require a very extensive treatment by different experts in all those fields, something clearly not possible within the limits of this essay.


We are part of the panoply of life forms at the animal level here on planet Earth, the only place where we have data and where scientific studies are possible. It is well established from biology that there is an intimate relationship among all living beings in the sense that all use the same set of aminoacids with the same chirality, the same cell size, the same basic chemistry in a liquid medium (carbon compounds in water). From the first cells of 3500 million years ago an unbroken process of development can be traced up to the present variety of orders, genres and species, culminating in the primate level that includes Man. Even if five great extinction events (some of astronomical origin) have eliminated perhaps 90% of all previous living forms, there are no indications of multiple starts from inanimate matter. The tree of life has lost many branches and has sprouted new ones, but there is only one trunk. Both the geological record and comparative anatomy support this view of a common origin and progressive development (evolution), even if many details have to be worked out to establish genetic descent and the concrete steps that led to each species.

The two key questions that cannot be answered in a scientific way by the available data concern the steps from inorganic material to the first living cell and from non-intelligent primates to Man. We are interested at this point in the second one: what is there that explains the difference between instinctive behavior (no matter how wonderful) and the new way of knowing that leads to purposeful and responsible acts, thus establishing the personal character of the human animal. Is it logically possible to say that organic evolution suffices to expect the emergence of intelligence and free will as the natural outcome of brain development and other anatomical changes? This is the hotly debated problem of Body and Mind, that we can clarify by accurately defining both terms with the methodology of the physical sciences and our own subjective experience.

The study of the material world begins with our sense reactions to external stimuli that impinge upon our sense organs. This implies a form of energy, understanding this term as the capacity to change in some way the state of a recipient (doing work). In fact, all of physics –from astronomy to chemistry and atomic theory- is the study of interactions ruled by conservation laws, the most basic of them being that in any material process there is never a creation from nothing nor a reduction to nothing, but only some change of a previous reality of the material world. The effect of material activity can only be found in something that will have material properties and that will be able, in turn, to cause further material interactions: from matter, one can only expect to obtain matter.

Modern science attributes all interactions to 4 “forces”: gravitational, electromagnetic, strong nuclear and weak nuclear. They have different intensities, ranges and outcomes, as well as the possibility of affecting only specific types of particles under concrete conditions. A common view that makes science possible as an objective description of the material world is stated as the “Cosmological Principle”: matter is the same everywhere in the Universe and it follows the same ways of acting under the same circumstances, so that the “Laws of Nature” are applicable everywhere and at all times. No cultural or personal conditionings or preferences will change the outcome of an experiment: human psychology has no influence outside the human person when we study the physical world. Scientific methodology requires that all processes be reproducible by any scientist using the correct experimental technique.

The only logical basis for this view is that human thought and free will cannot be considered as matter, endowed with the energies that cause the 4 interactions previously mentioned. This is also underlined by the obvious fact that neither can be measured in any experiment, since there are no parameters of mass, electrical charge, spin, wavelength, or anything else that physics uses to describe the components of matter.  And if we deal with a new reality that is immaterial, we have to admit a source for it that is also immaterial: a human spirit that cannot be the result of organic evolution, even if it is found after matter has evolved to the highest degree of structure and complexity in the human brain.

A new spiritual element in Man needs a creating Spirit, a Creator who with a free act determines when and where the first Man appears on Earth after evolution has prepared the suitable organic structure. We can infer the presence of this new element in the life chain from evidence of rationality in the assembly of complex tools, the decoration of instruments and caves, the burials that include offerings for a mysterious life beyond the grave. Once the organic basis is sufficiently developed to be joined to the spirit, it is out of the realm of science to decide if the first Man had to be only one or several, at one point on Earth or many. The biological compatibility of all humans presently on Earth is a persuasive argument towards the acceptance of a single origin, geographically and in time. We are thus led to the statement that all human beings on Earth share the same nature, belong to the same species, have the same basic abilities and are subjects of the same rights and duties. They are Persons in the full sense of the word, without distinction of color, race, or culture.

Our conscious identity implies the unity of subject for all processes, material and intellectual, so that body and soul –matter and spirit- form a single unit in a mysterious but undeniable whole, excluding any accidental dualism. The human Person has to include the totality of Man, with mutual conditioning between matter and spirit, but with end-products of two clearly distinct levels. Any attempt to reduce Man to just spirit or just matter is unacceptable when applied to our total experience.  Since our reasoning leads to a non-material (spiritual) reality as the source of thought and free will, we have the required reason for considering Man as a Person.

One rarely finds a denial of our body, but in some environments it seems logical to say that intelligence and free will can be explained in terms of electrical currents in the brain or quantum-mechanical effects in cellular structures. This is to reduce the real problem of sufficient reason to ways of detecting the presence of mental activity or of purposeful behavior. One cannot attribute the informational content of a TV show (interesting or boring) to the properties of the electrical currents in the receiver, or the poetic meaning of a literary work to the cellulose and ink of a book. The simple bending of an arm when I want is more important than the release of energy in the muscles and the leverage exerted by tendons and bones. The dependence upon a free decision excludes the deterministic process of simple physical forces, and the obvious fact that our will is not random but purposefulmakes its operations incompatible with the probabilistic fluctuations of quantum-mechanical systems.

We know ourselves, and the world, by experience, by reasoning from sense inputs, and by acquiring knowledge from others. We first become aware of our thinking and of bodily changes from interactions between sense organs and “forces” in our surroundings. When the senses perceive and quantify inputs beyond their normal range of responses –with the help of instruments- we enter into the methodology of “science”, as applied to the properties and interactions of matter.

Intelligence looks for relations of cause, order (Beauty) and desirability (Goodness) in the data. This implies the use of the principles of identity, non contradiction and sufficient reason, that necessarily underlie all aspects of rational thought, be it in the development of science or in philosophy or theology.  From the principle of identity we derive the constancy of behavior in non-living matter: things are what they are, and their properties determine their activity, thus supporting the objectivity and constancy of the laws of nature.  The principle of non-contradiction requires self-consistency and the absence of absurd consequences in any reasoning process, so that in pure Math the only criterion of correct deductions is that they do not lead to a contradiction in their development or necessary consequences.

The search for a sufficient reason leads to hypothesis that should be examined in their theoretical sources, their logical consequences, and in the actual experimental checks when these are possible. We never accept as a sufficient reason a “just because” that doesn’t satisfy even a small child. This is frequently the real meaning of attributing to “chance” a physical result for which we have no known cause, as is the case when we try to establish a relationship between events that really have no logical connection. We should remember that chance is not experimentally measurable, it is not a parameter of any elementary particle or material structure, it can never be the cause of any event, and still less of order at any level.

The innate desire to find order in our knowledge is expressed in the search for patterns –physical or conceptual- where one finds the special satisfaction that we express with the general word beauty or harmony. It can be the simplicity and power of a mathematical expression or a generalized understanding of diverse aspects of nature previously unconnected in our experience: we can appreciate the beauty of the Law of Gravitation, applying to common objects, to planets and galaxies, and expressed with a simple equation by Newton. It is not uncommon for scientists to judge a hypothesis or theory in terms of its beauty: it introduces nothing superfluous or contrived or, on the contrary, seems cumbersome and arbitrary.

The same is true in the world of nature or art: combinations of shapes, volumes, lines and colors can give the pleasure of balance, proportion, contrast, gradual development, even just marvelous complexity at the microscopic level or overwhelming majesty in the grandeur of the heavens. It has been said that science develops from the sense of wonder that the thinking person cannot avoid feeling when studying nature at all levels. And it is well known that cave Man left paintings of great skill and beauty, as well as carvings and even primitive musical instruments: activities that have no relationship with mere survival or other practical concerns. They might have been considered of some magical value, but this is precisely the new “spiritual” aspect of human activity that includes symbols and concepts that are not found in any other species in the living world.

The search for Goodness is due to a value judgment regarding the suitability of some action to obtain a desirable end. Anything that is consonant with our needs, either at the biological or spiritual level, constitutes a good, from survival (which includes food, shelter, rest) to the fulfillment of our desire for affection, companionship and even knowledge and beauty, can be classified as a good that attracts and leads to activities ordered to obtain it. Whether those activities are consonant with human dignity –of the subject and of others- or opposed to it, determines the ethical value of an action.


Since the human person has some activities of a private order, while others impinge upon other members of the human family, the way human activity is subjected to norms and value judgments will address the question of what is consonant with human nature at both levels.

The development of rationality requires the constant search for Truth: no responsible decision can be based on wrong knowledge. This implies rights and duties concerning education, beginning with the family and continued at higher levels, made possible by society, not to impose any “brain washing” but to open all legitimate avenues of learning.  Professional activities require competence that has to be acquired by learning in the proper institutions, and that then implies the right to compensation for services in any field.

The right to the necessary sustenance, to health care, to housing and work opportunities, will also be a consequence of the need to develop the individual, both physically and culturally. Society needs laws that ensure that this is the case for all citizens. International bodies are legitimately entitled to regulate commerce, travel, exchange of information, in order to achieve equal opportunities for everybody. Echoing Pope John Paul II at the UN, “society is for the individual, not the other way around”.

This is stated in the Declaration of Human Rights signed by members of the UN in 1948. These rights are not due to some concession by any kind of government, and they cannot be legitimally abrogated or conculcated. Because those rights are rooted on the very nature of the human person, they have to be respected at any stage of natural life, from conception to death, even if age, sickness or genetic disabilities make the full use of intelligence and free will impossible in some cases or circumstances.

The Person can never be reduced to the level of a “thing” to be manipulated or disposed of for economic or scientific reasons. This is especially relevant in the fields of Medicine or Biology: no treatment can be allowed for any other purpose than the good of the patient. Laws that ignore this norm cannot be legally binding, but must be resisted and repelled.

Because ethical considerations flow necessarily from the sense of dignity and responsibility of an intelligent subject, this aspect of human life must be present from the very moment that Man appears on Earth. Primitive burials are a clear sign of the conviction that other humans are different from animals and that somehow their existence after death must be helped by rites and objects that must accompany the deceased. The evidence of protracted care for the sick (for instance, when people subjected to a trepanning of the skull lived long enough for the bone to heal and close the opening) is another indication of family and social ties that imply a common feeling of dependence and duties for those unable to survive by themselves.

Still, in a primitive world where small groups lived in almost total isolation from other tribes, ethical norms developed in many different ways. Science, philosophy, art and ethical norms, form human culture, that is not inherited genetically, but transmitted by signs, endowed -arbitrarily and freely- with meaning: sounds (speech), visible forms (writing, comprehensible images) or gestures that convey information, a new category not found by any experiment. Because cultures evolved independently, different places and times gave rise to codes of ethics and laws that –in many cases- contradicted each other.

We can simply mention how all over the world we find indications of past slavery,, caste systems, denials of rights to women and children, human sacrifices, war as the common state of confrontation with nearby groups. But this kind of behavior is akin to the modern control of the individual by totalitarian regimes (Nazi Germany, Communist societies) and it is necessary to state that a significant number of signatories of the UN “Declaration of Human Rights” still fail to comply with the solemn compromise accepted in 1948. In those the human Person is rather considered only as a productive element for the impersonal State, and it is subjected to a control that restricts even the most basic rights of education, work, marriage and free movement, the practice of religion and association for legitimate ends.

In modern times, where the constant exchange of information and world-wide travel tend to create a uniform way of life, the final outcome of such contacts might lead to a common “culture” where the individual is led to think that whatever others do is correct for everybody. An implicit “relativism” will finally deny that there are ethical norms that arise from human nature itself and that anything that is not forbidden by law is morally acceptable.  This is the underlying justification for abortion, euthanasia, genetic manipulation: instances where the person is degraded to the level of laboratory guinea pigs, useful as “things” to be manipulated for the benefit of others or destroyed when they become cumbersome and unprofitable for society.

A common statement that expresses this attitude is that “all cultures are equally to be respected”. If the word “culture” is not defined, the statement is meaningless: it can mean the way a group builds homes or entertains their citizens with music and dances. The most basic meaning should rather be the “system of common ideas that structure a given society”. Those ideas should determine personal and social behavior, thus being incorporated into codes of law, administrative and practical structures, rules of personal behavior. Over the course of time, the “way of life” transmitted from one generation to another within a human group, can also be termed a “culture” in so far as it incorporates commonly held values and concerns.

But the appreciation of a culture cannot simply rest upon its existence through a short or long time. If the culture leads to the denial of human rights to any kind of member of the group, or it incorporates a negative and hostile attitude toward other groups, the culture has no right to be respected and preserved. We must remember again and again that the human person is the subject of rights and duties by the dignity that is rooted upon the unique power to think and act freely. No external imposition can legitimately deprive a single person of what nature implies. Even civil disobedience might become a moral duty, no matter what the consequences, when moral good and evil are concerned.

One should also mention that the right of every person to have access to education, health care, modern developments of a kind that improves substantially human life, should take precedence upon considerations of an egotistical nature even if they seem to be justified by the desire to maintain primitive tribes in their original state to allow for their scientific study. To deny to a sick child the life saving attention that it needs and the opportunity to learn and develop fully as a human being is not acceptable from the moral viewpoint, either in a slum of a modern city or in the jungle of the heart of Africa. We might be unable to provide that help everywhere, but it should be our impossibility and nor a false respect for a primitive culture the deciding factor.

Governments everywhere have the duty to eradicate every type of exploitation of the weak and poor, be it through some kind of slave labor or its equivalent, or the demeaning traffic of drugs and prostitution, or racial and religious intolerance. The human person –every person- is the highest value we find on Earth.

Global concerns –about climate, overpopulation, famine, migration – are clearly in need of ethical rules that should look at the good of the persons affected, now and in the future, but destroying lives or condemning undeveloped nations to hunger and ignorance cannot be an option. The resources of our planet are more than sufficient to give every human being a level of nutrition, housing, education and medical care suitable for human dignity.


The human spirit, created by a Personal Creator, intelligent and free, appears as the apex of the development of the Universe. The Anthropic coincidences, at the very first instant of the Big Bang, can only be explained by a purposeful plan of the Creator to establish a meaningful relationship with personal beings. To invoke for their existence either a childish ”just because”, or to have recourse to chance within an unverifiable multitude of universes, is unscientific and totally empty of explanatory power. On the other hand, an intelligent and infinite Creator will not act without a purpose, and this cannot be an empty desire to watch how stars burn or lizards scurry over a planet. A Person is not satisfied with anything less than other persons.

This means that the “deistic” God accepted by some scientists as the final reason “why there is something instead of nothing” ends up by being absurd. Such a Supreme Creator would create a marvelous Universe just as a banal exercise of omnipotence, without caring for the persons who are able to reason to a First Cause and to be grateful for their existence. This is still more absurd if we extrapolate the evolution of the Universe to remote future ages when all the stars will be dead cinders and no life can survive anywhere.

In some Eastern philosophies, the final state implies the dissolution of individual persons into an undiferentiated “something”, not truly divine in a transcendent sense, where personal identity is lost. This is philosophically untenable and incompatible with the true idea of a Creator who is always infinitely superior and different from any creature: one cannot take seriously the proposal that finite and infinite will become an undifferentiated  mixture and that the very notion of person will no longer be applicable.
The same can be said of the recycling of human beings through reincarnations where the distinction between persons and animals is erased. And the final state, after the supposed purification attained in those reincarnations is described once more as the cessation of personal existence and activity.

In the Christian Creed, God is confessed as a Trinity, where the concept of Person surpasses our philosophical intuitions by presenting a unique Nature realized in three distinct Persons, with only one intelligence and will, so necessarily related that no single Person can exist or be described without reference to the other two. Thus the unicity of the Divinity is insisted upon, while stressing the divine life as a total and necessary communication of the entire nature from the Father to the Son and from both to the Holy Spirit. We cannot understand this, but we cannot understand matter either, when we try to reconcile the particle-wave duality into a single picture of elementary units of everyday matter.

No human philosophy or poetic effort could have imagined the Trinity, and we can only accept it through a Revelation that was not present in the Old Testament books of the Bible but that was gradually uncovered in the teachings of the New Testament. As we develop Theology –the effort to understand the revealed truths- we come to appreciate the depth of this mystery where the most intimate nature of the Godhead, while still incomprehensible, appears as the logical source of God’s relationship to humankind. If in the creation of finite spirits (angels) God can be said to seek living images of the divine nature, endowed with intelligence and free will and existing without constraints of space and time, their perfectly simple nature is so completely indivisible and self-contained that the communication of life –the very essence of the Trinity- cannot be shared by the created beings. They are incomplete images of the living God in that respect.

The creation of matter does provide the possibility of finding complex structures that can give part of themselves as a seed for new members of the species. But matter cannot have intelligence and free will, thus precluding the existence of Persons within the realm of pure matter. Without those attributes, there can be no meaningful relationship with the Creator.

The further step of joining matter and spirit in Man does achieve the complete image of God as a reality endowed with intelligence, free will and the ability to communicate life. Thus we find the description of the origin of Man in the poetic language of Genesis. Everything leads to the masterpiece of divine power, an Image and Likeness of the Creator, destined to share the divine happiness in a final state of intimate knowledge and love, outside the limits of space and time.

The Incarnation adds another mystery regarding the concept of Person, while underlining the infinite love of God and the dignity of Man. Christ, as God-Man, is adored as God, while being true Man, with soul and body on a par with ours. But we profess only one Person, divine, as the ultimate subject of activity and attribution, so that human activities are attributed to God and divine activities to the Man Jesus. Again, we cannot truly understand the mystery, but we can say that God has entered the human family, and that no greater glory can be imagined for any possible created being than to have God as brother.

It is true that we cannot do more than to accept a mystery that has baffled the best minds through the centuries, giving rise to all kinds of efforts to avoid the true divinity of Christ or to attribute to his humanity a nature that ultimately would deny his common descent from other human members of our race. Councils and Church Fathers were adamant in their insistence on the dual nature of Christ in the unity of a divine Person. Only thus could the reality of the Incarnation and Redemption be truly maintained.

Christ’s Resurrection is the final act of the saving and transforming plan of God for all mankind. A divine Person, with a body taken from the ashes of stars that formed our Earth and with a human mind and will, encompasses all levels of existence and carries our human nature to the intimate essence of the Godhead as the first fruits of the new kind of life that God wants for all of us. As individual persons, we are destined to exist forever, attaining the fullness of life with unlimited knowledge satisfying our minds and infinite love giving us the happiness proper of God in an unchanging eternity. The incredible variety of each human being through all of history will be a galaxy of lights, each different in a unique way of reflecting the perfection of the Creator, thus expressing as persons the multiple ways of sharing in the generosity of the Father from whom all good things come.

In terms of physical laws, the future of the Universe, with its predictable final state of emptiness, darkness and cold, seems to make its existence pointless, and the fact of the creation by God so that human persons will appear would no longer seem its sufficient reason. The only answer to the apparent absurd could be found in the immortality of the human spirit, not tied to the laws of physics by its very nature. But Theology goes farther, asserting for the human Person, body and soul, this new life inchoated by Christ’s resurrection and promised to all those who are joined to Him in a new kind of activity that is proper to God alone and that will be shared outside the limits of space and time.

Only in Christian Theology, based upon clear concepts of God and Man, of matter and spirit, is the unique dignity of each Person conserved.