resources_nature_interests_Is the notion of the soul obsolete?

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resources_nature_txt_Is the notion of the soul obsolete?

Has the notion of the soul become obsolete?

Author: Santiago Collado
Published in: F.J. Soler Gil - M. Alfonseca (coords.), "60 questions on science and faith answered by 26 university professors". Madrid: Stella maris, pp. 169-75.
Date of publication: 2014

Notion of the soul

Observation of the natural world led classical Greek thinkers to distinguish at least two modes of being whose difference was for them very clear. On the one hand, living beings, which exhibit a subject of movements and properties not found in other physical beings. Living beings, for example, are conceived and come into being at an easily identifiable moment; living beings are not made or fabricated, as are artefacts, which require direct or indirect human intervention and a process that unfolds over time until the artefact can be said to have been made. Living things, on the other hand, do not require human intervention to come into existence and grow in a way that is unique to the living. It is they themselves who procure, by feeding themselves, the materials they need to grow. The living being does not grow because elements are added to it from outside, but because it incorporates them itself so that they become part of its organism.

A building is constructed, an artefact is manufactured. We can say that we have the building or the artefact when its manufacture is finished. It takes some time from the beginning of the construction of a building until it is ready for the keys to be handed over to the corresponding owners at submit .

A living being, on the other hand, is conceived and is a living being from the very moment it is conceived. While a being is alive, it incorporates materials from outside and uses them to grow. It is as if its construction were equivalent to its being alive. Unlike what happens with what is not alive, when movements such as growing or feeding stop, when that body ceases to form, when death occurs, that living being ceases to exist. It is as if, when a building ceases to be built, it collapses.

In nature we can also find systems or beings that are not alive and that can grow: a swamp, a cloud, a crystal, a snowflake, etc. In these cases growth is associated with an increase in size. In the case of living things, growth can also be associated with an increase in size, but it means much more. For a living being, growth implies, primarily, an organic differentiation that takes place from agreement with a unit. Growing implies incorporating new materials into the organism, which requires a unity that is not broken by such incorporation, but rather strengthened.

Being born, growing, reproducing, feeding and dying are considered by the Aristotelian tradition to be exclusive movements of living beings. These movements, in turn, are carried out in different ways and at different levels. We can distinguish between the vital movements of plants and those of animals, for example.

What is it that makes a living being able to carry out this subject of movements or operations? The Greek thinkers considered that it was due to the subject unity that the living being manifests. As long as this unity is maintained, the animal can exercise its characteristic operations or functions. This vital unity is what the classics called the soul. We know that a being is animate, that it has a soul, when it is alive, when it is capable of performing the operations characteristic of animals or plants.

A living being dies when it loses its characteristic unity. Then its body is corrupted, disintegrated. At the moment of death it has all the material elements that formed its body when it was still alive, but it can no longer do anything of what it did then: it has lost its unity, or in other words, it lacks its soul, it has died. On the other hand, we will never say of a stone or an artefact, even if it breaks, that it is dead. This can be said in a metaphorical sense, but not in a real and proper sense.

Human soul

The Greeks also considered the human being as a very peculiar living being. His soul, the peculiar subject of unity that he possesses, enables him to perform operations that no other living being can perform. In the classical terminology , animals are said to be able to see because they have a School, sight, which enables them to perform the corresponding operations. Understanding and will are the names given to the Schools associated with the human capacity to think and will.

Aristotle considered human intelligence to be so extraordinary that he saw in it a glimpse of divine intelligence. The properties which made men distinct from other living beings were considered to be the expression of a principle which transcends the unity of the organic, although it is also its cause. We call this principle spirit. Philosophical reflection therefore found reasons to affirm that the human soul is not only an expression of the peculiar vital unity of the human body, as is the case with the rest of the animals, but that it is also the principle of others Schools exclusive to it, which seem to go beyond what the purely organic can give of itself: symbolic language, culture, mathematics, etc. This is why, when we refer to man, it is more appropriate to say spiritual soul. It is not that the spirit is superimposed on the soul, understood as a vital unit, but that the human soul, by granting the capacity to exercise such peculiar operations, manifests its difference with respect to other types of life. We cannot dwell here on the scope and implications of what we know as the human spirit or spirit soul.

Christianity reinforced this idea of the transcendence of the spirit on subject by giving the word spirit a richer and more precise meaning. Man is called to immortality, to communion with God, who is eternal. By his mode of being, man is the only living being with a material body, and therefore mortal, who can address God by treating him as another self, and who is destined to participate in the divine life itself.

Cartesian dualism

The problem introduced by Cartesian rationalism consists, basically, in the identification of the soul with the spirit. Descartes disregards the peculiarity that the classics and the Middle Ages had noticed in the unity of the living. This neglect has important consequences for the understanding of nature and man. Descartes equates, for example, animals with machines: animals are very complex machines. But understanding life in this way also leads to the view that man, as a corporeal being, as an animal, is also a particularly complex machine. In order to explain the cause of his unique intellectual capacities, one must admit a principle of a completely different nature from the corporeal one, which controls it from outside. Descartes has a dualistic way of thinking about man. He conceives him as the union of two substances completely different in their way of being, but in which the spiritual part, like a pilot, directs the body, the vessel which the spirit uses to intervene in the material world.

From this perspective, the non-human living being is a machine without a soul. But if to say soul is to say spirit, it is not possible to distinguish, except in man, what is living from what is not. The distinction will then be in the issue of elements that make up the living being and the Degree complexity of the relationships between them.

The human being is then understood as a machine connected in some way with a spirit. The soul - spirit - then possesses its own existence independent of the body. Body and soul would be united in a way that, in classical terms, could be called accidental. Strictly speaking, spirit and body do not require each other. The body is used by the spirit because of its superiority. With these assumptions it does not seem difficult to explain why the human soul is immortal. It seems even simpler to explain why man is the image and likeness of God. If God is immaterial, man is the only one who would resemble God, since he is first and foremost a spiritual substance united to the body.

From an "apologetic" point of view Cartesian dualism may appear to be a success. In reality it is a step backwards in the understanding of nature by reason, with the negative consequences this has for the rational defence of faith: a disoriented reason is also weakened in its capacity to access higher truths, such as those pertaining to God. But this will become clear very soon after Descartes.

Science and soul

The successes of science and technology in the last two centuries may be due, to a large extent, to the fact that they have been able to observe nature with a view that could be called Cartesian: scientists have succeeded in finding, explaining and describing many of the mechanisms that govern the behaviour of nature. The benefits of this perspective are obvious. Moreover, the success of science has meant, especially from the mid-19th century to the present day, that scientific and technological rationality has become dominant. In this cultural context, the notion of the soul seems a relic of another age.

On the one hand, an understanding of the soul that is closer to the Cartesian than to the classical one has been consolidated. This means that when we speak of the soul we think of the spirit. It is not surprising, therefore, that John Paul II's references to the soul of animals, in an address in 1990, sounded scandalous to some and ridiculous to others. On the other hand, the scientistic self-limitation of reason, so lucidly highlighted by Benedict XVI in various writings, focuses its attention on the res extensa of the human soul.1focuses its attention on the Cartesian res extensa and leads to an understanding of nature based on mechanisms to be discovered and explained. The success that Descartes did not have with this still very naïve vision has been achieved by contemporary science. With a description of nature based on mechanisms and the laws by which they are explained, it seems unnecessary to resort to notions external to material nature. Science is sufficient to explain how natural realities are: there is no need for the soul. Moreover, it seems that it should be rejected if, as happens in many cases, the notion of the soul is identified with that of the spirit as an independent principle external to the material: dualism.

The soul of science

In summary, the soul is the specific and proper unity of each living being. This unity enables it to exercise operations that are also specific to the living. In the case of man, his spiritual soul is not only an expression of his organic unity, but of his transcendence.

The problem, therefore, is twofold: on the one hand, the living is identified with the mere manifestation of a complexity thought of at the level of the conjunction of mechanisms. On the other hand, it is problematic to identify the soul with the spirit. Both identifications lead to a deficient understanding of life, a useful but limited understanding. They also lead to the conclusion that spirit is unnecessary to explain reality, including human reality, which can always be reasoned about in exclusively scientific terms. This is a curious consequence, which Descartes probably would not have foreseen: to consider that the only difference between man and other animals is his complexity. Man is also a machine that may one day be imitated and perhaps replaced by machines, by androids.

Has the notion of the soul become obsolete? According to what has been said, the notion of soul does not appear when we explain reality from any particular science. If reality is considered to be known only from science, the notion of soul would be superfluous.

However, the knowledge of reality that led to the formulation of the notion of the soul moves in a methodical sphere that cannot be reduced exclusively to the experimental context offered by the various scientific methods. It is rather a knowledge with the aspiration to grasp reality in a global way, which is proper to the Philosophy. The descriptions we have given at the beginning of this question move rather in this sphere, in which the notion of soul, as it has been formulated here, is relevant.

This is not to say that Philosophy and the sciences are opposing knowledge, quite the contrary. Scientific activity, in discovering the extraordinary complexity and unity of living beings, has made it more and more evident that there is a clear difference between the living and the non-living. This peculiarity of the living is approached by the sciences through their own methods, which only confirm the existence of the reality that was expressed in the classical tradition with the notion of the soul.


  • Alma voice in: Mariano Artigas, Science and Religion. Conceptos fundamentales. Eunsa, Pamplona 2007.
  • Voice Alma in: Angel Luis González (ed.) Diccionario de Philosophy, Eunsa, Pamplona, 2010.


(1) Perhaps the most famous is the speech given in Regensburg on 12 September 2006, where he explicitly speaks of "the modern self-limitation of reason".