Explaining the relationship between the body and soul is a very important philosophical issue that is still considered one of the hardest subjects to clarify. Two things are totally accepted amongst scholars:

1- Two very different types of characteristics are evident in man; one being spiritual/mental characteristics such as: Awareness, knowledge, willpower, identity, happiness, sorrow, pain, etc., and the other being material/physical ones.

2- Despite their great indifference, these two types of characteristics are inextricably and deeply intertwined and interrelated.

As for how this relationship between the two can be philosophically justified and explained, there is a difference of opinion amongst philosophers.

One researcher writes: “The issue of the body and soul has been one of the main topics addressed in philosophy ever since ancient times, although new discourse of it began during Descarte’s time. Some philosophers believe that different matters such as awareness, identity, the continuation and life of an individual after death, mental illnesses, free will, the variance of man's desires with those of other creatures, etc., are all based on what we say regarding the issue of the relationship between the body and soul. The key question of how the two types of characteristics man bears are deeply intertwined is what gives rise to questions regarding all of these matters. For instance, when a needle goes in our finger, we feel pain; the question is how a physical change in our body grants us such a feeling and experience of pain? Take knowledge for example; when we become aware of something, what takes place in our body? Are the atoms, cells, molecules and tissues in the brain and body the only things responsible for this knowledge? Presenting an acceptable and considerable explanation by philosophers is very taxing and something we are yet to see despite all their efforts to do so till now. The gap between these two types of characteristics is so great that although there has been great development in philosophy over the years this question still remains unanswered.[1] What process takes place in the nervous system is something that neurologists have to address, but whether mental and spiritual things that take place for the body are something only nerve-related is something philosophy has to answer.[2]

Anyhow, to clarify this matter, we are in need of firstly getting to know what philosophers’ views are regarding this subject:

The views of philosophers regarding the relationship between the body and soul

If one concentrates on the sayings of philosophers regarding the soul and body, their viewpoints can be divided into the two categories of a “monistic” approach and “dualistic” approach, because some completely deny any traces of a soul along with the body. On the other hand, there are philosophers that believe in both the soul and body. Having said all the above, it can be said that the best explanation of this profound relationship is the one presented by Mulla Sadra in accordance with his “Transcendent Philosophy” which can be called a ‘dualistic monistic’ approach so to speak. Anyhow, since the roots of past philosophers can be found in the viewpoints of contemporary ones, we will address this question via a modern perspective, and in order to keep it short, we will only list two of the most famous votes on it:

“The dualistic approach”

Ever since a very long time ago till today, many philosophers have looked at man from a dualistic perspective. They would see man as a being living in a material world ruled by physical laws and composed of materialistic particles and ‘building blocks’, but at the same time bearing an essence in total contrast with these things. This essence was named the ‘soul’ or ‘spirit’. For instance, Plato would maintain that all of us bear a simple (not compound), divine and unchangeable spirit, and at the same time, a compound body that is prone to spoiling and ruin; meaning that the body is only a means of presence in this material world; a short-lived stage of the soul’s eternal journey. To put it more precisely, Plato wasn’t saying that we are beings that possess a soul, he was rather saying that we are one with the soul, meaning that all we are is the soul. It is the soul that defines the essence of man.[3]

Anyway, in contemporary philosophy, Descartes is a dualist in this matter. Based on his personal method, he says: “…because I have on one hand a clear and distinct idea of myself, insofar as I am only thinking, not an extended thing, and on the other hand a distinct idea of body insofar as I is only an extended thing, not thinking, it is certain that I am really distinct from my body, and can exist without it.”[4]

According to him, the essence of material substance is ‘extension’, meaning the ‘filling up of space’, while the essence of immaterial beings is ‘thought’ or ‘awareness’. What he means by thought is a complete series of actions and stages the body goes through such as seeing, feeling, comprehending, judging and doubting along with thinking (in its specific sense). The difference between the characteristics of these two entities in no way stops them from affecting each other.[5]

An analysis and critical look at the dualistic approach

Two important questions remain with this approach:

1- Just as the dualism between soul and body is axiomatic, the unity and oneness of man is also axiomatic. The dualistic approach in no way removes the clear contradiction between the two and doesn’t present any explanation that can solve this problem.

2- The body is materialistic, while the soul is immaterial; this theory has no solution as to how these two are interrelated and interactive.

“Transcendent Philosophy’s” theory: The body; a low degree of the spirit

According to Sadraism or “Transcendent Philosophy”, the body and spirit are one and two at the same time, making this theory a dualistic one, but not Descartes’s dualism that says the body and spirit are two totally distinct entities. Rather, the soul and body are both distinct but at the same time are one (and this isn't self-contradictory, given its explanation), because according to Sadraism, because of its existential strength and comprehensiveness, the soul bears a unity and oneness that is in no way in contradiction with plurality. It is an essence that has multiplicity while being one, and has unity while being multiple at the same time. On this basis, there is a very deep relationship between the soul and body (which is that the soul has different degrees in which the body is one of them).

Ayatullah Hasanzadeh Amoli says in explanation of this theory: “The body is a low degree of the spirit, and the spirit is the whole of the body, and the body is the manifestation and crystallization of the soul and its merits and potentials in this world.”[6]

Sadraism has been able to solve all of the problems Western philosophy faces regarding this subject. The first question (how the body and soul are two and one at the same time) is solved by saying that what is meant by the unity of man is ‘true and shadowy unity’ (Al-Wahdatul Haqqul-Dhilliyyah) which isn't the opposite of multiplicity, and since true and shadowy unity is absolute (not that absoluteness is its condition, rather, it is unconditional, giving it maqsami absoluteness instead of qismi absoluteness) and doesn’t have an independent existence and can only be found in its subcategories that are the maqsami absolute plus a condition, and when this absolute becomes conditional, it doesn’t become something other than the maqsami absolute, differing with it in instance. In this context, all multiplicities are a manifestation of that one essence, not that they have an essence other than its essence. Thus, it can be said that on this basis, the body and spirit are one despite their dualism.

Also, Sadraism has solved the second question through ‘transubstantial motion’ (harakah jawhariyyah) and the ‘corporeal createdness’ (Jismaniyyatul-huduth) of the spirit and looking at ‘cause and effect’ as manifestation and traits (sha’n), enabling Sadraism to explain the relationship between the body and spirit in the best way.

The ways of proving the theory of the unity of the body and soul

The first reason (Intuition)

By taking into consideration several self-evident and clear matters, it can be concluded that the body is one of the degrees of the spirit:

a) Every person intuitively knows that he/she bears two types of characteristics; some are spiritual while others are material.

b) Every person clearly and intuitively knows that he/she has an identity in which all actions and existential traits are attributed to. For instance, something one has done many years back is still attributed to him although as all know, that body is no longer the same one and has changed over the years time and time again. Thus, the combination of the body and soul is ‘composition through unification’ (tarkib ittihadi) and not ‘composition through annexation’ (tarkib indhimami); man is an extended entity that stretches from a high degree (thought) to a low degree (body), and all of these degrees make up one personality and person.[7]

c) The only rational explanation for two things that are one by virtue of ‘composition through annexation’, is to say that one is the manifestation of the other, leaving us with no choice to do same with the relationship between the body and soul, and since the soul bears greater existential strength and primacy in comparison with the body, the body is its manifestation, not vice versa. As was said, Sadraism has solved one of the West’s greatest philosophical problems via this method.

The second reason (Experience or the effects of the body and soul on one another)

This argument is based on two premises; 1- The body and soul affect each other. 2- Things that are such, are one. It seems that the first is very clear to those who are familiar with psychology; even those who deny the soul completely, still believe that mental and physical modes of the body have an impact on each other.

As for the latter premise, according to Sadraism, things that are such are one, because things that are totally distinct and diverse cannot have such a relationship. In other words, according to Sadraism, what ‘cause and effect’ actually is, is manifestation and that is why a ‘cause and effect’ relationship is clarified as a unifying relationship.

In order to further explain how the impact the spirit has on the body is a reason for why the body is a low degree of the spirit, we will give an example: If we weigh someone at a certain age we can say he/she can lift a so and so load at this age and weight. At the same time, the same person can lift a load heavier than that in the state of anger or love. The question that comes up here is that this person is the same one before having anger or love, with the same weight and age, so what makes the difference? Why is he able to lift something heavier when angry or in love? It isn't because of his body, because that hasn’t changed at all, and if the spirit is to be material, then two material entities next to each other also haven’t changed in weight. This lets us know that what has changed has to do with what is called the intellective soul in which the body is a low degree of. Therefore, lightness, heaviness, taking command and jumping, freshness, beauty, and all of things body does such as the brain and its endeavors, the digestive system, the heart, etc., all stem from the intellectual soul that manifests both on the inside and outside of the body and has a specific name that corresponds with every place and circumstance.[8]

Conclusion: According to the theory that says the body is the low degree of the spirit, one must say that the body is in the soul, not that the soul is trapped in the body[9], because the soul and spirit bears a comprehensiveness and existential strength that makes the body one of its ‘rays’ and manifestation.