Plato’s Tripartite Soul
In the Republic (IV.436a–441c) the structure of the soul is explained to be a triadic unity, much like the Tetractys that is both one and many and creates through a process of three.
- Logos (Reason / Logistikon):
- Location: The head.
- Function: The rational and truth-seeking part of the soul. It governs through wisdom and logic, and when properly developed, aligns the whole soul.
- Thymos (Spirit / Thymoeides):
- Location: The chest.
- Function: The seat of courage, will, and righteous indignation. It acts as an intermediary between reason and desire, and when harmonized with reason, it supports moral action.
- Epithymia (Appetite / Epithymetikon):
- Location: The abdomen or lower body.
- Function: The source of bodily cravings and instinctual drives—hunger, thirst, sensuality, and material accumulation. It must be tempered by reason to maintain order in the soul.
This triadic structure functions within everything and not just an individual, according to Plato. In the Republic, he explains how groups of people collectively establish a soul that operates in this pattern and that the ideal society would be founded and structured along this threefold pattern.
Neoplatonic and Hermetic Layers of the Soul
Just like the Tetractys shows, what appears to be a simplistic work of one and three encompasses something vast. Later traditions like Hermeticism and Neoplatonism expanded this foundation to illustrate the soul’s journey through the cosmos and its experiences in the world of matter. These developments explained more layers:
- Nous (Divine Intellect):
Not merely a part of the human soul, Nous in Plotinus’ system is the divine Intellect that is in eternal contemplation with the Forms. Within the human being, the spark of Nous represents the highest potential of consciousness: the direct, unmediated apprehension of divine truth. It is the “I Am” that can be narrowly focused or universally expansive. Parmenides, around 500 BC, said “To be aware, and to be, are the same.”
- Psyche (Soul):
The soul is now seen as immortal and capable of descending into material incarnation or returning to divine unity. It “wears” personalities and identities like garments in each life.
- Ochema-Pneuma (Soul Vehicle):
Emphasized in Neoplatonist and Hermetic texts (notably Iamblichus and Proclus), this is a subtle, astral body that accompanies the soul through incarnations. It acts as a bridge between spirit and flesh, imprinting astral influences and serving as the medium through which divine impressions or symbols (synthēmata) are received. - Pneuma:
Prominent throughout ancient metaphysics,pneuma is the animating breath or spirit that fills the cosmos and animates organic life. In the theurgical context, it is linked with the vital breath that sustains the ochema and receives divine influence. In Latin it was anima, in Hebrew and Arabic ruach, and in Sanskrit prana. It has its physical counterpart in the wind.
These concepts are necessary to illustrate the multitudes of combinations that the triadic structure creates. Divine Fire, which is the creative principle in all things from the purest spirit to the world of matter, has the Form of a triangle. Plato illustrated this divine Fire as the tetrahedron or the three-sided pyramid. Everything emanates from Fire, from the first flicker of primordial light that sparked the cosmos to the world of matter that depends on the Sun for its existence.
In the Timaeus, Plato describes the cosmos in similar terms to the Hermetic doctrines, with the Demiurge or divine craftsman forming the human soul using the same patterns that were used to design the cosmos itself. The Demiurge of the philosophers was different than the Demiurge as described by the Gnostics, who considered it an ignorant and evil being whose sole purpose was to imprison souls.
This idea was vehemently opposed by Plotinus, who maintained Plato’s doctrine that the Demiurge was an extension and function of the divine. The pain and evils experienced in the material world was an unavoidable part of existence for Plotinus, a “necessary evil” so to speak because the very nature of matter was decay. The Demiurge did the best he could with the materials he had.
Psychological and Cross-Cultural Parallels
Plato describes the Demiurge as crafting the archetypal human soul in the proportions he fashioned the cosmos: a trinity. Like the Tetractys, it can contain and create a vast array of other patterns, but all is ultimately reducible to a three-fold structure. The fundamental building blocks of reality, according to Plato, is a triangular pattern. When it takes on three dimensions it becomes the tetrahedron. The human soul within the body is designed like the cosmos consisting of the upper, lower and middle worlds.
“The divine part of the soul is located in the head… The mortal part, full of passions and desires, lies in the belly. Between them is placed the spirited part, which mediates.” Timaeus 70a–b, trans. Donald J. Zeyl
Similar in some ways to the seven chakras of Hinduism, the human soul’s focal points in the body are the head, chest, and abdomen. The head contains a spark of Nous and the lower belly is the source of our material urges, such as hunger, sex, uncontrolled emotions, and so on. In the heart is a mediating force between the two, the source of emotion tempered with reason. The sense of self is made of a combination of these three.
Aristotle followed the tripartite model in his treatise On the Soul, classifying the souls of all living things as vegetable, animal, and rational. Whereas Plato focused only on human souls, Aristotle sought to explain all of nature. According to Aristotle, humans are composed of all three types of souls found in nature but are the only ones to possess a rational soul. Aristotle’s writings were dominant in western psychology until the late 1800s. In modern psychology terms, this triadic division is comparable to the Id, Ego and Superego.
The Id is the lower portion focused entirely on the physical, the Ego is the mediating influence and the Superego is the source of reason. Similarly, the description of the mind as dominated by the left and right brain hemispheres has parallels. Left brain thought is the hyper-analytical mode that apprehends the physical world and body while right brain thought is the thymos or imagination that mediates and perceives holistically.
The brain functions at its peak when both hemispheres are perfectly synchronized, which allows the Logos or the higher mind to communicate clearly.
Henosis and the Awakening of the Eye of the Soul
In the Republic, Plato elaborates further on how the soul operates. The ideal human society would be structured in a similar pattern to the human soul. A city is a living being and has a soul, composed of its inhabitants, and collectively functions in a similar manner to an individual. This view is a very ancient one and is the reason for tribal societies and ancient cities having a personal guardian deity, such as Athena’s role as the founder and protector of Athens which bears her name.
Through a life devoted to philosophy, the Eye of the Soul can be awakened through henosis and the soul develops in stages. This is the purpose of theurgy according to Iamblichus. At first glance, it could be assumed that henosis is a singular experience and once it is achieved, the goal has been reached. This was not the case, as we will see shortly. This experience was an entry point for developing the soul even further.
In the Allegory of the Cave, this could be likened to the first glimpse of sunlight at the entrance. It is overwhelming and results in temporary blindness, and the prisoner becomes determined to escape. This presents a new problem in that the prisoner’s eyes are accustomed only to darkness and must gradually build their ability to see.
It begins with examining the shadows on the wall (representing the world of matter), then studying the reflections of the stars in puddles (the astral spheres), followed by taking small glimpses of the sunlight until the ability to see outside has been achieved (the World of Forms). Complete freedom is attained when the prisoner finally leaves the cave to live outside, representing the final stage of development.
The eyes of the prisoner are an allegory for the Eye of the Soul. When all three faculties work together in a harmonious way, the Eye can look without obstruction and Nous is free to operate. When the human spirit is examined through the Tetractys, the physical body itself is the bottom row of four points, perceiving the four elements that compose the world of matter.
The epithylmia is the row of three points above it, corresponding to the astral spheres. The thymos, or mediating spirit, is the row of two points and is caught amid the struggle between opposites. The Logos or reasoning spirit is the singular point on top, the Monad.
Nous is the entirety of the Tetractys, encompassing all ten points functioning in unison. It can see the intricate connections between the singular point of the Monad on top and the multiple copies of itself below to the lowest level. Number sequences like Pascal’s Triangle not only convey universal mathematical laws but serve as meditative devices for understanding this function of the soul.
When the Eye of the Soul is fully opened it experiences the entirety, as one thing, without restricting its awareness to any one point. The self becomes both the observer and the observed as Nous. The perception, understanding and experience of one and many is henosis or divine union that can only be known by direct experience.
Left: Tetractys in is basic form. Middle: Renaissance painting of God’s eye. Right: Pascal’s Triangle.
Analytical Frameworks: The Divided Line and The Tetractys
“Reasoning (dianoia) moves step by step from premise to conclusion, while noûs sees all at once.” – Enneads V.1.6
This is further illustrated by the Analogy of the Divided Line in Republic, Book VI (509d–511e). While the dialog does not specifically quote Pythagoras, his influence is plainly visible. Socrates likens the soul to a single line, divided into four unequal segments. Each section represents part of the psyche and how it experiences its surroundings.
Keep in mind that the created world has a soul of its own, collectively composed of all things, and its structure mirrors that of humans. The more that the human soul awakens the more it perceives its correspondence, inner and outer.
The Visible Realm (Lower Segment)
- Images (eikasia): Shadows, reflections, and illusions. These represent the most illusory form of perception, the least real, and best described as our ordinary waking mind going about mundane tasks and our bodily senses.
- Belief (pistis): This corresponds to physical objects themselves, which we perceive through the senses. Though more real than images, they are still not true reality, since they are changeable and imperfect copies of higher Forms. The mind’s corresponding function is imagination and contemplation of what it perceives through the senses. At its highest level it corresponds to exploration of parts of the astral spheres.
The Intelligible Realm (Upper Segment)
- Thought (dianoia): Mathematical reasoning which operates through abstract thought but still relies on assumptions. This approaches the World of Forms and is the foundation of Pythagorean theology. Geometric Forms beheld in states of ascension are, in a sense, pure images of the Forms.
- Understanding (noesis): Direct intellectual insight into the Forms, especially the Form of the Good. In terms of religious experience this is union with the divine. This is the highest kind of knowledge—pure, unmediated understanding of eternal truth.
The line in Pythagorean thought is the most primal shape that can exist, next to a circle or point. It provides the potential for dimension. A line connects two points and if the creation of the cosmos is imagined geometrically, its beginning is total emptiness. The creative principle constricts itself into a single point, the Monad. Its first act to enable creation is to duplicate itself into another point. Because three-dimensional space does not exist yet and it is operating on a two dimensional plane, the Monad can only connect to the replicated point with a line because it is the most direct and harmonious way to do so.
The line becomes the embodiment of the Dyad, or duality and opposition inherent in the number two. The human soul, when it is not in harmony with its source, is in a state of opposition yet is still a direct emanation of it just as a line is a direct extension of a point. The divided line analogy also fits perfectly as a representation of the Tetractys when examined deeper.
For the sake of simplicity, let’s label each division of the line as A, B, C and D. Each is a portion of the human soul according to Plato’s tripartite model. D is the physical body itself, C is the appetitive soul, B is the spirit, and A is Logos or Reason. Each portion interacts with other portions. When there is disharmony in the soul, each is vying for supremacy because the lower two portions, C and D, the body and the appetitive soul, wants a sense of dominance. Despite this struggle, these four parts cannot exist by themselves and must interact with each other to for the body to be alive. No single section can interact with itself because it is part of a greater whole. When we examine all the possible combinations of interactions, it is the Tetractys.
When one portion interacts only one other portion, AB, AC, AD, BC, BD, and CD make six. Interactions of three portions, ABC, ABD, ACD, and BCD, make four. In total, this makes ten, the number of points in the Tetractys. All four interacting together, ABCD, makes one, the number of the Monad, and represents the soul having gained noesis and the Form of the Good.
Within this simple analogy explained by Socrates, we see an example of his unique ability to speak from flashes of intuition that reveal profound ideas when examined further which was the way he practiced philosophy.
Shortly afterwards in Plato’s Republic, Socrates is asked to define the Form of the Good. He claims he is incapable of this but introduces the Analogy of the Sun, calling the celestial body a “child of the Good” and its visible representation. Just as the Sun provides light for physical life and grants the ability to both see and be seen, the Form of the Good provides truth and being to the intelligible realm.
When the Form of the Good is perceived, the Eye of the Soul is fully opened, achieving noesis, and the soul is filled with divine light and clarity. This climactic realization of henosis completes the soul’s journey through the Divided Line.
We continue this exploration of the soul’s highest functions in The Eye of the Soul Part 2: Inner Astronomy and the Chariot of the Soul, examining the soul’s structure and cosmic journey through later Neoplatonic models.