However, Plato’s theory states that the soul existed before it inhabited the body in the world of Forms. At conception the soul descends from the world of Forms and inhabits the body. However, once the body eventually dies the soul ascends back into the world of Forms where it joins with the Form of the Good. Because of this ‘cycle’ Plato believed that the soul was immortal.
The Platonic soul comprises three parts:
- The Logos
- The Thymos
- The Pathos
Each of these had a function in a balanced and peaceful soul.
The logos equates to the mind. It allows for to prevail, the thymos comprises our emotional motive that which drives us to acts of bravery and glory, the pathos equates to the appetite that drives humankind to seek out its basic bodily needs.
Aristotle believed that there were four sections of the soul.
- Calculative
- Scientific
- Desiderative
- Vegetative
The Calculative part and the scientific part are on the rational side used for making decisions. The desiderative part and the vegetative part are on the irrational side responsible for identifying our needs.
Plato sees the body as a “prison” for the soul. For Plato, the life of the soul in the body is contrary to its nature. So Plato is a dualist with respect to this question. Body and soul are radically different kinds of things, capable of existing separately, and it's assumed that the soul is superior to the body.
For Aristotle, body and soul are different kinds of things, because one, the body, is matter, and the other, the soul, is form. But this is not to say the body is a prison, or that the soul is “better” than the body. Everything in the universe is composed of matter and form, so it's not surprising that persons are too.
Plato did not believe that the mind contain a separate world made up of experiences of the real world. There is no separation between the object and the experiences of that object. This different to the more modern idea that we exist in a world contained in our minds, made up of internal impressions of external experiences.
According to Plato the soul is unchangeable. It is the form of the human being. It is what defines the loose collection of chemicals as a human being and not loose collection of chemicals. An important part of the Form of the human beings is our ability to reason and to apprehend universals. Universals are the general, abstract qualities such as goodness that individual objects participate in. Through the knowledge of the universals humans can come into contact with the external. In this way, we can come to understand concepts such as justice and goodness through our experiences of things that re just and good.
The existence of the soul had an important implication for Plato’s beliefs in the afterlife, and of the rewards for the virtuous life. Plato appears to have believed that the soul will be reborn in a new body, and that those who live virtuous lives will somehow be rewarded.
Soul is defined by Aristotle as the perfect expression or realization of a natural body. From this definition it follows that there is a close connection between psychological states, and physiological processes. Body and soul are unified in the same way that wax and an impression stamped on it are unified. Metaphysicians before Aristotle discussed the soul abstractly without any regard to the bodily environment; this, Aristotle believes, was a mistake. At the same time, Aristotle regards the soul or mind not as the product of the physiological conditions of the body, but as the truth of the body the substance in which only the bodily conditions gain their real meaning.
The soul manifests its activity in certain "faculties" or "parts" which correspond with the stages of biological development, and are the faculties of nutrition (peculiar to plants), that of movement (peculiar to animals), and that of reason (peculiar to humans). These faculties resemble mathematical figures in which the higher includes the lower, and must be understood not as like actual physical parts, but like such aspects as convex and concave which we distinguish in the same line. The mind remains throughout a unity: and it is absurd to speak of it, as Plato did, as desiring with one part and feeling anger with another. Sense perception is a faculty of receiving the forms of outward objects independently of the matter of which they are composed, just as the wax takes on the figure of the seal without the gold or other metal of which the seal is composed.
Aristotle and Plato’s theories are like two polls apart, and they are different ways of looking at the same thing. Whereas Aristotle favours the more scientific observational techniques for reasoning in his theory, Plato does the complete opposite by rejecting what is conventionally perceived to be right. Plato even states that the only way to have true knowledge of God was through the soul and uses figurative language, the ‘eyes’ of the soul with which to ‘see’ God. Whereas Aristotle took the more clinical approach, that your soul is not a separate entity, which therefore cannot ‘see’ God.
