The differences of Aristotle’s theory of the Soul and Plato’s theory of the Soul are quite large. Aristotle was a student of Plato, despite this, their theories about the soul were significantly different. Another result of Aristotle being a student of Plato meant that he spent much of his time comparing his own theory of the soul with that of Plato.
The reasons for the differences between Plato and Aristotle’s theories can be seen from their world ideologies. Plato was a dualist and a rationalist. Essentially he believed that the physical world that we inhabit, and the “spiritual” world are two separate things (hence the dualism), and that the only true knowledge was using reason (hence the rationalist).
Aristotle on the other hand believed that rather than reality being a “shadowy” copy of the World of Forms, where the original copy of everything could be found, Aristotle saw that this world was the only available thing that we can base knowledge on. The only thing that we can be sure of. For Aristotle, perception and sense experience (experience being the stuff that we gather from the five senses, a perception of reality) has to be the foundation for true knowledge, scientific and philosophical. This shows Aristotle to be a monist and an empiricist.
The first and perhaps the most obvious difference between the two theories of Plato and Aristotle is the distinct difference in the longevity of the soul. Plato’s “Soul” was immortal, imperishable, and eternal. The Soul was also something that had no lasting connection with the body. The body was something that died and decayed, a prison for the soul.
This theory of the Soul was justified by Plato through the theory of forms. For Plato, who, in his theory of the forms. Plato, who outlined in his “theory of the forms” that we all had the concept of a “perfect circle” or “a perfect triangle” not because we had seen either of these before but due to the fact that the image was already known to us through the world of the forms.
This theory also explained how the soul was generated, the soul already lived a life in the world of forms, a world that cannot be destroyed as the body can be destroyed. Once you die, the soul is free for a short time before being entrapped once again in another body (for reasons undisclosed to us).
In this respect Aristotle disagreed with Plato. He believed that a soul existed, as did the body, but rather than thinking of the two as almost totally separate entities. He thought that the soul was part of the body, and it was made with the body.
For Aristotle the Soul was the body fulfilling a purpose, a function, from the smallest amoeba to the most intelligent human, everyone has a soul, their fulfillment of purpose. He believed that once the body died, the function lost, so was the soul lost. When the body dies, the soul has nothing to support it. Aristotle’s analogy of the oarsman is apt at explaining this. If a boat is the body and the oarsman is the soul, neither will function without each other. If the boat had no oarsman, it would drift and eventually capsize. If the oarsman had no boat, he would struggle in the water, and eventually drown. The Soul and the body are inseparable, just as sight is inseparable by a functioning eye.
Both the Aristotelian Soul and Body need each other, they have formed a symbiotic relationship, to a degree, both needing each other for the other’s interests. The soul and the body are you.
According to Aristotle when we are born we have the capacity to learn and to reason. The knowledge that we gather throughout our lives defines us, our experience in the world defines our person. These sets of experiences becomes our soul and our “character” to a degree. Aristotle’s soul is changeable, and changes as our character does, and our experiences change. When our function as a human ends, being able to reason, with death, so does our soul die. This is as a soul cannot exist without a body, just as a body cannot survive without a soul, much like the allegory of the oarsman.
Aristotle’s soul is considered to be many things, such as movement and sound. The soul is also effected by where it is, and whom it inhabits. Less complex souls are given to less complex life. Plato and Aristotle both divide their soul into different sections, for Plato it was split into three, the Logos , the Thymos , and the Eros . He defines this in book IV of the Republic. Aristotle splits his version of the soul into four, the Calculative, the Vegetative and the Desiderative. These are rather more self explanatory.
Although earlier, I stated that whilst Plato believed in an immortal soul, Aristotle did not, Plato does believe that a part of our being survives after our death. Although it is not the soul itself, as Plato tells us it is. Rather than this surviving, Aristotle believed that the “reason” of the thing, survives, the specific qualities that it has. Plato taught Aristotle, we may have thought that this would have influenced the student, there is certainly a distinct similarity between the two.
As Plato believed that things that we see in the Physical world are merely shadows of the true meta-physical world (the theory of the forms). Likewise, to Plato, our bodies are “of” this world, being physical, and therefore the only “real” meta-physical soul is true.
Plato illustrated his idea of the soul, much like Aristotle did after him with the oarsman allegory. Plato’s demonstration and metaphor for his soul is the analogy of the charioteer. The mind, being the charioteer, is directing a chariot, one being well bred, and easy to lead (the soul), the other short and troublesome (the body). The Mind’s job, the intellect of the trio, is to strike a balance to make it all work.
Plato’s Soul is also unchanged by events, unlike Aristotle’s, despite it being made unclear in the Republic, where Plato actually states the contrary (perhaps due to our lack of linguistic capability for such issues, for the Greeks, the “Soul” meant many things not just an individuals essence. For Plato, the soul is unchanging, and virtuous.
Aristotle’s soul is also “good” in a sense, much like Aristotle’s “virtue ethics” . This means that a person is judged to be moral or immoral based on their innate good or bad, rather than the perceived moral value of their acts. In this way, virtue ethics focuses more on how a person can become good, rather than how they can perform good acts. This is the same with the Soul, something that is changeable and can be affected by the outside world.
Plato, the dualist of the philosophical duo, believed that a harmony must be struck betwixt the soul and body. Aristotle also believes that the different parts of the soul have to act in harmony, the selfish ones, vegetative and desiderative (the parts responsible for looking after our needs) must be kept in check.
Christians would tend to argue for the Platonic Soul, that soul being the immortal one. I would disagree, as the idea of a “soul” which doesn’t change, and is merely an idea, doesn’t seem realistic to me. There is not evidence for the “world of forms” despite being a fascinating theory. Aristotle’s empirical ideas seem far more coherent to me than Plato’s. For this reason, Aristotle’s soul seems more convincing, it seems to me that empirically the ideas seem correct, whereas Plato’s, whilst being philosophically sound, are more far fetched.
Generally, in finding a better theory, I tend to turn to Occam’s Razor, “All other things being equal, the simplest solution is the best”. I find that Aristotle’s explanation offers a far more plausible and simple explanation to existence than Plato does, who creates an entire new metaphysical world.
