Plato’s definition of the soul can be looked through two parts; Phaedo's and the Republic’s theory of the soul. In the Phaedo, the soul is composed of two parts. First, it is noticeable and second that we can not see our emotions and senses. Plato mentions Socrates and he is aware that the body and soul are different. He compares the soul to a ‘perceptible and perishable being’. The soul suffers less obstruction than the body. The soul is responsible for the life of any living thing. The soul can be directly responsible for certain actives. Plato defines the soul from the Phaedo as having an emotional and intelligent state. The soul has life, going from one body to another. The soul is connected to the mind but is not responsible for all of our body’s cognitive actives.
In the Republic, the soul is living. It can have a just or a happy life and an unjust or bad or evil life. The soul being alive is a functioning role. The soul can be both good and bad. Depending on how just or unjust a person lives their lives. It depends on their condition of the soul if certain characteristics exist such as virtue or wisdom. The human soul has three parts; reason, spirit, and appetite. That our desire and averse work against one another. The soul does one thing and then simply does a counteraction against its first action.
Aristotle defines the nature of the soul or De Anima into different areas; perception, memory, sleep, and dreams. Aristotle defines the soul and its connection as an evolving, living cell. It is not just a human element, but it also connects with plants and animals. Aristotle sees the soul as organic, a life-like creature. He structures the soul as a system of hierarchy. With each part fulfilling a specific role. Plants are vegetation, animals have power and perception and humans have a rational soul through reason and thought. He distinctions that the souls and bodies are different. That each part of the soul can be seen with different traits and functions. Such as hearing and seeing. These functions of the soul use the ‘central sense’. That is, an object can be recognizable through more than one sense. A person may not be able to see a flower, although could recognize it with either small or touch. With this sense, there is also an effective faculty. Aristotle describes this part of the soul as irrational and can be controlled with reason and believes it to be the highest level.
In De Anima II chapter 1, Aristotle makes multiple definitions or a nominal definition. The soul is a physical part of the body, being described with organs. Although Bolton argues that an organ needs to be alive. This could correlate that Aristotle may have not understood biology (p. 260). Bolton further explains that these different definitions contradict one another.
My argument would lean towards Plato's definition of the soul. Aristotle seems to define the soul as more of a physical, living thing. Plato clearly defines the soul as separate from the body. His definition almost seems to be the advice for a person to live well. And this is evident in the Republic. Plato states that the soul will fight against our desires because we know that candy is not a healthy choice when it comes to hunger. Our soul may convince us to wait for a little. If we did not have Plato’s definition of the soul, we probably would not have our second thoughts or doubts about our choices and decisions.
Bolton, Robert, ‘Aristotle's Definitions of the Soul: ‘De Anima’ Ii, 1-3’, Phronesis, vol. 23, no. 3, pp. 258–278 < JSTOR, www.jstor.org/stable/4182048> [accessed 1 January 2020].
Lorenz, Hendrik, ‘Ancient Theories of Soul’, in The Stanford Encyclopedia of Philosophy <https://plato.stanford.edu/archives/sum2009/entries/ancient-soul/> [accessed 2 January 2020].
Plato, Republic, 2nd edn (London: Penguin Classics, 2007).