He assumes that morality and justice will only be found when three other characteristics are also exhibited. Plato uses his argument by elimination to find morality within ones self. The struggle to be good and truthful is something many people face. Platos insights into our personal motivations when deciding how we should act are as true today as they were when he first published them.
Plato believes we commonly feel numerous impulses pulling us apart in various directions at once, and he attempts to explain how the human soul functions as it is bombarded with sensory perceptions as well as intellectual ideals. He begins talking about the love of knowledge within his own society, which happens to be the base of his argument for morality. (143) Without knowledge, one cannot find truth or justice morality. When looking deeper into the motivations for our wants and desires, Plato poses the question, is there just one single thing which we use for doing everything, or are there three and we use different things for different tasks? (145) He also considers how we decide which tasks to get going on. Plato confirms his idea that humans have more than one of these aspects by stating, the same one thing cannot simultaneously either act or be acted on in opposite ways in the same respect and in the same context.
(145) If this is found to be happening in the case of these aspects of ourselves, there will definitely be more than one. In this way Plato develops his idea of the mind being broken down into three separate parts; the passionate, the rational, and the desirous or mercenary. As previously presented, the first part does, the next thinks, and the final part of our mind desires. The presentation of this idea that it takes these three separate parts to function accordingly helps Plato present the possibility of people doing these at the same time; or for example, there may be one part of the mind functioning while another does. Plato will not accept this definition of the situation.
He uses examples of a person standing still in one place, but moving their hands and head, or a top spinning in one place to describe his thoughts. He will not say someone or something is moving and still at the same time. (146) This is because of the semantics; one may become confused because the moving and still adjectives may be used to describe the whole object in motion over a plane, or parts of the object in motion while being still over that same plane. Plato argues that acceptance and pursuit of something are not related to rejection and distaste for that same thing.
(146) Having an appetite for, or desiring that thing is acceptance and pursuit of it. (146-147) Similarly, denial and avoidance of that thing is rejection and distaste of it. (146) Plato presents an example on pages 149 and 150: sometimes humans have an appetite to drink while also refusing to drink. Because acceptance and rejection are opposites, they cannot belong to the same part of the soul. (150) The rational part will do the planning, symbolizing wisdom, while the passionate part will obey the ruling part and employ its courage to carry out the plans.
Plato then goes on to present his belief that self-discipline is the device that keeps each of the parts of the soul in check, because it only comes about when they are in agreement. Without self-discipline, according to Plato, chaos and thievery would abound. Everyday people have to overcome obstacles and make choices for themselves. In the first half of his book, Plato offers his view that addresses what humans do when faced with choices. (135) In Platos presentation of the story of Leontius, the son of Aglian, he strengthens this argument. As the story goes, one day Leontius walked by an