According to Socrates
In the first part of the Phaedo, Socrates lays out his theory regarding the immortality of the soul. Near the end of this part he breaks down the body and soul and shows us that they are very different in permanence and structure. The body and soul, which are are interlinked when alive and separated at death, are fundamentally different constructs. The dichotomy here is expressed through the argument as opposites of composition, ideal forms, solidity, spirituality, and visibility.
Socrates opens the overall discussion at 64c by defining death as separation of the soul from the body while the argument regarding the duality of body and soul is picked up again at the end of 78b with the major premise being whether or not the soul is something that can be scattered. Socrates continues by stating that anything that is non-composite will likely stay in one piece over time, while composite or compound items will eventually break down into individual parts. Furthermore, composite objects are subject to change and “vary from one time to another” (78c) with things that are static likely being non-composite in nature.
Socrates now elects to pull in the invisible perfect forms that are the ideals of the corporeal existence. “The Equal itself, the Beautiful itself, each thing in itself, the real … remain the same and never in any way tolerate any change whatever.” (78d) This is a continuation of a previous line of reasoning that starts at 65d with the introduction of the pure concepts that are partially enumerated as the Beautiful, the Just, and the Good and culminating with the realization that perfect knowledge of these can only be obtained with a total disconnect of the soul from the body. The perfect forms presented are actually assumptions that serve to further the argument along.
Our direct existence allows us to experience the particulars of the beautiful such as “men, horses, clothes, or other
References: Morito, Bruce (2000). Introduction to Philosophy West and East, Study Guide. Athabasca: Athabasca University. Grube, G.M.A. (1977). Plato Phaedo (translation). Indianapolis, Indiana: Hacket Publishing Company, Inc.