Like many people today, Plato held the belief that the human being was both dualistic in nature, namely comprising of two separate entities; body and soul, and possessing a soul that would survive its embodied state. Plato saw the soul as immortal through being cyclical in nature and having this cycle comprising of three states: prenatal, embodiment, and post–mortem. Plato formulates three arguments to back up his claim that the soul is immortal: the theory of opposites, the theory of recollection, and the theory of destruction. Plato touches on the theory of a soul's immortality in many texts but the one text that deals principally with this issue is "Phaedo." Although Plato's arguments are very cohesive and well constructed and in the day they were written must have seemed infallible; when we look back at them today there are a few flaws that leave Plato's theories and arguments somewhat unsubstantiated. In order to better understand Plato's argument as a whole, this essay shall approach each theory and its problems separately before concluding them all as a whole.
             The theory of opposites is the first theory that Plato offers to his compatriots in Phaedo for proof of immortality. This theory is based on the notion that "the souls of the dead must continue in existence; for from what other source could those souls come which animate the living" . This statement is backed up by a couple of examples; things become bigger from having been smaller, weaker from stronger, faster from slower, worse from better . Thus if these opposites are so prevalent in life why not life itself, as if from sleep to being awake then Plato supposes the same must apply to life from death. If we come from death to be alive then it must be true that our souls pre – existed this life and are thus immortal and cyclical in nature, "Failing this cyclic process everything would end up dead" The problem for this line of argument is simple, it assumes...