Plato (c. 428-348 B.C.) and the Phaedo

Plato saw each person, like the world itself, as being divided in two.  A person consists of a soul/mind (the Greek word is psyche, as in psychology, and can be translated either way) and a body.  The world is divided by Plato into the physical, sensible (as in sense-able) world and the spiritual or ideal (as in idea) world of "Forms" or "Ideas".

In the Phaedo he says that philosophy is the attempt to separate the mind from the body, which misleads it.  Since death s the separation of the mind from the body, philosophy is in effect practice for death and philosophers should welcome death.  They should not, though, commit suicide, as that is morally wrong.   Only the true lover of wisdom and death can be truly virtuous, he argues, because only he/she will be courageous (others will fear death), be temperate (i.e. have control over bodily desires rather than being controlled by them), be wise (being free from the errors into which the body tricks one), and thus just (see notes on the Republic).  The idea that the virtues all stand (or fall) together like this is known as the doctrine of the unity of the virtues.

There are three main arguments in the Phaedo that attempt to prove that there is life after death.

The cyclical argument: All things go in cycles, so life and death go in cycles, so after death comes life again.

    BUT plenty of things do not seem to go in cycles (cold cups of coffee do not automatically re-heat, etc.), and if we live life after life, why don't we remember these past lives? 

The argument from recollection: We have ideas, such as the idea of perfect equality, that could not have come from this world, since no two things in this world are perfectly equal; All ideas come from somewhere; So we must have got these ideas from another existence in another world (the world of forms); Therefore this life is not our only existence and we might live on in another world after death.

    BUT we might not, even if this argument is right; and perhaps all ideas do not come to the mind from outside, but are simply innate; and perhaps we could get ideas of perfection by extrapolating from the less perfect through the more perfect to the (imaginary) completely perfect--so the other world Plato refers to need not exist; or perhaps we get the idea of perfection by combining the idea of flaws (imperfections) with negation to get flawlessness.

The argument from the affinity of the soul with immortal things: Physical things are composite, changing, visible, naturally subject to rule by spiritual or ideal things, and die; spiritual/ideal things (e.g. gods, forms, numbers) are the opposite in every case; the mind clearly belongs to the second category and so is immortal.

    BUT must these be the only kinds of things there are?; does the mind really have no parts?; can't it change?; does the body rule the mind or does the mind rule the body?; why can't the mind be like immortal things in some ways (e.g. in being invisible) but unlike them in others (e.g. in being mortal)?