The Argument from Opposites

Socrates proposes the first argument for the soul's immortality: from the cycle of opposites. In nature, all things with opposites are generated from those opposites. The larger comes from the smaller; the stronger from the weaker; the beautiful from the ugly; the awake from the asleep. The law is universal. Life and death are such a pair.

If this law holds, then just as the dead come from the living, the living must come from the dead. The process must be circular — a genuine back-and-forth — or else everything would eventually drain to one pole. If everything died and nothing were reborn, the universe would long since have become a single pool of death. Souls must persist after death, in some form, so that the living can be born from them.

Cebes confirms that this follows, and adds that Socrates has always taught them a related doctrine: that learning is recollection. We recognize equality, beauty, justice — abstract things we have never encountered in their pure form in this life — which suggests we knew them before birth and are now remembering. Both arguments point the same way: the soul existed before the body. If it existed before, the case for its surviving after becomes easier to make. Socrates says they should consider both arguments together.