much they may ascend to the ideal, the discussions all start in the real world of
practical human concerns.
It is not only the setting over which Plato takes pains. When he introduces
Aristophanes in the Symposium,the comic poet speaks very much in character (one
to which Plato seems well disposed), offering an entertaining fantasy in which Zeus
cut the original human beings in half to punish them, with the result that love is the
search for the lost half, ‘the desire and pursuit of the whole’ (189–193). What starts
as a joke after the more scientific lecture delivered by the previous speaker proves
to be the most thought provoking speech of the first half of the colloquium, in the best
serio-comic Aristophanic style. There is a pointed contrast of character in the
Republic, when, after the polite and careful cross-questioning of the sweetly reason-
able Socrates, the abrupt denunciation of him by the opinionated and dogmatic
sophist, Thrasymachus, comes as a dramatic surprise (336b). The portrayal of him is
deliberately extreme; the contrasting example of the sophist throws the superior
qualities of Socrates’ mind, motive and method into clear relief.
Akey to the whole tendency of Plato’s thought, in particular to the sharp
distinction he makes between the ideal and the phenomenal world, can be found in
the famous allegory of the cave in the sixth book of the Republic (513e–518). This is
a graphic representation of the tendency in Greek thought to find the source of human
happiness and virtue in knowledge and to exalt the wise man as the enlightener and
saviour of mankind, opening up the possibility of a steep and arduous upward road
to truth through the application of human intelligence and the exercise of the power
of reason.
The allegory of the cave is designed to be a figurative illustration of Plato’s theory
of knowledge. Socrates has been arguing that the true philosopher is not content to
study a variety of beautiful objects, but seeks to know what beauty is in itself, what is
called the ‘form’ (eidos) or ‘idea’ (idea) of beauty (Republic, 476).
In Plato’s theory there are forms of abstract things, like beauty, goodness and
justice, and of physical things, like beds and tables. These forms transcend the phe-
nomenal world of sense impression, that is the world that we perceive through our
senses of sight, hearing, touch, smell and taste. They exist apart and are eternal and
unchanging. The phenomenal world in some way participates in this greater tran-
scendent world of forms: a beautiful object is informed by beauty itself; a bed shares
in the non-physical reality of the ideal bed. Only the forms are the objects of true
knowledge. He who apprehends merely the particularities of the phenomenal world,
apprehends mutable appearances, what seems to be true. He does not have
knowledge, but has opinion (doxa: the Greek word has the same root as the word
dokein, to seem). The ultimate end of knowledge is the form of the good, which gives
meaning and value to everything in the universe. When asked to be more precise
about this supreme reality, Socrates confesses that he is unable to be so, and resorts
PHILOSOPHY 197