effects of the arguments propounded by the Eleatic thinkers Parmenides and Melissus. They proved, by
an argument that nobody could fault, a conclusion that nobody could believe: that although it appears to
us that we refer to a plurality of qualified and changing objects, in reality there is only one thing to be
referred to, and to conceive of this as qualified, divided, or pluralized in any way is to imply absurdities.
Until Plato and Aristotle nobody challenged the actual arguments, but the conflict they forced between
the results of reasoning and the assumptions of experience was taken to heart in two ways. First,
traditional philosophizing, mainly occupied with explanation of the •world, was jolted into self-
consciousness about the issues of reality and appearance and, relatedly, of reasoning and experience.
Fifth-century cosmologies show continued confidence in our reasonings about explanation and the
ultimate constituents of things; but confidence in the phenomena to be explained has gone. In deference
to the Eleatic arguments the world of our experience is thought of as mere appearance, and theories
become, for the first time, reductive: they tell us what is really there (atoms and void, for example) and
the world of our experience is consigned, mysteriously, to mere convention. Anaxagoras criticizes as
wrong the common-sense belief that things come into being and perish; the truth is no longer available
to us without philosophers' theories, and it comes to be taken for granted that philosophical thinking
reveals a contrast between reality, displayed by theory, and the world as it appears to us, which we pre-
reflectively accept. But we find a record of puzzles on this topic rather than solutions; it is not a primary
interest for any thinker until Plato.
The outrageousness of the conclusions of Eleatic argument produced another striking development: a
new awareness of argument itself, and its use and abuse. It was a novelty when Zeno of Elea, in defence
of Parmenides, produced a whole book consisting solely of arguments. It was even more of a novelty
when Gorgias of Leontini (C.485-C.380) produced a book proving by argument that there is nothing,
that if there were we couldn't understand it, and if we could we couldn't communicate it. We admire the
ingenuity of Gorgian argument while remaining unsure of his commitment either to its validity or to the
truth of the conclusion.
At a time when such detachment was new, this could easily strike people, and did, as disturbing and
irresponsible. By the time of Aristophanes' Clouds cleverness in argument is feared, but it is perceived
as a dubious talent, likely to go with indifference to the truth of what is in dispute. This was a sad state
of affairs, largely due to confusions about the nature of argument which were not definitively cleared up
till Aristotle. But that the suspicions were often deserved can be seen from such a text as the fifth-
century Dissoi Logoi or 'Double Arguments'. In it arguments are listed pro and con a number of theses;
interesting arguments and feeble fallacies are indifferently lumped together; and there is no attempt to
understand the grounds or point or mutual relations of any of the theses.
Gorgias was one of the first of the 'sophists', teachers who went round various cities offering, for a fee,
the only available 'higher education'. Other famous sophists were Protagoras (c.490-421), Prodicus
(c.460-390 s), Hippias (roughly contemporary with Prodicus), Antiphon and Thrasymachus (both
difficult to date but active in the late fifth century), Alcidamas and Lycophron (late fifth century, the
former a pupil of Gorgias). As well as further instruction in subjects like mathematics, the sophists
taught 'rhetoric', the art of arguing convincingly, irrespective of subject-matter. Their services were
welcome because the art of arguing other people down was useful in the highly public arena of city