II
There is less agreement about the antecedents of
ancient skepticism. Skeptical tendencies, real or
alleged, in pre-Socratics, Sophists, and Socrates were
traced by Victor Brochard in his Introduction. They
include the many comments of the early philosophers
on the unreliability of sense perception and the limita-
tions of human knowledge. Prominent in this review
are Gorgias, On Nature, or the Non Existent, and the
famous dictum of the Democritean Metrodorus of
Chios (fourth century B.C.), “We know nothing, not
even whether we know or do not know, or what it
is to know or not to know, or in general whether
anything exists or not” (Diels and Kranz, frag. B1).
Metrodorus' name is often linked with that of
Anaxarchus, the teacher of Pyrrho.
Among the ancients themselves, Plutarch (Moralia
1121F-1122A) says that Arcesilaus was accused of
having invoked the names of Socrates, Plato,
Parmenides, and Heraclitus as authorities for his skep-
tical views about the suspension of judgment and the
fallibility of apprehension; and Cicero, in speaking
for the Academy, includes Anaxagoras, Democritus,
Metrodorus, Empedocles, Parmenides, Xenophanes,
Socrates, and Plato in similar contexts (Ac. II.72-74;
Ac. I.44). Even more extravagant boasts, including not
only philosophers but in addition Homer, Archilochus,
Euripides, and Hippocrates are reported by Diogenes
Laërtius (IX.71-74). These exaggerated claims appear
to be a feature of Academic rather than Pyrrhonic
Skepticism; and indeed three of the ancient names for
skeptics, skeptikoi (“examiners”), zetetikoi (“searchers”),
and aporetikoi (“doubters”) were probably meant to
suggest a tie with the Platonic Socrates and perhaps
even with Aristotle. (On the names see NA XI.5; PH
I.7; DL IX.69-70. Aristotle appears as a skeptic in the
Epicurean Diogenes of Oenoanda, ed. Chilton, frag.
4.) Arcesilaus was called skeptikos by Timon and others,
according to Eusebius (PE XIV.6.5). He may have had
a polemical aim in thus placing himself in the main-
stream of Greek thought, in opposition to his chief
antagonist, the Stoic Zeno, a non-Greek from Cyprus.
No doubt Arcesilaus also found much useful material
in the arguments of his predecessors, especially the
Platonic Socrates (cf. Or. III.67).
The attitude of the Pyrrhonists toward the earlier
philosophers is less clear. Timon is reported to have
dedicated his Silloi to Xenophanes (cf. PH I.223-4; DL
IX.18, 111), and he seems to have spared the Eleatics
from his general abuse of the dogmatists (cf. DL IX.23,
25). Perhaps he did so out of regard for Pyrrho's
teacher Bryson; the Megaric School, to which Bryson
belonged, was influenced by the Eleatics. Timon also
spoke favorably of the atomist Democritus and the
Sophist Protagoras (DL IX.40, 52). His generally
mocking tone, however, makes even his praise
ambiguous.
Aenesidemus had a physical theory based on
Heraclitus. He held, according to Sextus (PH I.210),
that skepticism is the path to the Heraclitean philoso-
phy. Sextus, however, rejected this view and carefully
distinguished between Heraclitean dogmatism and
true skepticism. He also rejected the claims that
Democritus, the Cyrenaics, Protagoras, Socrates, Plato,
Xenophanes were skeptics. Even Carneades, in his
view, does not entirely escape the charge of dogmatism
(PH I.210-31).
