12.10 = T30) describes this system as “episodic” (i.e., like dramas consisting of a series of
disconnected episodes). It seems that, while beauty appears at the mathematical levels,
anything describable as “good” only appears at the level of soul. Speusippos explained the
creation in the Timaios as simply a didactic device, so we must suppose his picture of
successive stages of generation offered something other than a temporal account of how the
world came to be as it is. Speusippos’ explanation of soul in terms of the “Idea of the all-
extended” may also relate to the Timaios, but its significance is unclear. He seems to have
explained god as a soul-power governing all things, or an intellect (A 1.7.20 = T58),
again avoiding any transcendent divinities (C, Nat. D. 1.32 = T56).
In epistemology, Speusippos spoke of the “scientific” (episte ̄monikos) sensation expected of
experts in the use of the senses (S E, Adv. Math. 7.145–6). We must infer
that Speusippos was keen to show that scientific knowledge could be based on sensation, pace
Plato. A further innovation seems to be the claim, connected with the classificatory project,
that in order to know A, one must know also B, C, D, etc. from which A differs, since one
needs to know all the differentiae of A (Arist. An. Po. 2.13 = T63).
In ethics, he clearly tried to avoid the hedonistic argument that if pain is bad, its opposite
should be good, by appealing to something with a superficial resemblance to the doctrine of
the mean: extremes are opposed to the middle, as well as to one another (Arist. EN 7.12,
cf. 10.3 = T80–81). This suggests that the good is in fact a stable neutral state, rather than
any deviation from or return to it.
Other idiosyncrasies in the areas of mathematic and logic suggest an original thinker,
more scientific than Aristotle would allow, the loss of whose works is to be lamented.
Ed.: L. Tarán, Speusippus of Athens (1981).
Dillon (2003) 30–88.
Harold Tarrant
Sphairos of Borusthene ̄s (260 – 210 BCE)
Stoic philosopher and student of Z K and K A. Advisor
or teacher to Kleomene ̄s III of Sparta, he later participated in the courts of Ptolemy IV
Philopato ̄r (D L, 7.177) and of at least one of Ptolemy’s immediate pre-
decessors, Ptolemy III Euerge ̄te ̄s, or Ptolemy II Philadelphos (D.L., 7.185, is unspecific and,
given the dates of the participants, the Ptolemy who wrote to Kleanthe ̄s could have been
either Ptolemy II or III). Diogene ̄s Laërtios (7.178) ascribes 31 titles to him, including a set
of lectures on H and books on a range of topics in ethics, physics, and logic.
Very little else is known about his philosophy, although a few reports offer some hints.
C (Tusc. 4.53) says that the Stoics considered Sphairos particularly good at def-
initions, and Diogene ̄s Laërtios (7.177) recounts a story about Ptolemy IV tricking Sphairos
with a wax pomegranate to show that a philosopher might assent to a phantasm (where
Sphairos had argued that the wise man would not assent to an opinion). Sphairos countered
that he had only assented to the fact that the pomegranate appeared real, not that it actually
was real.
Ed.: SVF 1.620–630.
Daryn Lehoux
SPHAIROS OF BORUSTHENE ̄S