(c. 407 BC – 339 BC) was an ancient Greek philosopher
. Speusippus was Plato
's nephew by his sister Potone
. After Plato's death, Speusippus inherited the
Academy and remained
its head for the next eight years.
However, following a
stroke, he passed the chair to Xenocrates
. Although the successor to Plato in
the Academy, he frequently diverged from Plato's teachings. He
rejected Plato's Theory of Forms
and whereas Plato had identified the Good
with the ultimate principle
Speusippus maintained that the Good was merely secondary. He also
argued that it is impossible to have satisfactory knowledge
of any thing without knowing all the
differences by which it is separated from everything else.
was a native of Athens, and the son
of Eurymedon and Potone, a sister of Plato. We hear nothing of his life until the time
when he accompanied his uncle Plato on his third journey to
Syracuse, where he
displayed considerable ability and prudence, especially in his
amicable relations with Dion.
His moral worth is recognised
even by Timon
, though only that
he may heap the more unsparing ridicule on his intellect.
The report about his sudden fits of anger, his greed, and his
debauchery, are probably derived from a very impure source:
and Diogenes Laërtius
can adduce as
authority for them scarcely anything more than some abuse in
certain letters of Dionysius the
, who was banished by Dion, with the cooperation of
Speusippus. Having been selected by Plato as his
successor as the leader (scholarch) of the Academy, he was at
the head of the school for only eight years (347-339 BC.).
He died, it appears, of a lingering paralytic illness, presumably a
. He was succeeded as the head of the
school by Xenocrates
gives us a
list of some of the titles of the many dialogues and commentaries
of Speusippus, which is of little help in determining their
contents, and the fragments provided by other writers provide us
with only a little extra.
Speusippus was interested in bringing together those things which
were similar in their philosophical treatment, and to the
derivation, and laying down, of the ideas of genera
: for he was
interested in what the various sciences had in common, and how they
might be connected. Thus he furthered the threefold division of
philosophy into Dialectics
, and Physics
, for which
Plato had laid the foundation, without losing sight of the mutual
connection of these three branches of philosophy. For he maintained
that noone could arrive at a complete definition who did not know
all the differences by which a thing which was to be defined was
separated from the rest.
With Plato, moreover, he distinguished between that which is the
object of thought
, and that which is the
object of sensuous perception
the cognition of the reason and sensuous perception. He tried,
however, to show how perception can be taken up and transformed
into knowledge, by the assumption of a perception, which, by
participation in rational truth, raises itself to the rank of
knowledge. By this he seems to have understood an immediate, (in
the first instance aesthetic), mode of conception; since he
appealed, in support of this view, to the consideration that
artistic skill has its foundation not in sensuous activity, but in
an unerring power of distinguishing between its objects, that is,
in a rational perception of them.
Speusippus rejected Plato's Theory of
; whereas Plato distinguished between ideal numbers (i.e.
the Platonic Forms of numbers) and mathematical numbers, Speusippus
rejected the ideal numbers, and consequently the ideas
. He tried to determine the idea of substance
more distinctly by separating its
types, the difference between which he considered would result from
the difference between the principles
which they are based. Thus he distinguished substances of number
, of size
, of soul
, while Plato had referred them, as separate
entities, to the ideal numbers.
Speusippus made still more kinds of substance,
beginning with the One, and assuming principles for each kind of
substance, one for numbers, another for spatial magnitudes, and
then another for the soul; and by going on in this way he
multiplies the kinds of substance.
Nevertheless Speusippus also must have recognised something common
in those different kinds of substances, inasmuch as, firstly, he
set out from the absolute One, and regarded it as a formal
which they had in common, and, secondly, he
appears to have assumed that multitude and multiformity was a
common primary element in their composition. But it is only the
difficulties which led him to make this and similar deviations from
the Platonist doctrine, of which we can get any clear idea, not the
way in which he thought he had avoided those difficulties by
distinguishing different kinds of principles
criticism of Aristotle
apparently against Speusippus, shows how little satisfied he was
with the modification of the original Platonist doctrine.
With this deviation from Plato's doctrine is connected another
which takes a wider range. As the ultimate principle
Speusippus would not, with Plato, recognise the Good
, but, with others, (who doubtless
were also Platonists), going back to the older Theologi
maintained that the principles
of the universe were to be
set down as causes of the good and perfect, but were not the good
and perfect itself, which must rather be regarded as the result of
generated existence, or development, just as the seeds of plants
and animals are not the fully formed plants or animals themselves.
Speusippus [supposes] that supreme beauty and goodness
are not present in the beginning, because the beginnings both of
plants and of animals are causes, but beauty and completeness are
in the effects of these.
The ultimate principle
he designated, like Plato, as the
absolute One, but it was not to be regarded as an existing entity,
since all entities can only be the result of development. When,
however, with the Pythagoreans
reckoned the One
in the series of good
probably conceived it only in its opposition to the Many
and wished to indicate that it was from the One
from the Many
, that the good and perfect is to be derived.
Nevertheless Speusippus seems to have attributed vital activity to
the primordial Unity, as inseparably belonging to it, probably in
order to explain how it could grow, by a process of
self-development, into the good, spirit, etc.; for spirit also he
distinguished from the one, as well as from the good; and the good
from pleasure and pain. Less worthy of notice is the attempt by
Speusippus to find a more suitable expression for the material
, the indefinite duality of Plato; and his
mode of treating the
doctrine of numbers which we can see in the extracts of his
treatise on the Pythagorean numbers.
Diogenes Laertius' list of Speusippus' works includes titles on
justice, friendship, pleasure, and wealth. Clement of Alexandria
(fr. 77 Tarán)
reports that Speusippus considered happiness
to be "a state that is complete in
those things that are in accordance with nature, a condition
desired by all human beings, while the good aim at freedom from
disturbance; and the virtues would be productive of happiness."
This testimony suggests that Speusippus' ethics may have been an
important background to ethical ideas of the Stoics
(the will's conformity with nature) and
(compare "freedom from
, with the notion of ataraxia
Modern scholars have detected a polemic between Speusippus and
Eudoxus of Cnidus
good. Eudoxus also accepts that the good will be that at which all
people aim, but identifies this as pleasure, as opposed to
Speusippus' exclusive focus on moral goods. Texts of Aristotle and
suggest that Speusippus
insisted that pleasure was not a good, but that the good was "in
between the opposites of pleasure and pain." It is possible that
the dispute between Speusippus and Eudoxus influenced Plato's
Speusippus also seems to have developed further Plato's ideas of
and of the citizen
, and the fundamental principles of
- Paul Lang, De Speusippi academici scriptis.
Accedunt fragmenta, diss. Bonn, 1911 (repr. Frankfurt
1964, Hildesheim 1965)
- Elias Bickermann and Johannes Sykutris, Speusipps Brief an
König Philipp: Text, Übersetzung, Untersuchungen, Berichte
über die Verhandlungen der Sächsischen Akademie der Wissenschaften
zu Leipzig: Philologisch-historische Klasse 80:3 (1928)
- Margherita Isnardi Parente, Speusippo:
Frammenti. Edizione, traduzione e commento, Naples:
Istituto Italiano per gli Studi Filosofici, 1980
- Leonardo Tarán, Speusippus of Athens: A Critical Study with
a Collection of the Related Texts and Commentary, Leiden:
- Anthony Francis Natoli, The Letter of Speusippus to Philip
II: Introduction, Test, Translation, and Commentary
(Historia Einzeschriften 176), Stuttgart: Franz Steiner,
- Diogenes Laërtius, iv.; Suda, Speusippos.
- Plutarch, Dion, c. 22. 17
- Plutarch, Dion, 17
- Athenaeus, vii., xii.
- Diogenes Laërtius, iv.; comp. Suda, Speusippos;
Tertullian, Apolog. c. 46.
- Diogenes Laërtius. iv.
- Diodorus, ap. Diogenes Laërtius, iv.
- Themistius, in Aristotle, Analytica Posteriora
- Sextus Empiricus, adv. Math. vii. 145 ff.
- Aristotle, Metaphysica, vii. 2, i. 6, xiii. 8-9
- Aristotle Metaphysica, vi. 2, 11, xii. 10, de
Anima, i. 2; Iamblichus, ap. Stobaeus, Eclog. i.
- Aristotle, Metaphysics, vii. 2
- Aristotle, Metaphysica, vi. 2, xiv. 3, xiii. 9
- Aristotle, Metaphysica, xiv. 4, 5, xiii. 7, xii. 10,
Ethica Nicomachea, i. 4; Cicero, de Natura
Deorum, i. 13 ; Stobaeus, Ecl. i.; Theophrastus,
- Aristotle, Metaphysics, xii. 7
- Aristotle, Metaphysica, xii. 7, ix. 8, xiv. 5
- Aristotle Ethica Nicomachea, i. 4
- comp. Aristotle, Metaphysica, xiv. 4, xii. 10
- Cicero, de Natura Deorum, i. 13
- Stobaeus, Ecl. Phys. i. 1; comp. Aristotle,
Metaphysica, xiv. 4, Ethica Nicomachea, vii.
- Aristotle, Metaphysica, xiv. 4, 5, comp. 2, 1, xiii.
- Russell Dancy, "Speusippus," Stanford Encyclopedia of