Speusippus

( c. 410 B.C. - 337 B.C.)

Biography

            Speusippus was Plato’s nephew, the son of Plato’s older sister Potone.  His father was Eurymedon, about whom nothing is known.  He was an Athenian citizen and took over Plato’s Academy for eight years after Plato’s death.  There is no record that he married or had children. 

            Nothing is known of Speusippus’ early life, and what we know about him at all is through some references made by his contemporaries.  The first time he appears in history is when he accompanied Plato on a trip to Syracuse in 361, to visit the tyrant Dionysius and perhaps plead for the restoration of Dion, Dionysius’ exiled nephew who had become a student at the Academy.  It is interesting that Plato selected his nephew Speusippus as a companion for this trip, considering that Plutarch records a close relationship between Speusippus and Dion:

               Dion...bought a country place, and afterwards...he gave this to Speusippus, who was his most intimate friend at Athens.  For Plato wished that Dion's disposition should be tempered and sweetened by association with men of charming presence who indulged seasonably in graceful pleasantries.  And such a man was Speusippus.  (Dillon 32)

It appears that not only did Plato think highly of Speusippus, but others did as well: Dion considered him a friend, and Plutarch’s source for this information was Timonides, who dedicated a history of Dion’s military campaigns to Speusippus.  Another anecdote recorded by Aelian seems to imply that Speusippus was the “protector” of the aging Plato, a role that might have made sense considering that Speusippus assumed leadership of the Academy on Plato’s death in 347 (Dillon 3).    

            Speusippus was in charge of the Academy for only eight years before he seems to have developed some kind of debilitating paralysis.  Diogenes Laertius records that Speusippus sent for Xenocrates, another of Plato’s pupils, to ask him to take over the school, and that Speusippus ended his own life.  He was approximately 70 years old when he died.

Central ideas

            Speusippus is identified with Pythagoreanism, “the postulation of a mathematical model of the universe,” and a philosophical system that seems to have been more attractive to Plato in his later years (Dillon 17).  The Pythagoreans “held things to be themselves numbers, because they thought they discovered in them many numerical determinations” (Zeller 574).  Mathematics, especially geometry, was held to reveal an eternal and ordered universe.  Although interest in this philosophy seems to have fallen off after Speusippus’ death, there was a later resurgence of interest in Pythagoreanism in the first century A.D.

            Diogenes Laertius records that Speusippus wrote an impressive number of dialogues, essays and treatises: he lists about 30 titles, and attributes 43,475 lines to Speussipus.  The titles of the works indicate that Speusippus wrote a great deal on ethics and mathematics.  Unfortunately, none of Speusippus’ work has survived.  A fragment of a work called On Pythagorean Numbers has been attributed to him, and it is possible that some of his work is quoted by Iamblichus (Dancy).  Everything that is known about Speusippus’ epistemology comes from references made by others.  Diogenes Laertius records that Speusippus “always adhered to the docrines which had been adopted by Plato,” but this may not be entirely true.  Russell Dancy argues that Speusippus rejected the Theory of Forms, and that from inference it seems he departed somewhat sharply from Plato’s teachings, more so than Xenocrates.

            Speusippus’ epistemology seems to have shared some elements with Aristotle’s: he claimed that there was knowledge at the level of perceived objects, and that to know something was to define it clearly (Dancy).  However, he seems to have held a strict interpretation of “defining:” to define something clearly one must be able to situate that thing correctly among all other items, to know every difference that separated it from others.  In the spirit of being able to define accurately and completely, he developed further classifications and divisions for things.  Dancy explores references in Sextus Empiricus and Athenaeus to two of Speusippus’ lost books, titled Definitions and Likes, which were apparent attempts to connect as many species of plants and animals as possible, differentiating some of them using criteria that differed from Aristotle’s (such as locale).  This would seem to be an almost impossible task, to define animals and plants by properly diagramming them in relation to every other known animals or plant in the same division, but Speusippus seems to have undertaken to do just that in the spirit of “defending a rather drastic position” on knowledge and knowing via definition (Dancy). 

Significance in the study of rhetoric

            From references made to Speusippus, we can determine that before Plato’s death he was “acknowledged as one of the key figures in the Academy, if not already the designated successor” (Dillon 33).  References in the works of his contemporaries indicate that he wrote a great deal and that other writers of the time were in dialogue with his ideas.  He and Xenocrates led the Academy as it transitioned from a gathering of Plato’s students, to those who only knew Plato’s writing.  In reading the many references made to him, it seems that if we had Speusippus’ writing we might understand a great deal more about the intellectual debates and dialogues of Plato’s time.  We can sense him in the background, as Russell Dancy concludes, “it is plain that the understanding of some of what is going on in late Plato would be aided by an understanding of what was going on in Speusippus.  The loss of his writings is regrettable indeed.”   

Works Cited

Dancy, Russell, "Speusippus," The Stanford Encyclopedia of Philosophy (Winter 2012 Edition), Edward N. Zalta (ed.)  Web.  29 October 2014.

Dillon, John.  The Heirs of Plato: A Study of the Old Academy (347-274 BC).  Oxford: Calendar Press (Oxford U), 2003.  Print.

Laertius, Diogenes.  Lives of Eminent Philosophers.  Transl. R.D. Hicks.  Cambridge: Harvard UP, 1970.  Print.

Zeller, Eduard.  Plato and the Older Academy.  Transl. Sarah Frances Alleyne and Alfred Goodwin.  Russell and Russell: New York, 1962.  Print.