Speusippus | Today's AI Wiki

1. Life

Speusippus's life was closely intertwined with that of his uncle, Plato, and his succession to the leadership of the Academy marked a pivotal moment in the school's early history.

Speusippus was born in Athens around 408 BC. His parents were Eurymedon and Potone, who was Plato's sister. He belonged to the deme of Myrrhinus. According to the pseudonymous Thirteenth Letter of Plato, Speusippus married his niece, who was his mother's granddaughter.

1.2. Relationship with Plato and Visit to Syracuse

Speusippus's public life became notable when he accompanied his uncle Plato on his third journey to Syracuse. During this period, he demonstrated considerable ability and prudence, particularly in fostering amicable relations with Dion. His cooperation with Dion played a role in the banishment of Dionysius the Younger. Despite later reports of his sudden fits of anger, greed, and debauchery, these accounts are likely derived from unreliable sources, such as spurious letters attributed to Dionysius the Younger, who was exiled with Speusippus's assistance. Even Timon, a critic, acknowledged Speusippus's moral worth, though he ridiculed his intellect.

1.3. Head of the Academy

Upon Plato's death in 348/7 BC, Speusippus was chosen as his successor to lead the Platonic Academy, becoming its second scholarch. He was approximately 60 years old when he assumed this role. He headed the school for eight years, until 339/8 BC. During his leadership, Speusippus significantly steered the Academy's direction, notably by moving away from some of Plato's core doctrines. His emphasis on mathematical objects as primary reality and his leanings towards Pythagoreanism led to Aristotle's departure from the Academy.

1.4. Death and Succession

Speusippus's health declined in his later years, and he suffered from a lingering paralytic illness, presumed to be a stroke. He died around 339/8 BC. Following his death, the leadership of the Academy passed to Xenocrates, who became the third scholarch.

2. Philosophy

Speusippus's philosophy represented a significant evolution and, in some respects, a departure from Plato's original teachings. His work delved into metaphysics, epistemology, and ethics, often incorporating elements from Pythagorean thought.

2.1. General Philosophical Tendency

Speusippus's philosophy was characterized by its attempts to harmonize Platonism with other philosophical traditions, particularly Pythagoreanism. He placed a strong emphasis on mathematics, viewing mathematical objects as primary realities, a stance that diverged from Plato's Theory of Forms. He rejected the absolute nature of Plato's Ideas, instead perceiving a path to the One through the recognition of regularity in number systems and the identification of integers. This perspective led to some opposition from traditional Platonists, as it implicitly challenged the absolute nature of Plato's Forms. His approach was considered somewhat mystical by some contemporaries. He also furthered the threefold division of philosophy into Dialectics, Ethics, and Physics, acknowledging their mutual connection.

2.2. Metaphysics

A central tenet of Speusippus's metaphysics was his rejection of Plato's Theory of Forms and ideal numbers. While Plato distinguished between ideal numbers and mathematical numbers, Speusippus rejected the former, thus discarding the ideal Forms. He sought to define substance more distinctly by categorizing its types based on their underlying principles. He identified distinct substances of number, size, and soul, whereas Plato had linked these to ideal numbers as separate entities. Speusippus posited that the absolute One was a formal principle common to these different types of substances and that multitude and multiformity were common primary elements in their composition.

Furthermore, Speusippus diverged from Plato by not recognizing the Good as the ultimate principle. Instead, he argued that the Good was a result of generated existence or development, similar to how fully formed plants or animals develop from seeds. He designated the ultimate principle as the absolute One, but crucially, he did not consider it an existing entity, as all entities are products of development. While he aligned with the Pythagoreans in including the One in the series of good things, he likely conceived it in opposition to the Many, suggesting that the good and perfect originate from the One rather than the Many. Speusippus also seemed to attribute vital activity to this primordial Unity, explaining its capacity for self-development into goodness and spirit. He distinguished spirit from the One and the Good, and the Good from pleasure and pain. His efforts to find a more suitable expression for the material principle, which Plato termed indefinite duality, and his Pythagorean approach to number doctrine are evident in his writings on Pythagorean numbers.

2.3. Epistemology

Speusippus was deeply interested in the systematic classification of philosophical concepts, particularly in deriving and establishing the ideas of genera and species. He believed that a complete definition of any object could only be achieved by understanding all the differences that separate it from everything else.

Like Plato, Speusippus differentiated between objects of thought and objects of sensuous perception, and between rational cognition and sensory perception. However, he attempted to bridge this gap by positing that perception could be elevated to knowledge through its participation in rational truth. He suggested an immediate, perhaps aesthetic, mode of conception, citing artistic skill as an example. He argued that artistic skill is not merely sensuous activity but stems from an unerring power of distinguishing between objects, which he considered a rational perception.

In the realm of aesthetics, Speusippus emphasized the absolute power of reason in classifying 'beauty.' He viewed sensory cognition as immediate and unilateral, a mere stimulus incapable of higher judgments such as good versus evil, happiness versus unhappiness, or beauty versus ugliness. For Speusippus, feeling 'beauty' or 'ugliness' towards something inherently involved judgment, and such judgment could only arise as a result of rational thought. Therefore, even aesthetic activities like poetry and art are ultimately governed by reason. This perspective, which integrates reason into aesthetic judgment, contrasts with Plato's view that poetry and art should be excluded because they incite passion.

2.4. Ethics

Speusippus's ethical theories touched upon concepts of justice, friendship, pleasure, and wealth. He defined happiness as "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 definition suggests a foundational influence on later ethical schools, such as the Stoics (with their emphasis on conformity with nature) and the Epicureans (with their pursuit of "freedom from disturbance," or ataraxia).

He engaged in a notable polemic with Eudoxus of Cnidus, who identified the Good with pleasure. Speusippus, in contrast, insisted that pleasure was not a good in itself. He argued that the Good exists "in between the opposites of pleasure and pain." This dispute between Speusippus and Eudoxus is thought to have influenced Plato's dialogue Philebus. Speusippus also further developed Plato's ideas concerning justice, the role of the citizen, and the fundamental principles of legislation. He contended that the Good is not a principle that generates things but is determined when things ultimately take on their form. From this perspective, he believed that the principle of Good is inherent even in natural objects. He logically sought to demonstrate that the Good is strongly dependent on the One, and that the Dyad (Two), which is derived from the One, is also a part of the Good. Consequently, he concluded that pleasure, being a faint entity far removed from nature, is inherently 'evil'.

3. Works

Diogenes Laërtius provided a selection of Speusippus's works, noting that his complete writings amounted to 43,475 lines of manuscript. While many of his works are now lost and survive only in fragments, the titles indicate the breadth of his philosophical interests.

Aristippus of Cyrene
On Wealth, one book
On Pleasure, one book
On Justice
On Philosophy
On Friendship
On the Gods
The Philosopher
A Reply to Cephalus
Cephalus
Clinomachus or Lysias
The Citizen
Of the Soul
A Reply to Gryllus
Criticism of the Arts, one book for each art
Memoirs, in the form of dialogues
Treatise on System, in one book
Dialogues on the Resemblances in Science, in ten books
Divisions and Hypotheses relating to the Resemblances
On Typical Genera and Species
A Reply to the Anonymous Work
Eulogy of Plato
Epistles to Dion, Dionysius and Philip
On Legislation
The Mathematician
Mandrobolus
Lysias
Definitions
Arrangements of Commentaries
On Similarities (Ὅμοια_Homoia^{Greek, Ancient})
On Pythagorean Numbers

4. Influence and Evaluation

Speusippus's philosophical contributions and his leadership of the Academy had a significant impact on the development of ancient Greek philosophy, particularly within the Platonic tradition, even as his ideas drew criticism from contemporaries like Aristotle.

4.1. Criticism by Aristotle

Speusippus, depicted as a medieval scholar in the Nuremberg Chronicle — Speusippus, depicted as a medieval scholar in the *Nuremberg Chronicle*

Speusippus's philosophical divergences from Plato, particularly his emphasis on mathematics and his rejection of the Theory of Forms, drew sharp criticism from Aristotle. Aristotle is famously quoted as having said, "For people today, mathematical studies have become philosophy," a remark widely believed to be directed at Speusippus. This departure from traditional Platonic doctrines, especially Speusippus's leanings towards Pythagoreanism and number theory, viewing mathematical objects as primary realities, was a decisive factor in Aristotle's decision to leave the Academy after Speusippus assumed its leadership. Aristotle's criticisms indicate his dissatisfaction with Speusippus's modifications of the original Platonist doctrine.

4.2. Succession in the Academy

Despite the criticisms and his own philosophical innovations, Speusippus's legacy within the Academy was carried forward by his successor, Xenocrates. Xenocrates continued to shape the direction of the Platonic Academy, inheriting and transforming aspects of Speusippus's philosophical thought within the broader framework of Platonism.