unreasonable.

Plato

In the first half of the fourth century, Plato adapted the most fruitful ideas of his predecessors into a comprehensive metaphysical scheme. The philosopher Alfred North Whitehead famously commented that the whole of Western philosophy consists of a series of footnotes to Plato. Certainly, his enquiries into ethics, politics, metaphysics and epistemology continue to influence Western thought today.

In most of his dialogues, Plato uses Socrates as the mouthpiece for his ideas. There has been much debate over the accuracy of this portrait of Socrates: it seems likely that in the earlier works the ironic and questioning Socrates owes something to the original, but most of Plato’s theories go far beyond anything the historical Socrates would have asserted. Nevertheless, it is generally agreed that Plato’s philosophy is connected to that of Socrates in several ways: the Socratic method of questioning to reveal misunderstanding of concepts; a focus on ethical and political problems (“The unexamined life is not worth living” says Socrates in the Apology); and a deep distrust of existing democratic institutions. Plato was in his late twenties when the Athenians voted for Socrates’ execution.

Death of Socrates
The Death of Socrates by David

In Book VII of the Republic, Plato draws a picture that serves as an analogy for the most important elements of his philosophy. He describes an underground cave with a flat back wall; facing this wall sit prisoners who can only look straight ahead. They are watching shadows dancing on the wall in front of them, but they cannot turn and look behind them: if they could, they would see that the shadows are cast by puppets being manipulated in front of a fire. For these prisoners, the shadows represent the whole of reality and they suspect nothing of their true origin. Plato then asks us to imagine a prisoner who escapes his restraints and turns around. After being momentarily blinded by the fire, he would perceive the source of the shadows and understand that the puppets are the real world of which the shadows are a poor imitation. If this prisoner then explores further, he will see another source of light spilling through a distant entrance. As he moves upwards and out of the cave (again being blinded by the brighter light) he will come to encounter the real world of objects outside the cave. To protect his vision, he will at first look down and see only reflections in water: but these reflections are more vibrant than even the puppets. As he accustoms himself to the bright light, he will slowly raise his eyes and encounter the real objects whose reflections he was admiring. Eventually, he will be able to look at the source of light itself: the sun.

The analogy of the cave should be understood as the progress of humans from ignorance to enlightenment. In an unreflective state, our attention is given to mere shadows (perhaps the flickering images on a television would be a more modern version): this is Heraclitus’ changing world of appearances. Gradually we learn to seek out higher truths, until at last we are able to see the ultimate reality behind appearances – this is Parmenides’ One Being. This ultimate reality bears the same relation to our unreflective ideas as a living person bears to the shadow of a carved puppet. Of course, it is neither easy nor always pleasurable to emerge from the darkness, and only a certain type of person can achieve such a goal. That person is a philosopher.

For Plato, the intellectual world – the realm of pure conceptual thought – is vastly superior to the observable world. The intelligible world produces knowledge, the visible world merely illusion and opinion. This distinction owes something to mathematics, where the approximate triangles and circles of the visible world are less ‘true’ than the ideal shapes of geometry from which we derive our formulae. The ‘Two-Worlds Theory’ was also intended as a solution to the problem of universals. There are many beautiful things in the world, but what do they have in common? What is the property they share that allows them to be described as beautiful? Plato’s solution was to say that they share in the ‘Form’ or ‘Idea’ of Beauty, an abstract entity which is unchanging and eternal. Such Forms exist only in the intelligible realm: while ordinary people stare at beautiful things, philosophers contemplate ‘true’ Beauty. Clearly there must be many Forms in the intelligible realm: Beauty, Goodness, Justice – even the Form of a Bed. Individual instances of beautiful, good, just things (and beds) partake in their Forms to a greater or lesser extent and can be the subject of opinion. But real, objective knowledge is only to be found in the realm of the Forms.

The Theory of Forms underlies all of Plato’s thinking. Since the soul (following Pythagoras) is also eternal, its proper home is the realm of the Forms. It preserves a faint memory of this realm when it is embodied: hence, for Plato, all knowledge is in fact recollection of the Forms. The theory is also the basis for the Platonic idea of love. Although the unenlightened grasp at physical beauty, true love is contemplation of the Form of Beauty, hence an idealised, non-physical engagement. There is also an implication for aesthetics. Since the mimetic Arts represent the visible world, they are one stage further removed from the true world of Forms: a painting of a bed is an imitation of a ‘real’ bed, which is itself an imitation of the Form of a Bed. Consequently, the Arts are deceptive illusions that seduce men from the path of knowledge. In Plato’s ideal Republic, the Arts are more or less forbidden.

The political implications of Plato’s system are far-reaching. Since only the philosophers have attained knowledge by contemplating the Forms, only the philosophers have the wisdom (if not the inclination) to return to the cave and instruct and guide their fellow citizens onto the true path. In other words, the state (polis) should be ruled by Philosopher Kings. Plato despised democracy as a political constitution, not least because the Athenian democracy voted to execute Socrates. Perhaps more importantly, he thought that ordinary citizens lack philosophical knowledge, and are therefore ill-equipped to make laws and choose policies (a criticism still taken seriously today). The superior understanding of philosophers, however, gives them the ability to decide what is best for all citizens. The just state also provides an analogy for the just individual. In Plato’s Republic there are three classes: the Philosopher Kings who rule the state, the Soldiers who defend the state, and the Workers who provide material goods for the state. Similarly, the human soul should be guided by its reason, defended by its spirit, and fed by its appetites. When these three elements are in obedient harmony, the soul and the state are considered just (or, in other words, such souls and states approximate most closely to the Form of Justice). It is worth noting that Plato attempted to realise his ideal of the Philosopher King in the person of Dionysius II, the young tyrant of Syracuse. The attempt, perhaps unsurprisingly, was a spectacular failure.

The systematic and comprehensive nature of Plato’s thinking made it suited to a more collaborative environment, and accordingly he established one of the first organised ‘schools’ in Athens. The Academy continued as a Sceptical and later Neoplatonic school until its closure in the sixth century AD as a threat to Christianity.

Aristotle

The works of Aristotle, even more than those of Plato, defy summary. He explored ethics and politics, metaphysics, logic and epistemology, music, astronomy, zoology, physics, mathematics, psychology, theology, literary theory and much else in around 200 works, of which 31 survive. These extant works are mostly drafts or lecture notes and do not make easy reading. Nevertheless, Aristotle’s influence matches Plato’s: he was the philosopher of choice for the Middle Ages and his treatment of ethics is still being discussed today.

Born in Stagira in Macedon (and hence known as the ‘Stagirite’), Aristotle came to Athens to study in Plato’s Academy. Later he was summoned back to Macedon to become tutor to the 13-year-old Alexander the Great. With this duty done, he returned to Athens to establish his own school, the Lyceum, whose followers would become known as ‘Peripatetics’ from the colonnades (peripatoi) where they met. After Alexander’s death, he fled Athens lest the city that had executed Socrates “sin twice against philosophy” and died the following year.

Aristotle
Aristotle

Aristotle was as much a scientist as a philosopher, and accordingly his method was primarily empirical rather than rationalist. In this he differed profoundly from Plato. Aristotle preferred the evidence of the phenomenal world: he catalogued and categorised many aspects of nature, and took the time to make some excellent and intricate observations in zoology. Plato’s heavenly Forms became, for Aristotle, formal causes closely wedded to the objects of experience. He defined substance as composed of matter and form, relocating Plato’s second world firmly back in the first. His rejection of the Theory of Forms is his most dramatic departure from Plato’s teachings, but was based as much on reasoning as on his empiricist temperament. He resurrected an objection mentioned by Plato in the Parmenides that has become known as the ‘Third Man Argument’. According to the Theory of Forms, a man can be described as a man because he partakes in the ideal Form of Man. But we now have a group of two things that share the predicate ‘man’, namely the individual man and the Form of Man. For Plato, two things share a predicate if they partake in a Form: in this case, we need a third entity in which both ‘man’ and ‘Man’ partake. The argument is, of course, infinite: we now have three entities which share a predicate, and so on. Although Plato did not regard this argument as decisive, Aristotle did and consequently rejected this central element of Plato’s system.

At the heart of Aristotle’s method is the demand that any explanation in science or philosophy must meet certain robust criteria. In the Physics he suggests that if we were to discover a bronze statue we would be led to ask four questions about it: what is it? what is it made of? what created it? and what is it for? In Aristotle’s terminology we are seeking knowledge of the four causes: formal, material, efficient and final. The formal cause might be the shape of an athlete; the material cause, bronze; the efficient cause, the artist who sculpted it; and the final cause, to honour the athlete portrayed. An account of all four causes constitutes an adequate explanation. The Presocratics, for instance, in identifying the various elements and the forces that bind them, addressed only the material, formal and efficient causes of the universe. Aristotle’s enquiry is therefore more thorough as it also addresses the final causes of things. By asking what is it for? Aristotle raised some fascinating philosophical questions: when applied to ethics, it is no less than the meaning of human life. The final cause of human life for Aristotle was eudaimonia, an untranslatable term that implies happiness, fulfilment and general flourishing of talents. By developing certain dispositions or virtues, a person can achieve eudaimonia just as a well-made statue can triumphantly honour its subject. This theory of virtue-based ethics was revisited in the twentieth century and is of great contemporary interest to ethical philosophers. There are political implications to this theory, too: like Plato, Aristotle was no fan of democracy and considered it a deviant form of political organisation as it does not meet the goal of developing human talents.

Perhaps the most enduring of Aristotle’s achievements is his account of the formal structure of logical reasoning. He developed the syllogism as a model of deductive logic: All men are mortal, Socrates is a man, therefore Socrates is mortal is an example of a valid syllogism. By varying these simple elements (eg replacing all with some) different values arise. Aristotle’s analysis of this type of reasoning was generally considered complete and went unchallenged for over two millennia.

Probably the most widely read of Aristotle’s works is the Poetics in which he explores the form and effects of Tragedy (the second book on Comedy is now lost). He explains the effect of Tragedy as the evocation of pity and fear, leading to a catharsis, or purification of these emotions. In his aesthetic theory, Aristotle was defending Tragedy against Plato who had condemned it as a dangerous illusion.

School of Athens
Plato and Aristotle in The School of Athens by Raphael

Writing about the twenty years Aristotle spent at Plato’s Academy in Athens, Anthony Kenny notes:

... it can safely be said that on no other occasion in history was such intellectual power concentrated in a single institution.

History has borne out this dramatic claim. Without Plato and Aristotle the development of Western philosophy is hard to imagine. In one sense their differences are more suggestive than their agreements: Plato is the idealist, a mystic with his gaze directed to the heavens; Aristotle the realist, a scientist with his attention drawn to the world around him. The ascendancy of one or other of these approaches to enquiry would characterise Western thought for the next two thousand years.

Sources

« »