Plato Notes

Plato

Plato's Influence

• Plato's comprehensive treatment of knowledge significantly influenced Western thought.
• He unified diverse philosophical concerns into a coherent system.
• Earlier philosophers focused on specific problems:
  • Milesians: Physical nature.
  • Eleatics (Parmenides, Zeno): Unchanging, single reality (the One).
  • Heraclitus, Pythagoreans: Reality as change, flux, multitude.
  • Socrates, Sophists: Morality.

Plato's Life

• Born in Athens, 428/27 BCE.
• Family was distinguished, involved in arts, politics, and philosophy.
• Father's lineage traced to kings of Athens and Poseidon.
• Mother, Perictione, related to Charmides and Critias (oligarchy leaders).
• Stepfather, Pyrilampes, was a friend of Pericles.
• Family had ties to Solon (lawmaker) and an archon in 644 BCE.
• Developed a sense of responsibility for public political service early in life.
• Witnessed the failings of Athenian democracy during the Peloponnesian War.
• Socrates' trial and execution disillusioned him with democracy.
• Advocated for political leadership based on knowledge, like a ship's pilot.
• Developed this theme in his book, Republic.
• Founded the Academy in Athens around 387 BCE.
• The Academy was the first university in Western Europe.
• The Academy aimed at pursuing scientific knowledge through original research.
• Emphasized rigorous intellectual activity, including mathematics, astronomy, and harmonics, for future leaders.
• His contemporary Isocrates favored a practical approach, dismissing pure research.
• Mathematician Eudoxus united his school with Plato’s Academy.
• The execution of Socrates diverted him from public service.
• He taught that rulers should have rigorous knowledge and was invited to Syracuse to instruct Dionysius II, but was unsuccessful.
• Died in 348/47 BCE at the age of 80.
• Lectured at the Academy without notes; students circulated their notes.
• Composed more than twenty philosophical dialogues.
• Dialogues are commonly grouped into three periods:
  • Early writings (Socratic dialogues): Apology, Crito, Charmides, Laches, Euthyphro, Euthydemus, Cratylus, Protagoras, Gorgias (Ethics).
  • Middle writings: Meno, Symposium, Phaedo, Republic, Phaedrus (Theory of Forms, metaphysics).
  • Later writings: Theaetetus, Parmenides, Sophist, Statesman, Philebus, Timaeus, Laws (Technical, religious conviction).
• No single work presents a schematic arrangement of Plato's thought; dominant themes emerge from various dialogues.

Theory of Knowledge

• Plato’s philosophy is grounded in his account of knowledge.
• Rejected the Sophists' skepticism about acquiring knowledge.
• He believed in unchanging and universal truths graspable by human reason.
• He illustrated his case using the Allegory of the Cave and the Metaphor of the Divided Line in The Republic.

The Cave

• Imagine prisoners chained in a cave, able only to see shadows on the wall.
• The shadows are projections of objects and people passing behind them, in front of a fire.
• Prisoners perceive shadows as reality.
• If a prisoner is released and forced to turn around, the light would be painful, and the objects less meaningful than the shadows.
• Initially, the released prisoner would want to return to the familiar shadows.
• If dragged out of the cave into sunlight, the prisoner would be blinded at first, gradually adjusting to see shadows, reflections, and then real objects.
• Eventually, the prisoner would understand that the sun is the source of visibility and life.
• The liberated prisoner would pity those still in the cave, recognizing their ignorance.
• Returning to the cave, the former prisoner would struggle to see shadows and be ridiculed by the others.
• The other prisoners would resist any attempt to free them, even to the point of killing the liberator.
• The allegory suggests that most people dwell in the darkness of the cave, mistaking shadows for reality.
• Education is leading people out of the cave into the light.
• Knowledge requires an organ capable of receiving it, like vision.
• Education involves a complete turning away from the deceptive world of change and appetite.
• Conversion of the soul means ensuring it looks in the right direction.
• Rulers must compel people to ascend from darkness to light and, after liberation, return to the cave to help others.
• Plato argued for two worlds: the dark world of the cave and the bright world of light.
• Knowledge is based on what is most real and is virtually infallible.
• The Sophists were skeptical due to the variety of change, which depends on each person.
• Plato believed we could discover the objects behind the shadows and attain true knowledge.

The Divided Line

• The Divided Line provides more detail about the levels of knowledge.

• Four stages of development exist in discovering true knowledge.

• Each stage correlates the kind of object presented and the type of thought it makes possible.

• Moving through the line represents intellectual enlightenment from darkness to light.

  \begin{array}{c|c}
  \text{Types of Objects} & \text{Types of Thought} \
  \hline
  \text{The Good, Forms} & \text{Intelligence} \
  \text{Intelligible World} & \text{Knowledge} \
  \hline
  \text{Mathematical Objects} & \text{Thinking} \
  \hline
  \text{Visible World} & \text{Opinion} \
  \hline
  \text{Things} & \text{Belief} \
  \hline
  \text{Images} & \text{Imagining}
  \end{array}

• The line is divided into two unequal parts: the intelligible world (larger, upper) and the visible world (smaller, lower).

• This symbolizes the lower degree of reality and truth in the visible world.

• Each part is subdivided in the same proportion, representing clearer and more certain thought.

• Going from x to y represents continuous intellectual enlightenment.

• Objects represent different ways of looking at the same object, not different kinds of real objects.

Imagining

• The most superficial form of mental activity.
• Confronting images, the least amount of reality.
• Sense experience of appearances taken as true reality.
• An example is a shadow mistaken for something real, where one doesn't know that it's a shadow.
• The prisoners in the cave were trapped in ignorance because they were unaware they were seeing shadows.
• Deceptive images are also fashioned by artists and poets, which are at least two steps removed from true reality.
• Three levels of reality are:
  • The Form of Humanness.
  • The embodiment of this Form in Socrates.
  • The image of Socrates as represented on canvas.
• Criticism of art is that it produces illusory ideas in the observer.
• Poetry and rhetoric are serious sources of illusion because words create images in our minds.
• Plato was critical of the Sophists, whose influence came from their skill in using words.

Belief

• Induced by seeing actual objects.
• Seeing constitutes only believing because visible objects depend on their context for many characteristics.
• There is a degree of certainty, but it is not absolute certainty.
• Even if based on seeing, belief is still in the stage of opinion.
• The state of mind produced by visible objects is higher than imagining because it is based on a higher form of reality.
• Actual things possess greater reality than shadows but do not give us all the knowledge that we want to have about them.
• We experience these properties of things under particular circumstances limiting our knowledge.
• True scientists do not confine their understanding to particular cases but instead look for principles behind the behavior of things.

Thinking

• Moving from believing to thinking means moving from the visible world to the intelligible world and from opinion to knowledge.
• Thinking is characteristic of the scientist.
• Scientists deal with visible things as symbols of a reality that can be thought but not seen.
• Mathematicians engage in abstraction, drawing out from the visible thing what that thing symbolizes.
• They distinguish between the visible and the intelligible triangle.
• Science provides a bridge from the visible to the intelligible world.
• Science requires that we