Aristotle

Some Facts about Aristotle Lived from 384-322 Plato’s best student at the Academy Father was a physician—presumably taught

Aristotle to examine the natural world for the causes of things

Tutor to the young Alexander the Great Founded the Lyceum in Athens in 334 Followers called “Peripatetics” for the peripatoi,

or covered walkways (colonnades) in the Lyceum, where they would stroll and philosophize.

Some differences between Plato and Aristotle For Plato, true knowledge does not rely

on the senses For Aristotle, knowledge begins with

sense perception Aristotle is an early empiricist

Some differences between Plato and Aristotle Plato focuses on mathematics as a

way to guide people into thinking about philosophy

Aristotle focuses on biology and physics Observation, not theory, is the starting point for Aristotle

Some differences between Plato and Aristotle For Plato, the Forms are separately,

transcendently existing realities For Aristotle, forms they do not have a

separate existence beyond inhering in specific material things

Aristotle’s revision of Plato For Plato the ever-changing phenomenal

world is separate from the true and eternal world of Forms A thing participates in its eternal Form

Aristotle suggests that the form is found “inside” the phenomena, the universals “inside” the particulars.

Aristotle’s revision of Plato Aristotle thought Plato’s separation of sensible

things and their forms to be nonsense. He called the form of something its essence,

that which gives shape, form or purpose to something

The opposite of essence he called matter Essence without matter is perfect, complete and

ideal, but has no substance or solidity (and certainly no independent existence

Matter without essence is formless stuff, not actual but pure potential

Essence “realizes” (makes real) matter.

Entelechy: Potentiality becomes Actuality Aristotle thought that things “participating” in the

Forms was insufficient to explain their existence How did they become what they are? Aristotle

believed that nature provided the answer An acorn becomes an oak over time, but has no choice

but to be an oak!(In other words, it cannot be a pine, or a birch) The potential to be an oak is in the acorn, and this potential is actualized when the acorn becomes an oak.

The essence, which exists potentially, of something is actualized in the thing’s matter.

This process of actualization or becoming is called entelechy

The Four Causes

(Okay, got all that?◦ (Good, because it gets better)

Aristotle believed that the entelechy of a thing could be explained in four ways

That is, there are four causes of a thing, or four answers to the question, why is a thing what it is?

1.  The material cause: what something is made of.

2.  The formal cause: the thing’s shape, form, or essence; its definition.

3. The efficient cause: the motion or energy that changes matter.

4.  The final cause: its reason, its purpose, the intention behind it.

The Four Causes

The material cause: the bronze

The formal cause: the shape of the statue the sculptor had in made

The efficient cause: the heat, the forge, the tools, the sculptor

The final cause: to decorate a temple or a palace, to venerate Zeus, to give people something to pray to

Statue of Zeus or Poseidon, Athens

The Soul

• Aristotle’s main work on the soul is De Anima (Latin for Par Psyche, “About the Soul”)• For Aristotle, the soul is the “first entelechy”

of the body, the force that moves it to fulfill its potential• The soul animates (gives life to), or realizes a

body

• Unlike Plato, Aristotle believed the soul and the body cannot exist separately from each other• Unlike Plato, Aristotle did NOT believe in the

soul’s immortality. When the body dies, the soul dies.

The Soul of a Human• Unlike Plato, Aristotle did not believe in a personal

or unique soul. All living things have different souls, but soul does not account for their differences.

• LIKE Plato, Aristotle believed in a three-part division of the soul. UNLIKE Plato, Aristotle’s divisions were functional:• The nutritive soul: The souls of all living things

(plants, animals, and humans) have this function in common. It is the driving force toward growth

• The sensitive soul: Only the souls of animals and humans have this in common. It is the ability to sense one’s surroundings and have feelings

• The rational soul: Only humans have this ability to think, reason, and gain abstract knowledge. Only humans can be logical, creative, and imaginative

Human Nature• For Plato, a human being is an immortal soul

trapped in matter, whose true nature is to be one with the Forms

• For Aristotle, a human being is a rational animal, that is, an animal that reasons

• For both, REASON is what separates humans from all living things.

• Functional argument: • It is the nature of a knife to cut (its final cause), it is

proper for a good knife to cut well• It is the nature of a fish to swim, and proper for a good

fish to swim well• Just so it is the nature of a human to reason,

and proper for a good human to reason well!