Introduction to Metaphysics and Epistemology
Besides introducing epistemology and metaphysics, I'm going to be using
these lectures as an excuse to talk about three of the most important people
who were instrumental in getting Western philosophy started. They are:
Socrates (470-399 BCE)
Plato (427-347 BCE)
Aristotle (384-322 BCE)
I will also be mentioning some other figures along the way.
I. Introduction to Epistemology
A. epistemology = df. the philosophical study
of knowledge, from the greek episteme, meaning "knowledge" or "scientific
understanding", and -ology," study of".
B. Important questions:
1. What is knowledge?
2. How much knowledge is possible? Can we have
- Is knowledge more than just correct belief?
- If yes, then what?
- How strong does the justification of belief
need to be in order for it to be knowledge?
- Does knowledge require certainty?
3. What kinds of knowledge are there?
- skepticism = the denial that knowledge
- There are both general and particular forms of skepticism
- general skepticism = no knowledge is within our reach (about
- Particular forms of skepticism deny that we can attain knowledge
about some specific area. E.g., a "moral skeptic" is someone who denies that
we can have knowledge about morality
- The attempt to overcome skepticism (in its various
guises) is one of the recurrent themes in philosophy.
- Socrates suggested that he might be the wisest
person in Greece because he alone was aware of his own ignorance. While he
wasn't a complete skeptic, he was quite modest in what he thought he knew,
which is typical of philosophical thinking.
One very important distinction:
4. Can we have any non-trivial a priori
- a priori knowledge
= knowable through pure, unaided reason or "just by thinking about it" (Example:
My knowledge that "Either it is snowing or it is not snowing." -- I don't
need to "go check".)
- a posteriori knowledge
= knowable only by having certain particular experiences, particularly sense
experiences. (Example: my knowledge that "It is not snowing.") (Also called
5. How reliable are the senses? Can we really gain knowledge through
- Most examples of a priori knowledge are trivial (e.g., the
snowing example, or things like "If I'm 26 years old, then I'm 26 years old.")
- Immanuel Kant (1724-1804) believed that the nature of space and time
(i.e. that time is linear and that space has three dimensions) is known
a priori, as are the truths of ethics (i.e. that it is wrong to commit
- Most philosophers believe that mathematics can be known a priori.
6. Which is our primary or fundamental source of knowledge?
- Problems revolving hallucination, optical illusions, etc. cast doubt
on the trustworthiness of our senses.
- More radical doubts stem from considering dreaming and/or the possibility
of being a "brain in a vat". How do we know that everything we see, hear
and feel isn't some sort of illusion or dream?
- David Hume (1711-1776): Just because we have observed things as being
a certain way, does that mean they always will be? Do we know the sun
will rise tomorrow? (Insert chalk-breaking example here.)
7. As humans, how do we "represent" the world? (These questions can also
be considered metaphysical.)
- rationalism: the theory that the fundamental source of knowledge
is pure reason or unaided thought (or that most knowledge is a priori
). Plato was a rationalist.
- empiricism: the theory that the fundamental source of knowledge
is sense experience (or that most knowledge is a posteriori). Like
most scientists, Aristotle was an empiricist.
- in the history of philosophy, almost no philosopher has been either
a complete rationalist or a complete empiricist; virtually
all agree that both sources of knowledge are important. The terms are usually
applied to a philosopher depending on which source is stressed in
his or her philosophy.
- How do our perceptions and ideas relate to what's "out there"?
- What does it mean to say that a belief we have is true?
- What does it mean to say our perceptions are accurate?
II. Introduction to Metaphysics
A. metaphysics = df. the attempt to answer the most fundamental
questions about the nature of reality, from the Latin, Metaphysica
, which literally means "After the Physics", referring to a book of
Aristotle's that was put immediately after the Physics in an early
Latin compilation of Aristotle's writings
B. Closely connected with ontology = the philosophical study of
being/existence, from the Greek ousia, meaning "being", and -ology,
C. Important questions:
1. What is existence? What is being? What is reality? (These are a little
too broad to try to answer directly.)
2. What is the basic vocabulary to use when describing what exists?
3. What are the basic kinds of substances?
- One model comes from Aristotle
- basic distinction is between substances and attributes
(and perhaps activities)
- A substance is an independently existing thing. Substances
have attributes. The table is a substance. Its color is an attribute.
The color is not itself a substance, because it cannot exist without the
- Two components of a substance: existence and essence.
The existence of the table is that it is. The essence of table is
what it is (a table).
- Two kinds of attributes: essential attributes and accidental
attributes ("accidents"). The table's essential properties are those without
which it could not be the same thing. The table could not be a table without
a flat surface at the top. The table could still be a table without being
- Other philosophers have developed other ways of talking about exists.
- Some candidates: matter or physical substance
vs. minds or mental/spiritual substances (see below)
4. Do attributes (e.g. beauty) exist independently of the particular things
that have them?
5. What is a person? What sort of substance(s) are we?
- If yes, then how?
- If no, what is the relationship between the beauty of one thing and
the beauty of another?
- Plato's theory of the forms: There is a separate realm of existence
in which things like Beauty itself, Goodness itself, etc., exist. These things
are called forms. The actual physical flower is only beautiful insofar
as it tries to imitate or copy the form of Beauty. However, the beauty of
the flower is not Beauty itself. We cannot see Beauty itself. The
forms can only be known by reason.
6. What is God? Does God exist? How much of existence depends on God? (
- materialism/physicalism: people are only complex material
objects; what we call the "mind" is just certain physical processes taking
place in the physical brain.
- dualism: a person consists of two distinct substances: a material
body and an immaterial mind, spirit or soul, which are
capable of separate existence.
- idealism/immaterialism: people are only immaterial minds,
spirits or souls; the body and all other material objects are
just images in our minds and do not exist independently from minds.
7. What is free will? Does it exist?
8. What is a law of nature? What is causation?
9. What is the nature of space and time?
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