Lecture Notes
CHAPTER 1 - THE PHILOSOPHICAL ENTERPRISE
Section 1.1 - Explaining the Possibility of the Impossible: Philosophical Problems and Theories
1. Philosophical beliefs can be divided into three broad categories: metaphysics, epistemology, and ethics.
2. Our thoughts and action are influenced by our philosophical beliefs, as witnessed by people in other
cultures who do not share our philosophy.
3. Philosophical problems arise when it is realized that certain philosophical beliefs are inconsistent with one
another.
4. Philosophical theories attempt to solve philosophical problems by showing how it's possible (or why it's
impossible) for a certain concept to apply to something.
5. Necessary conditions are the conditions which must be met in order for a concept to apply. Sufficient
conditions are the conditions which, if met, ensure that the concept applies.
6. The Socratic and scientific methods: (1) Identify a problem or pose a question, (2) Propose a hypothesis, (3)
Derive a test implication, (4) Perform the test, (5) Accept or reject the hypothesis.
7. Philosophy differs from science in that it tries to explain the conditions under which concepts apply rather
than the conditions under which events occur. In other words, philosophy tries to explain the logical
relations among concepts rather than the causal relations among physical objects.
8. To understand the difference between philosophy and science, it is important to understand the difference
between logical and causal possibility. Something is logically impossible if and only if it violates a law of
logic. Something is physically impossible if and only if it violates a law of nature.
Section 1.2 – Evidence and Inference: Proving Your Point
1. To arrive at the truth we have to reason correctly. Logic is the study of correct reasoning. It doesn’t attempt
to determine how people in fact reason. Rather it attempts to determine how people should reason if they
want to avoid error and falsehood.
2. Arguments come in two basic varieties: deductive and inductive. Good deductive arguments are valid; the
truth of the premises guarantees the truth of the conclusion. Good inductive arguments are not valid ; the
truth of the premises, at best, only makes the conclusion possible.
3. Some valid argument forms: affirming the antecedent, denying the consequent, hypothetical syllogism,
disjunctive syllogism. Valid arguments with true premises are sound. Some invalid argument forms:
affirming the consequent, denying the antecedent.
4. An inductive argument that would establish its conclusion with a high degree of probability if its premises
were true is a strong argument. A strong inductive argument with true premises is a cogent argument.
5. Some potentially cogent inductive argument forms: enumerative induction, analogical induction,
hypothetical induction (inference to the best explanation).
6. Criteria of adequacy are used to identify the best explanations. The goodness of an explanation is
determined by the amount of understanding it produces, and the amount of understanding produced by an
explanation is determined by how well it systematizes and unifies our knowledge. The extent to which a
hypothesis systematizes and unifies our knowledge is measured by various criteria of adequacy such as:
consistency, both internal and external, simplicity, the number of assumptions made by a hypothesis; scope,
the amount of diverse phenomena explained by the hypothesis; conservatism, how well the hypothesis fits
with what we already know; and fruitfulness, the ability of a hypothesis to successfully predict novel
phenomena.
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Section 1.3 - The Laboratory of the Mind: Thought Experiments
1. Philosophical theories are tested by looking for counterexamples; that is, situations where the theory should
hold but doesn’t.
2. Aristotle defined a human being as a rational animal. This theory can be tested by considering its
implications. If true, it would seem to imply that infants are not human beings, for they are not rational.
The theory can be modified to deal with this counterexample by amending it to state that human beings are
animals that have the capacity to reason.
3. Thought experiments can confirm or confute philosophical theories. A confuting thought experiment (a
counterexample) has the logical structure of denying the consequent. A confirming thought experiment has
the logical structure of affirming the consequent.
4. The question “What is a person?” is a central issue in the abortion controversy, for only persons can be
murdered. Thus if fetuses are not persons, killing a fetus is not an act of murder. Some believe that persons
are biological human beings. Warren’s moral space traveler thought experiment provides an apparent
counterexample to this. As a result, it helps explain how moral abortions are possible.
5. Thought experiments are possible because our conceptual competence gives us the ability to determine
whether a concept applies, even in situations we have never before encountered.
6. Some thought experiments are better than others because they are more well-controlled; i.e., more specific.
7. Some theories are better than others because they better meet the criteria of adequacy, such as simplicity,
scope, conservatism and fruitfulness.
Thought Experiments
Warren’s Moral Space Traveler
(A counterexample to the claim that only humans are persons.)
The Impossibility of Aristotle’s Theory of Motion
(Galileo’s counterexample to Aristotle’s Theory of Motion)
Tooley’s Cat
(A counterexample to the claim that potential persons have the same rights as actual persons.
Thompson’s Diseased Musician
(A counterexample to the claim that it’s always wrong to kill innocent persons.)
Thought Probes
Platonic Humans
(Can human beings be defined as featherless bipeds?)
Non-Human Persons
(Can non-humans be persons?)
CHAPTER 2 - THE MIND-BODY PROBLEM
Section 2.1 - The Ghost in the Machine: Mind as Soul
1. Cartesian dualism maintains that mental states are states of an immaterial substance that interacts with the
body.
2. Descartes claims that he is not a physical thing on the grounds that it’s possible for him to exist and not
have a body.
3. Descartes also claims that he is a thinking thing on the grounds that it’s not possible for him to exist and not
be able to think.
4. Descartes claims that his mind cannot be a physical thing because physical things are divisible whereas
minds are indivisible.
5. Cartesian dualism cannot explain how the mind interacts with the body.
6. Epiphenomenalism claims that although minds cannot affect bodies, bodies can affect minds.
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7. Since Cartesian minds are non-physical, they cannot be sensed. And since they cannot be sensed, we cannot
know whether anyone else has a mind. Thus Cartesian dualism leads to the problem of other minds.
Section 2.2 - You are What You Eat: Mind as Body
4. Since the way we verify sentences about other people’s mental states is by observing their behavior, it follows
that what we mean when we say that someone is in a mental state is that they have a certain behavioral
disposition. Thus, logical behaviorism has it that mental states are behavioral dispositions.
5. Putnam’s super Spartans suggest that mental states are not behavioral dispositions because it is possible to be
in a mental state and not have any particular behavioral disposition.
6. Neurophysiological research suggests that mental states are identical to brain states.
7. If mental states are identical to brain states, they would be knowable from a third-person point of view. But
as Nagle’s bat thought experiment suggests, consciousness—what it’s like to be a certain sort of thing—is not
knowable from a third person point of view.
8. Lewis’s pained Martian and Searles’s brain replacement thought experiment suggest that having a brain is
not a necessary condition for having a mind.
Section 2.3 - I, Robot: Mind as Software
1. Functionalism maintains that mental states are functional states.
2. One version of functionalism known as “strong Artificial Intelligence” or “strong AI” claims that the mind is
to the brain as the software of a computer is to its hardware.
3. Lewis’s pained madman and Putnam’s inverted spectrum thought experiment suggests that one can be in a
mental state without being in any particular functional state.
4. Block’s Chinese nation thought experiment suggests that one can be in a functional state without being in a
mental state.
5. The Turing test suggests that if a computer can use language as well as a normal human, then it can think.
6. Searle’s Chinese room thought experiment suggests that knowing how to use language is not sufficient for
understanding it.
Thought Experiments
Descartes’s Mechanical Moron
(A set of reasons for believing that an intelligent machine cannot be constructed.)
Leibniz’s Mental Mill
(An imaginary walk through an intelligent machine designed to show that consciousness cannot be explained
mechanically.)
Ryle’s University Seeker
(A demonstration of a category mistake.)
The Perfect Pretender
(A counterexample to logical behaviorism’s claim that there’s nothing more to being in a mental state than having a
behavioral disposition.)
Putnam’s Super Spartans
(A counterexample to logical behaviorism’s claim that being in a mental state requires having a certain behavioral
disposition.)
Nagel’s Bat
(A counterexample to the claim that consciousness can be explained in physical terms.)
Lewis’s Pained Martian
(A counterexample to the identity theory’s claim that being in a mental state requires having a brain.)
Putnam’s Conscious Computer
(Another counterexample to the identity theory’s claim that being in a mental state requires having a brain.)
Searle’s Brain Replacement
(A set of counterexamples to the claims that mental states are reducible to either behavioral dispositions or brain states.)
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Lewis’s Pained Madman
(A counterexample to functionalism’s claim that being in a mental state requires being in a certain functional state.)
Block’s Chinese Nation
(A counterexample to functionalism’s claim that there’s nothing more to being in a mental state than being in a certain
functional state.)
Putnam’s Inverted Spectrum
(Another counterexample to functionalism’s claim that being in a certain functional state is all that is needed for being in
a mental state.)
The Imitation Game
(The Turing test.)
Searle’s Chinese Room
(A counterexample to the Turing test.)
Block’s Conversational Jukebox
(Another counterexample to the Turing test.)
Your Mother, the Zombie
(A defense of behaviorism.)
Thought Probes
Living in the Matrix
(Could we be living inside a computer simulation of the sort portrayed in the movie, the Matrix?)
Animal Soul
(Do animals have souls?)
Bodies, Mind, and Death
(Have those in a permanent vegetative state ceased to exist?)
Mental Relay Stations
(Is the brain just a relay station?)
Speciesism
(Could you love an android?)
Neural Prostheses
(Would you have your brain cells replaced with computer chips?)
Computerized Resurrection
(Is Tipler right that we could be resurrected inside a computer?
Is Data a Person
(Is Data, the android in the Star Trek: Next Generation TV series, a person?)
Devout Robots
(If a robot that passed the Turing test asked to be baptized, should it be?)
Zombies
(Could a zombie (a creature with no mental states) do everything that a normal human being can do?)
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