Metaphysics: Guide
Nick Zangwill
For second years
The Lecture Plan:
In the 1st week, the topic was free will, with a brief introduction to
metaphysics first of all.
The 2nd week topic was colour (the topic for the essay).
In the 3rd week, there was a gap ¾
no lectures.
The 4th week topic was modality.
The three lectures of 5th and 6th week were devoted to truth.
Booknotes:
The textbook by Michael Jubien's Metaphysics (Blackwell 1997). It
is in the bookshop. Go buy!
By the way, an excellent philosophy dictionary is by Simon Blackburn, and
it is the Oxford Dictionary of Philosophy (1994). It is quite amusing in
places, and fun to browse in, following entries from one to the other. The Cambridge
Dictionary of Philosophy (1995), edited by Robert Audi is also very good;
it is more in-depth than
I'll now run through the topics. (You can skip forward from this menu.)
(The notes on each topic become
progressively fuller.)
Introduction: Metaphysics in General
Basic reading:
You should read 1.1 of the textbook carefully; and then the rest of the
chapter more quickly. Don't get bogged down in anything you don't understand.
Move on.
Here is a brief summary of the beginning
of my first lecture where I introduced metaphysics
Metaphysics is about what there is ¾
about what the world is like. It asks: what is freedom? What is colour? What is
necessity? What is truth? I suggested that science cannot answer all such
metaphysical questions because science itself makes metaphysical assumptions
about what the world is like. In the textbook, Jubien talks of 'analysing
concepts' as if this was a way of doing metaphysics. By contrast, I claimed
that we have a kind of 'folk metaphysics' that our concepts or language
presupposes. Analysing concepts may reveal our folk metaphysics. But folk
metaphysics can in principle be wrong. The world may not be the way we assume
it to be in our thought and talk. Concepts may be misleading. That is what some
think about freedom, colour and necessity. On the other hand, folk metaphysics
may be correct. It may truly represent what there is and what the world is
like.
Basic reading:
Read the textbook, chapter 7.
(Section 7.1 is quite heavy going on causation and laws. And section 3 is
on fatalism, which is less central. Skim those sections, but turn your brain up
full for 7.2.)
A very very basic quick introduction to the issue of free will (at
sub-ordinary level) can be found in the chapter "Free Will" of Thomas
Nagel’s What Does it all Mean? (
Supplementary reading:
You could try the notes on Jubien on free will on the web by Tomis
Kapitan who works at
Gary Watson (ed.), Free Will (
Issues:
Do we have free will? Are we determined? Can we be both free and
determined?
Here is a brief summary of my lectures
on free will.
1. I first introduced the ideas of freedom and then determinism. Students
should have a good grasp of what is involved in these ideas. I distinguished
fatalism from determinism. And I argued that quantum mechanics was irrelevant
to the free will issue.
2. I then introduced the idea of compatibilism. Students should be able
to state what this is and exactly how it seems to resolve the original problem.
(The compatibilist has a special conception of free action ¾ very roughly, an action caused in the right
way, by the persons beliefs and desires.)
3. Van Inwagen’s argument against compatibilism was considered next.
(Very roughly, the idea is that the state of the world 1000 years ago plus the
laws of nature determines what I do, so I couldn’t have done otherwise). Reply
(a) involved subtleties with "I could have done otherwise, if I had
chosen otherwise". Reply (b) involved denying the ‘could have done
otherwise’ principle (Daniel Dennett makes this move).
4. Lastly, I looked at problems of detail with compatibilism. (a)
hypnosis (b) brainwashing (c) psychosis. What’s the difference between them and
us? If there is no principled difference, the compatibilist has a problem. But
maybe there is some principled difference. If so, what is it?
This is the topic for the essay.
Basic reading:
Read chapter 6 of the textbook.
The Encyclopaedia of Philosophy (ed. Edward Craig) has a 3-page
entry on colour, which might be useful.
Supplementary reading:
Alex Byrne and David Hilbert,
The Stanford Encyclopaedia of Philosophy on the internet has a useful survey article on colour by Barry Maund at http://plato.stanford.edu/entries/color/
Issues:
What are colours? Are they real, or creatures of our minds?
We will look at three theories: (1) subjectivism (or 'dispositionism'),
(2) objectivism (or ' realism'), and (3) illusionism. (I'll only briefly
mention Jubien's own theory, 'independent ambiguism'.)
Here is a brief summary of my lectures
on colour.
(1) Subjectivism/dispositionalism. First I stated the theory. The
idea, roughly, is that colour is a dispositional relation to subjective
experiences. Redness is a disposition to produce perceptual experiences of a
certain character. In favour of the theory was the fact that we can imagine a
radical divergence between two sets of colour experiences, and we would have no
basis for condemning one set of experiences as mistaken. On the other hand, the
problems for subjectivism were: (a) the fact that we talk of colour in
non-relational terms (unlike 'to the left of'); (b) circularity ¾ 'green is the disposition to produce
experience of greeness'. This connects with the 'intentional
directedness' of our experiences of colour ¾ the fact that colours are the objects of our experiences; and
(c) potential counter-examples ¾
photographic paper, the shy chameleon, and killer-yellow.
(2) Objectivism/realism. The idea is that colours are intrinsic,
mind-independent properties of physical things. (a) Common-sense (folk
metaphysics) seems to support this view. (Our colour language is
non-relational.) Also, (b) it is common sense that we can be wrong about
colour. We distinguish real and apparent colours. These two points suggest that
we conceive of colours as objective. However, there is then a question about
how objective colour properties relate to physical properties. Can colour be
reduced to a physical property? There seems to be no property of surfaces that
all red things share. But perhaps the surface texture of an object plays the role
of reflecting light in a certain band, which could have been played by another
surface property. However, there are still problems about the possibility of
radically divergent experiences of colour, together with our tolerance of this
divergence. That seems not to be compatible with thinking of colour as a
mind-independent objective property.
(Jubien's Independent Ambiguism. He thinks that the concept of
colour is ambiguous between the subjective and objective concepts. But this
does not evade the circularity objection, and the directedness of our
experience of colour, which afflicts subjectivism.)
(3) Illusionism. On this view, there are no colour properties. And
science cannot be reconciled with common sense. The illusionist agrees with the
objectivist about the content of colour experiences. They purport to represent
objective properties. That's our folk metaphysics. But this folk metaphysics is
false. Nothing corresponds to colour as we represent it. This revisionary view
is made plausible if we think that objectivism (and not subjectivism) is
correct as an account of our experience, and we also think that the divergence
points means that there can be no such objective properties. Together, those
points encourage illusionism.
Basic reading:
Read chapter 8 of the textbook. (Don't worry too much about 'problem
(2)', pp. 137-38, or section (ii) (pp. 139-40.)
Supplementary reading:
The entries in the Encyclopaedia of Philosophy (ed. Edward Craig)
are very good. Check the entries on 'essentialism', 'necessary truth and
convention', and 'possible worlds'.
You could try the notes on Jubien on modality on the web by Tomis
Kapitan: http://sun.soci.niu.edu/~phildept/Kapitan/Jubmod.html
Perhaps try Michael Loux (ed.), The
Possible and the Actual, Cornell, 1979.
Or David Lewis, On the Plurality of
Worlds, Blackwell, 1986.
A recent article I found very interesting is Nicholas Rescher, "How
Many Possible Worlds Are There", Philosophy and Phenomenological Research,
June, 1999.
Issues:
How should we understand possibility and necessity? Are there real
possible worlds? Or is there a way of understanding possibility and necessity
without possible worlds?
We will look at three theories: (1) the possible world theory of David
Lewis; (2) abstract worlds; and (3) the more Aristotelian alternative that
Jubien and others favour. We will concentrate on (1), looking only briefly at
(2) and (3).
Here is a brief summary of my lectures
on modality.
(1) I began by introducing our everyday ideas of necessity, possibility
and contingency. The notions can be explained in terms of each other. (E.g.
Necessarily p = not possibly not p.) I gave examples of
necessary, possible and contingent truths. (You should be able to give examples.)
I distinguished different kinds of possibility ¾ physical possibility should be distinguished from metaphysical
possibility, and epistemic possibility is something different again.
Physical possibility is what is possible given the laws of nature, whereas
epistemic possibility is what is possible given our knowledge. "That
parcel might explode." (Although I didn't mention this in the lectures,
logical or conceptual possibility is probably best seen as a combination of
metaphysical and epistemic possibility ¾
but don't worry about that.) Metaphysical possibility is what we are most
interested in.
(2) There is the related idea that things have essential properties.
Gascoigne could have been a philosopher but he could not have been a fish. You
are essentially the children of your parents; you could not have sprung from
the genetic material of different parents. Whales are essential mammals. (For
sophisticates ¾ even if there is
more to being an essential property than being a property that a thing has necessarily,
an essential property at least implies some such necessary property.)
(3) We can translate modal talk into talk about possible worlds.
Necessary truth is truth in all possible worlds. Contingent truth is truth in
the actual world. Possible truth is truth is some possible world.
(4) David Lewis takes such talk literally. He thinks that there really
are possible worlds other than the actual world, and they are no less real.
These worlds are spatio-temporal wholes. The worlds are 'concrete'. But each
world is isolated from the others. They stand in no spatial, temporal or causal
relation to each other. So there are purple cows and unicorns, but none of them
are our 'world mates'. "Actual" is like "now" ¾ non-present times are as real as the
present, just as other worlds exist just as the actual world exists. I selected
five problems with this theory.
(a) The Humphrey objection. (This is Jubien's
first objection.) If we say "Humphrey might have won" surely we are
surely talking about him and not about someone like him in another possible
world. One reply (on Lewis' behalf) says that we are saying of Humphrey that he
stands in a certain relation to an other-worldly person. But this is
implausible. The modal property (that he might have won) doesn't seem like such
a relation.
(b) The relevance objection. (This is Jubien's
third objection.) Even if there are all the spatio-temporally unconnected
worlds that Lewis says there are, why would they be the truth-makers of modal
claims? They would seem like just more actual objects.
(c) The extravagance objection. It's
metaphysically extravagant to postulate an infinite number of worlds beyond the
actual world. (Lewis replies that it's not, or not in any naughty sense.)
(d) The 'primitive thisness' objection. Surely
worlds cannot be individuated in purely qualitative or general terms. Could
there be two qualitatively indiscernible worlds? Two new pins have different
relational properties. But this is not true of worlds. There must be something
that it is to be one world rather than another.
(e) The epistemological objection. How can we
have access to worlds that stand in no spatial, temporal or causal relation to
the actual world? There is also an access problem with mathematics, but that
doesn't seem to help much.
(5) Some philosophers take possible worlds to be abstract objects, like
propositions, or linguistic entities like sentences. Both these views are
implausible. (One objection is that the actual world is a possible world, but
it is not an abstract object or a linguistic object.)
(6) 'Primitivist' views remain. Jubien's 'property theory' may be a
theory of this sort. He explains modality as a relation between properties. But
it is also true that individuals can also have essences. On Aristotle's view,
modality and essence are primitive, basic and unanalysable notions. Every thing
and every property of every thing has essential properties. There is no
non-modal reality in terms of which we could explain modality. So the attempt
to explain what modality is in other terms is a mistake.
Basic reading:
Read chapter 5 of the textbook.
Supplementary reading:
Alvin Goldman's Knowledge in a Social
World (
R. Kirkham, Theories of Truth, MIT
Press 1992.
William Alston, A Realist Theory of
Truth, Cornell, 1996.
Issues:
What is truth? Is it a relation between our beliefs and the world? Is
truth epistemic? Is truth ‘relative’? Is it merely a device for ‘disquotation’?.
We will look at (1) the correspondence theory (Jubien calls these
'metaphysical' theories); (2) epistemic theories, including coherence theories
(these would be one variety of what Jubien calls 'epistemic' theories); (3) the
pragmaticist theory; (4) the relativist theory; and lastly (5) the
disquotational theory (which Jubien doesn't discuss).
Here is a brief summary of my lectures
on truth
(a) What is truth? If we try to 'analyse the concept' of truth, we are
doing 'folk metaphysics ¾
revealing our assumptions about what sort of property truth is. But that folk
theory might be false. (Some have held that the paradox of the Cretan liar, who
said "all Cretans are liars", shows this.) And perhaps in common
sense we do not think of truth as a real property. Perhaps talking of truth has
some other point. But let us start off investigating the idea that truth is
some kind of property.
(b) I think the issue of what the 'bearers' of truth are is important,
although most people you will read on truth pay little attention to the issue.
Jubien goes with 'propositions'. They are alleged to be what we are
thinking about ¾ abstract
objects, like numbers, outside space and time, with no causal powers. They are
supposed to be entities like That Grass Is Green. (Quine refers to propositions
as 'creatures of darkness'.) Anyhow, lots philosophers of language seem to
believe in them, even though I would have thought that it is more plausible
that we are thinking about snow or grass, rather than abstract objects. Rivals,
as truth bearers, are utterances of sentences, sentence types, and beliefs. My
view is that beliefs are the primary truth-bearers. (Can we say "What I
desire is true" ¾ we should
be able to, on the proposition theory?) And I think that sentences or utterances
are only true in as far as they express beliefs. Jubien and many others who
think that proposition are truth-bearers think that there were propositions and
truths before there was intelligent life, but those who think that sentences or
beliefs are truth-bearers think that there were no truths back then since there
were no truth-bearers.
1. The correspondence theory. On this theory truth is a relation
between truth-bearers and truth-makers. Truth is a relation between the mind
and the world. As Alvin Goldman points out, this theory links this use of
'true' to its use in 'true friend', 'true love', 'true to oneself', 'true to
the cause' etc. Truth is descriptive success, a faithfulness of the
truth-bearer to reality. A crucial point about this theory is that the world makes
beliefs (or whatever) true. Truth depends on the world. This issue will
keep recurring when thinking about this topic. It is a point about the direction
of explanation. A sentence/belief/proposition is true because of how
the world is, not vice versa. As we shall see, only the correspondence
theory respects this fundamental and intuitive point. Objections to the theory
worry about the correspondence relation and also about what facts are. I shall
just look at the latter. Objectors complain: What are facts? Are there facts
for each true proposition? Are there negative or disjunctive facts? Facts seem
to be as 'fine-grained' as sentences. Therefore facts are some kind of
projection from sentences. But this worry is baseless. (a) We should have a
'coarse-grained' theory of facts. One and the same fact can make different
sentences/beliefs/propositions true. For example the fact that John ran makes
it a fact that either John ran or Mary ran and that John did not sit, and thus
the fact that John ran can also make true the belief (sentence/proposition)
that John ran or Mary ran or the belief (sentence/proposition) that John did
not sit. (b) Facts are not just true sentences because facts can cause
things unlike true sentences. The fact that the government lost the war caused
the government to fall. The true sentence "the government lost the
war" didn't cause the government to fall. (c) Intuitively facts make
true sentences true. They explain why they are true. So the facts do not
just amount to true sentences.
2. The Epistemic theory of truth (including the coherence theory).
Intuitively there seems to be distinction between what is true and our evidence
or test for it. But epistemic theorists reject this contrast. They think that
truth somehow consists in our evidence or justification for thinking something.
(Note on terminology: Jubien uses the jargon 'epistemic theory of truth' to
refer to both correspondence theories that have beliefs as
truth-bearers (as opposed to propositions) as well as views that think
that truth is somehow a matter of justification. Along with most others,
I use 'epistemic theory of truth' only for the latter view.) However
(objection), it seems that there can be justified false beliefs; and there can
be truths that we don't know (about distant galaxies, for example). The
epistemic theorist can then complicate their theory by saying that truth is
what we would converge on in the ideal limit of inquiry. So truth
does not consist in our actual justification but in the fact that we would
be justified in certain circumstances. However (objection 1), surely truth
often outruns what we can know. Moreover (objection 2), the direction of
explanation is wrong. Where we converge in our beliefs it is (often) because
we are on to the truth, not vice versa. The coherence theory is a certain kind
of epistemic theory. On this theory, the truth of a belief
(sentence/proposition) consists in its coherence with other beliefs. But
(objection 1) would a well-written coherent novel be true? Objection 2: There
might be two different systems of beliefs that conflict even though they are
internally consistent. They cannot both be true. Objection 3: What exactly is
'coherence'? It is usually explicated in terms of consistency or entailment;
those ideas presuppose the notion of truth.
3. The pragmatist theory of truth. On this theory, a belief is
true when it is useful to believe it. But (objection 1) false beliefs can be
useful and true beliefs can lead to disaster. Also (objection 2) the direction
of explanation is wrong: certain beliefs are useful because they are
true. Truth explains usefulness, it is not the same thing as usefulness.
4. The relativist theory of truth. On this theory, something is
always true-from-some-perspective. (E.g. true-for-a-person or
true-for-a-culture.) So there is no 'absolute' truth. Well, some truths are
'relative' such as the truth of indexical beliefs (those involving 'I',
'here' or 'now'). And in some societies, belching is polite. But not all claims
are of this sort. Global relativism about all truth courts self-defeat. Is the
claim of relativism itself absolutely truth or only true from some perspective?
5. The redundancy/disquotational theory of truth. This theory
denies that 'true' ascribes a real property in the way that the other theories
assume. (In this it is parallel to emotivism or expressivism about
"good".) In fact most uses of the word 'true', they say, can be
eliminated. Instead of saying "'Snow is white' is true" we can just
say "Snow is white". The positive account is that the word 'true' is
useful when we want to say things like "The last thing Einstein said was
true" or "Everything the Pope says is true". But that does not
require that "true" refers to a property. The meaning of
"true", they say, is given us by 'Equivalence Principles' such as
"Snow is white" is true if and only if snow is white. (Watch out
to get the quote marks in the right place!) But (objection 1) what about
indexicals? Is your sentence "I am hungry" true if and only if
I am hungry? Some refinement, at least, is needed. Objection 2: The fact
that we can get by without a word does not show that it doesn't pick out a
property. Instead of saying that Michael is a bachelor we could say that he is
male and unmarried. But being a bachelor is a real property of him. He is a
bachelor in virtue of being male and unmarried just as something is true in
virtue of having a certain content and the world being a certain way. The fact
that we can often (but not always) eliminate the word "true" is neutral
between correspondence and disquotational theories. Objection 3: What exactly
do the Equivalence Principles say? If the "if and only if" is very
weak, it will allow in "Snow is white" is true if and only if grass
is green. But if it is taken to be necessarily true or an equation of meaning
then the right hand side will not entail (or necessitate) the left hand side.
That snow is white has nothing to do with any belief, sentence or proposition.
(Perhaps the necessitation only flows from left to right.) Objection 4: Suppose
we amend the so-called Equivalence Principles to get round the above problems: necessarily
if the sentence "snow is white" is true then snow is white. There
is then an issue about why such principles are true.
Redundancy/disquotational theorists take the principles as given, whereas
correspondence theorists can explain their truth. The truth-bearer "Snow
is white" is made true by the fact that snow is white. Truth here
is a real property (a relational property) that is determined by a truth-bearer
having a certain content and the world being a certain way, just as the
relation taller-than which holds between me and you is determined by my
being 6 foot tall and your being 5 foot tall. So the Equivalence Principles are
explained and not taken as basic and unexplainable.
And that was the end of my impartial and even-handed lectures on truth!