nf0157: er okay er i'll just say a few things about the book er w-, as you know 
we've spent last term and the first part of this term talking about Locke and 
Berkeley er we're now moving on to Hume so the next six lectures er the last 
six lectures of this course are on Hume this is a copy of Hume's Treatise er 
i'll say a little bit more about that in a minute so that hopefully it will 
reach a larger audience when a few more people have got here er so i'm just 
going to say i'm going to say a few things about Hume and a few things about 
the Treatise er and then we'll start by looking at Hume's sort of philosophical 
method you might call it okay so Hume out of the three philosophers we study on 
this course Hume is probably the most famous of the three and he's certainly 
he's famous for his very very famous theories of cause and effect which we'll 
look at in a couple of weeks' time and 
for his influence on later philosophers particularly Kant who of course you're 
looking at in Modern Phil Texts er that is unless you're joint honours er 
handout er Hume of course follows on from Locke and Berkeley he's an empiricist 
like Locke and Berkeley like Locke and Berkeley he thinks that all of our 
interest and knowledge is derived from experience and we'll be talking much 
more about that today what that actually comes down to for Hume and he's also 
following on from the arguments from the kind of from the challenges that were 
laid down by Locke and Berkeley so he takes on a lot of Locke's er a lot of the 
the terminology used by Locke and Berkeley and he looks at another lot of the 
same kind of problems i mean particularly he's interested in abstraction and 
scepticism whether Locke and berk-, whether Locke's account in particular ap-, 
implies er scepticism about the ex-, external world whether empiricism implies 
scepticism about the external world and er the most i mean 
one of the most famous things that he takes on from Locke and Berkeley is is 
the theory of personal identity er he looks at Locke's account he looks at 
Berkeley's account and then he proposes his own account and we'll be looking at 
personal identity the very last lecture of this term in week ten er but i mean 
so those those are Hume's er some of Hume's philosophical antecedent why he's 
called an empiricist but i mean i think one of the another really huge 
influence on Hume which i talked about in the very first lecture of this course 
back at the beginning of last term with Newton er Hume's a scientist really he 
he's he's really taking a scientific method and applying it to philosophy so 
Newton offers us this this kind of mechanistic account of matter it's this this 
whole new science of matter in which all of the movements of of particles of 
bodies can be described in terms of equations so it's moving towards the kind 
of deterministic science that we really take for granted 
today the fact that if something happens in the world there will be a reason 
for it there'll be an explanation for it and Hume in i-, i mean this is really 
i suppose the the biggest shift in thinking in Hume is that Hume saw man as 
another part of the natural world i mean just another part of the natural world 
and and if you think well okay so what's so exciting about that i mean just 
think about how the rationalists say Descartes viewed viewed man in the 
rationalist picture of of human kind is of this sort of this being in the image 
of God someone who whose life is governed controlled purely by reason right so 
for the rationalists you know you're not a part of nature sort of swept along 
with everything else your reason governs your life you have control in virtue 
of being a rational animal right that's the rationalist picture but Hume 
completely turns that on its head i mean it's te-, in reason is the slave of 
the passions very famous 
quote from Hume reason is the slave of the passions so reason is is a sort of 
secondary thing the passions the emotions the feelings are what really govern 
us and not reason reason is something that comes in later and er i mean so 
basically what that means is that man humans are just another part of the 
natural world we can explain human behaviour in exactly the same kind of way as 
we explain things scientifically and then again i mean just as a sort of modern 
comparison i mean you might want to think about Searle that you did last year 
in part one i mean the sort of contrast between the kinds of exan-, 
explanations we offer of of human action and the kinds of explanations of 
scientific phenomena basically what Hume's saying is there's one kind of 
explanation that's applicable to all of these things i mean obviously the the 
things we're explaining are slightly different in in terms of humans in terms 
of of of human thought human action we're dealing with 
with maybe ideas or thoughts or whatever as opposed to physical objects but 
basically there's one kind of explanation and it's a naturalistic kind of 
explanation so that's the the the huge sort of shift in thinking that that we 
get in Hume and i mean Hume Hume sees this as a kind of an experimental enquiry 
so h-, he takes this empirical scientific method which Newton applied with such 
success but which goes right i mean you may remember the historical sort of 
picture i was giving you back at in at at the end of at the beginning of last 
term er th-, the sort of going right back to Bacon the sort of empiri-, the 
rise of empirical science and Hume's taken that picture and what he wants to 
derive is write some the science of man okay so Newton gave us this er when 
somebody starts writing this down you see this is Newton gave us the science of 
matter and Hume is giving us the science of man along exactly the same lines so 
he wants to come up with some kind of 
laws of association you know just like Newton has this equation you can draw 
the the fall of a billiard ball or whatever the the fall of a not a billiard 
ball things that you drop off towers and things you can measure their velocity 
in terms of the forces acting on it Hume thought a similar kind of account 
would be possible for the man the reason for what goes on in our our 
understanding er right okay how does he do this well how are we going to how 
are we going to empirically investigate the human mind well of course the 
methods of neuroscience the methods of of you know looking at medical methods 
looking at people's brains obviously weren't very far advanced and anyway maybe 
that's the wrong place to look i mean Hume's interested in thoughts and 
feelings and so on so really the method that we use is of course introspection 
we look into our own minds we see what's going on there and we can posit laws 
relations we can carry out this empirical investigation 
into all the whole nature of human understanding so this is the project well in 
the the next six lectures so today and and the rest of this course er we're 
going to look at various topics in Hume's philosophy and these taken from book 
one of Hume's Treatise of Human Nature so this is the Treatise it's a very fat 
book er however this this particular one is very fat because it contains a 
large amount of introductory material and er glossaries and notes and all this 
kind of stuff if you're going to buy the Treatise so this is a quick st-, step 
back from Hume for a second 'cause i wanted to say this at the beginning er if 
you want to buy a copy of this this is very very good value this is a tenner 
and it's quite can you see how thick it is that's quite a lot of book for a 
tenner if you given how expensive philosophy books are er this is edited by 
Norton and Norton er and it was on the reading list right at the start of term 
so you should have that already er there are ve-, er they 
should be available in the bookshop i haven't actually checked i did ask them 
to order some copies er there are lots of other editions of the Treatise so you 
don't have to get this one but this one's got a very big fat introduction so er 
it it might be useful er the Treatise in fact has has three books in it er and 
we're only going to be looking at book one book one is entitled Of the 
Understanding so this is Hume's the the beginning of hu-, Hume's science of man 
as it applies to to reason and to thought er we'll be look-, i-, it basically 
introduces this philosophical method and then it looks at applying that to a 
number of philosophical issues such as space and time causation knowledge and 
belief personal identity er the second book is is Of the Passions so that is an 
account of o-, o-, a a really i mean an account that was discredited for a 
while because of things like Freudian psychoanalysis and things like that but 
now is is is people looking at it more and it 
gives an account of the emotions the desires things like pride and lust and and 
and pity and and and of course human freedom which is probably one of the most 
important things in a in book two and then book three is is Hume's moral 
philosophy and i'm not sure i meant to ask Philip whether you do any hu-, of 
Hume's moral philosophy do you do any of Hume's moral philosophy in your morals 
course well even if you don't it's certainly something that people will refer 
to so the the moral philosophy is in book three of the Treatise but as i said 
we're only going to be looking at book one and we're going to look at number of 
topics from book one we're going to start by looking at Hume's philosophical 
method and then next week we'll talk about belief then two weeks on his theory 
of causation his scepticism and then finally his theory of personal identity 
that's the plan any questions about Hume in general cool right okay so what i 
want to do today is just i mean having 
sort of given you a little tiny tiny bit of an overview of what Hume's about er 
is just look at that he's basically his his tennets of his empiricism what his 
empiricism means for Hume how he sets it out what the basic principles he's 
working with are and these basic principles are vital because these are the 
principles that he later applies when he comes to look at specific problems so 
when he looks at causation he uses the principles we're going to look at today 
in order to analyse the notion of of cause so this is basically the the most 
important ground work the basic foundations of of Hume's empiricism and er this 
er basically comes down to his distinction between ideas and impressions and 
what he does with it so this is on the handout er c-, first talk about what the 
distinction is why it's important and what we might think about it okay right 
so er the very very very first thing Hume does in the Treatise after he's he's 
written the introduction is he starts 
talking about starts out this introspective enquiry by looking into the mind 
and seeing what he finds there and the first things he said is this is the 
first sentence of the Treatise all the perceptions of the human mind resolve 
themselves into two distinct kinds which i shall call impressions and ideas 
okay and then he talks about the difference between them and the first thing i 
want to draw your attention to is is his terminology now what did Locke call 
what was Locke's term for the contents of the human mind all the objects of 
perception 
sf0158: idea 
nf0157: idea right so Locke uses the term idea as this general term for the the 
objects of of the mind the things in the mind and Hume starts out by saying all 
the perceptions of the human mind resolve themselves into two distinct kinds 
which i'll call impressions and ideas and so Locke is imme-, er Hume's beg your 
pardon Hume is immediately laying down his terminology in a 
different way from Locke and in fact he has a footnote here and he says i here 
make use of these terms impression and idea in a sense different from what is 
usual and i hope this levity will be allowed me perhaps i rather restore the 
word idea to its original sense from which Mr Locke has perverted it in making 
it stand for all our perceptions so he's s-, started by having a go at Locke 
who's er used this term idea to stand for all of our perceptions but really 
perceptions is is Hume's term for idea so where's my pen so Locke's idea is 
basically what Hume calls perceptions now you may not think that's very helpful 
because of course perceptions thereby are going to include things like you know 
when i sit here and i imagine myself on that beach with all those men with six 
packs or whatever that is n-, that is actually a perception in my mind although 
as you can see i'm clearly not perceiving it more's the pity so er that's 
that's what 
Hume calls perceptions this is what Locke calls ideas and Hume defi-, divides 
perceptions into impressions and ideas and this distinction is extremely 
important and is the whole foundation for his empiricism which is why i'm 
banging on about it so much so what's the difference between impressions and 
ideas well h-, the next sentence says the difference betwixt these consist in 
the degrees of force and liveliness with which they strike upon the mind and 
make their way into thought and consciousness those perceptions which enter 
with most force and violence we may name impressions and under this name i 
comprehend all our sensations right so sensations things that we sense passions 
and emotions as they make their first appearance in the soul by ideas i mean 
the faint images of these in thinking and reasoning such as for instance are 
all the perceptions excited by the present discourse excepting only those which 
arise from the sight and touch et cetera so the distinction seems to be being 
made here in two ways on the one hand the distinction is is bet-, i-, with the 
degrees of force and liveliness with which they strike upon the soul so 
impressions are the more forceful and lively perceptions well we can talk about 
f-, what Hume exactly means by forceful and lively in a minute er but 
impressions are the more f-, forceful and lively ones and ideas are the faint 
copies of impressions so ideas are fo-, er impressions are forceful ideas are 
fainter and then Hume says under impressions i comprehend all our sensations 
passions and emotions so impressions are the ones that we get directly from the 
senses or directly from the emotions so there's an interesting sort of addition 
here that when we talk about mental objects we tend to be talking about er 
objects of perception or objects of propositional attitudes but in fact Hume's 
including here emotion so if you feel really angry you know someone pushes in 
front of you in the queue for the petrol station or something and you're 
sitting there going [growl] really angry and that is an impression right i mean 
there's noth-, there's not sort of an object of that in the sense there's not 
something angry that you're seeing that is an impression of angriness mean it's 
your anger is the impression so we enclose emotions in here as well as things 
you perceive ideas on the other hand are so what does Hume says er the faint 
image of these in thinking and reasoning so if you read a book and it's talking 
about Hume you may form an idea of Hume but er this is a a f-, a f-, this is 
not an impression you're not seeing Hume it's a it's a a fainter idea that's 
being used in thinking yeah namex 
sf0159: is is it then er reflections on emotions er 
nf0157: right exactly ideas are also going to include reflections on emotions 
so if 
you think back to a week ago when your friend said something really rude to you 
down the pub and you were really angry then you might remember that anger now 
okay you might think back to it and remember that you felt angry now it may be 
that you may also feel angry now but it may also be that you don't feel angry 
now you've you've got over it you've forgiven your friend but you remember the 
anger and so in that way the anger is is an idea it's a faint copy of the anger 
that you felt before but what i want to what i want to to draw out here is is i 
said there are two ways of making this distinction one is in terms of 
forcefulness okay so you've got the impressions of forceful and the ideas of 
the faint copies can everyone see the board sorry the lights are not on where 
is it okay that's better on the other hand impressions are to do with sensing 
or immediate perception as it were and ideas are to do 
with thinking or reflecting or maybe remembering or whatever and and th-, Hume 
wants to have both of these so i'm going to come back to whether this actually 
cuts the distinction in a minute okay th-, there are there are so there are two 
things that are going on in these first sort of basically three or four 
sentences of the Treatise that impressions are forceful and ideas are faint 
that impressions are to do with sensing and perceiving and that ideas are to do 
with later thinking or reflecting on things er and i mean of course your ideas 
you can you can read a book about say i don't know some place you've never been 
some exotic island you can read a book about it and get lots of ideas of it 
those are nonetheless still only going to be ideas because they're created by 
thought rather than created by sensation the question is can Hume maintain this 
forcefulness distinction in that way so i'm getting ahead of myself now i'm 
going to come back to that in a 
minute but is that basically clear yeah good right okay the second thing that 
Hume does that's that's very important which is in the n-, second paragraph of 
of the Treatise and this is the division in simple and complex perceptions i 
don't want to say a huge amount about this 'cause it's fairly obvious and we've 
also come across it in Locke already so in roughly the same way that Locke does 
er Hume distinguishes between simple and complex ideas but this has a big 
significance for him and what does he say about this he says well we can divide 
our perceptions into simple and complex simple perceptions or impressions and 
ideas are such as admit of no distinction nor separation okay complex ideas are 
contrary to these and may be distinguished into parts er so what does he mean 
by this well if you have a sensation er an idea or a sensation or whatever and 
you can't break it down into smaller parts then it's simple if you can 
break it down into parts then it's complex so what kind of things are going to 
be simple perceptions example 
sf0160: red 
nf0157: red good yes okay any others anyone want to 
sm0161: blue 
nf0157: blue yeah okay all right 
sf0162: 
nf0157: colour ones colour ones are going to do 
sm0163: rough 
nf0157: rough yeah okay that that's probably pretty simple yeah 
sf0164: secondary qualities 
nf0157: yeah pretty much all secondary qualities are going to count as simple 
perceptions the immediate feel the immediate but again this is controversial so 
we're going to come back to this later er complex perceptions what kind of 
complex perceptions are you having right now er actually no i don't want to 
know about some of them [laughter] but are there a-, any you want to share 
namex come on keeping me 
sm0165: 
nf0157: okay i mean look supposing i'm looking at 
sf0166: the table 
nf0157: the table okay the table is going to be a pretty complex perception 
because er it's got i mean i can physically divide it into it's got a colour 
it's got a a hardness it's got a 
sound if i bang on it there are there are b-, we can divide this up into a 
bunch of things and in fact that's the kind of example Hume gives if you're 
thinking of ord-, perceptions of ordinary physical objects they're going to be 
divisible into parts so he's got an apple says though a particular colour taste 
and smell are qualities all united together in this apple it is easy to 
perceive they're not the same but at least distinguishable from each other so 
we can distinguish in the perception of an apple the colour taste and smell i 
think they had better apples around when Hume was alive but anyway so one one 
can imagine that there are these these physical objects we can divide 
perceptions into parts right okay this may er ring a bell er in your your 
lectures on perception you may recall er talking about er phenomenalism logical 
positivism breaking er immediate objective perception down into the sense data 
that make them up so objects are constructions out of 
sense data does that ring any bells at all yeah okay well whatever okay so er 
we can divide we can divide complex perceptions into parts right this leads to 
a very very important principle that Hume formulates which is that if you have 
a simp-, w-, w-, okay s-, start at the beginning what's the relationship 
between our ideas and our impressions is it the case that every idea 
corresponds to an impression and every impression corresponds to an idea 
that's the question he then asks if you've got an idea does it have to corres-, 
is there does there have to be some impression to which it corresponds now if 
you see why this is important for the empiricism because of course recall that 
the impressions are the ones that are derived directly from the senses okay can 
anyone think of an example of an idea that might not be derived from an 
impression so are there ideas that you have that you haven't derived from 
impressions 
sf0167: an idea 
nf0157: sorry 
sf0167: is it God for example 
nf0157: 
God is difficult okay 
sf0167: 
nf0157: because i mean some people might think that you can actually have er 
direct experience of God 
sf0167: mm 
nf0157: okay you could perceive God er i mean i er people like Berkeley what 
Berkeley says about that is quite hard to to divine given his his theory of 
perception but i mean certainly around this time that was thought of as heresy 
so maybe God would would would count in this way but i mean is there a more 
ordinary example than God 
sf0168: is it the things like the unicorn again 
nf0157: right exactly i mean i-, you've got an idea of a unicorn if i say 
unicorn you form in your mind an idea of a thing with a looks like a horse but 
it's got a horn on the front of it have you ever had an impression of a unicorn 
no so you have an idea which doesn't correspond to an impression so Hume thinks 
of examples like this i mean his example in the Treatise is the New Jerusalem 
which is a biblical reference and it's th-, this fantastic mythical city where 
the 
streets are paved with gold and rubies or whatever you know and dadadadada one 
can have an i-, an idea of the New Jerusalem without ever having seen it or or 
a unicorn or whatever so there are but he also thinks that there are 
impressions of which you have no ideas as well and his example for that is a 
bit more bit more complicated i mean it's basically say i mean ho-, how many 
people here have been to Paris er quite a few now those of you who've been to 
Paris you have an impression of Paris i mean you were there you saw er okay but 
could you now unless you are anyone who actually lived there for a while can 
shut up for a minute but the rest of you did could you give your idea of Paris 
could you sort of give a a say a street plan of Paris or a sort of description 
of all the details of Paris well of course you can't because even if you saw 
those i mean even if you saw those details in the first place you're not now 
necessarily going to be able to produce them so the 
idea sort of may have been there originally but it's now faded away er and this 
is exactly the example that Hume gives he says i have excuse me i have seen 
Paris but shall i affirm i conform such an idea of that city as will perfectly 
represent all its streets and houses in their real and just proportions so 
sometimes we can have impressions with no ideas and sometimes we can have ideas 
with no impressions well okay so so that's where we've got to right now this 
isn't going to help this empiricism but Hume points out that all of these 
places where there isn't a correspondence a case is a complex of ideas and 
impressions right the unicorn is a complex idea you can separate out the parts 
you can separate out the horse and the horn yeah familiar example er could the 
same be true of simple ideas and simple impressions and this is basically the 
question for for the lecture today could there be a simple idea with no 
corresponding 
simple impression okay what do you reckon could there be a simple idea with no 
corresponding simple impression 
sf0169: what do you mean by simple idea i get the simple impression like 
colours and things 
nf0157: right 
sf0169: what would be a simple idea 
nf0157: well a simple idea would be i mean if you sh-, sort of r-, imagine now 
that particular shade of er blue that's Conservative Party blue right i mean 
it's not in front of you but you can imagine it so that's an idea of that 
colour i mean if if you remember what colour your carpet is at home or 
something like that so that's an idea of a a colour which isn't corresponding 
to a present impression or remembering a smell or remembering a taste or 
something like that so could we have a simple idea that having had the 
corresponding simple impression 
sf0170: i thought we couldn't 
nf0157: right 
sf0170: because er there is a th-, er example of the Mary the scientist 
nf0157: 
yes yes 
sf0170: who works hard in the laboratory 
nf0157: mm-hmm 
sf0170: she's very smart she but o-, everything in the laboratory is black and 
white 
nf0157: yes 
sf0170: and she knows everything every physical er theories about colours 
nf0157: mm-hmm 
sf0170: but then she if she if she's shown like s-, for example red she doesn't 
know which colour it is 
nf0157: right right and when she sees red she gets a new experience could she 
imagine red could Mary so this is Mary who's grown up in this cruel and 
entirely black and white environment could Mary have an idea of red if she's 
never seen it okay does anyone think you can have a simple idea without a 
corresponding impression right who thinks you can't right okay what about the 
rest of you 
sm0171: if it's er 
nf0157: not sure 
sm0171: i think you can make something up can't you 
sf0172: mm 
nf0157: mm-hmm 
sm0171: ridiculous things 
nf0157: right like what 
sm0171: er 
nf0157: the key question being are they simple or complex 
sm0171: yeah i'm trying to think of a simple one actually then you think 
nf0157: mm-hmm 
sm0171: complex thing like a book with no printing in it something like that 
that's a bit complex isn't it 
nf0157: right right and this is the problem that of course 
our imaginations are hugely powerful and we can think up lots of complex ideas 
of strange things that we've never actually seen question is could we think up 
a simple idea one that couldn't be further divided where we haven't had a 
corresponding impression 
sf0173: with the simple ideas don't we have to have experienced them in the 
first place to know what they are so therefore you have to 'cause of the 
secondary qualities 
nf0157: what 
sf0173: you always you have to experience it to understand it like if you're 
deaf even if someone i don't know explained writes down what sound is i mean 
nf0157: mm-hmm 
sf0173: you're never going to know 
nf0157: right i mean there's a there's a difference i think that's a that's a 
very good point and this is wh-, h-, an example that Hume uses in fact i mean 
the the question is it's it's not would would we know what to call it i mean i 
suppose in a a way it's not that Mary doesn't know what to call red that she 
sees wh-, she sees the different colours and she 
doesn't know their names because i mean that would be true if you just didn't 
know any colour words you know if you were in a foreign language and you didn't 
know what to call them something like that but it's just that when i mean so 
the example of Mary goes she sees red she's having an experience that she's 
never had before right that she couldn't have imagined that experience before 
she actually saw it all right well look i i i want you to think about this 
'cause this is a this is really quite important er i'm just going to go through 
what Hume says about these these er arguments er well no before i do that i 
mean i'll just say what the the the important principle is and this er the the 
the the basic the thing that Hume is is very very keen that Hume has to 
establish is that complex impressions and ideas there may be one without the 
other but basically at the level of simple impressions and simple ideas there 
is a one to one correspondence between simple impressions 
and simple ideas so if you've got a simple impression you've got a simple idea 
if you've got a simple idea the second one is much more important if you've got 
a simple idea you must have had that corresponding simple impression right why 
is that an important principle well basically this is what empiricism is for 
Hume so Hume's an empiricist he thinks all of our knowledge is derived from 
experience and the bottom line of this is that is this that what we might call 
a principle of significance that and this is this is famously expressed in his 
i-, i-, in-, Inquiry have i put this on my handout no i haven't ah well okay i 
mean if we if if we have er all our simple ideas are derived from simple 
impressions which are correspondent to them and which they exactly represent er 
there it is it is on the handout it's the third bullet point under the 
significance of Hume's distinction er if Hume's concern that philosophers 
particularly scholastic philosophers 
people talking about things like substance have no empirical foundation are 
just talking rubbish it's not just that they're sort of putting forward 
philosophical principles which we're not sure if they're true or not his basic 
this this this one to one correspondence between ideas and impressions is 
intended to guarantee that that in order for a word or a phrase or or something 
that we talk about to be significant to be meaningful there has it has to 
ultimately reduce down to impressions to things that we can have knowledge of 
in the abstract from the Treatise he offers this sarcastic remark so this is 
someone who's who's going through philosophical treatise he's looking through 
trying to figure out what's going on and i-, he says when he he being 
presumably Hume when he suspects that any philosophical term has no ideas 
annexed to it as is too common he always asks from what impression that 
pretended idea is derived and if no 
impression can be produced he cont-, he concludes that the term is altogether 
insignificant right so whenever you're looking at a philosophical concept a 
philosophical idea or some other thing that we might be talking about we say 
from what impression is that idea derived now if it's a complex idea there may 
be a complex impression to which it corresponds so for example a complex idea 
of say father bears an impression of a father so that's okay but if we're 
talking about something like substance right recall substance from from Locke 
from what impression is our idea of substance derived well maybe there's a 
complex idea of substance no can't find that maybe we can break it down into 
simple impressions which we've built up like with the case of the unicorn right 
we have the a complex idea of a unicorn we've built that up from simple ideas 
which are derived from simple impressions a simple idea of well more simple 
ideas of the horse and the horn or 
whatever with substance are there simple ideas which correspond to impressions 
from which our our idea of substance is derived and Hume says well no there 
aren't what does that mean about the philosophical term substance it means that 
this term is wholly insignificant right it's not just that there isn't any 
substance it's just that substance doesn't mean anything right so this term is 
not just doesn't apply to anything it's actually meaningless it's insignificant 
so this distinction between impressions and ideas guarantees Hume's empiricism 
it guarantees that all the terms we use at base have to refer back to something 
which we've observed 
and that's the important i mean of course it also er allows Hume to say things 
like he can he wants to be able to redu-, rene-, refute the principle of the 
arguments the doctrine of innate ideas er he thinks this will this will offer a 
foundation for the science of man and so on and so forth but the bottom line of 
this is from what impression is this pretended this supposed idea derived and 
if it isn't derived from simple impressions at bottom line then it's not really 
an idea it's not really something that you can have you may think you have an 
idea of substance but really you don't it's not really an idea at all that's 
the bottom line that's that's empiricism for Hume so whether or not you you you 
like this 
which we're going to come back to in a second this is this is a a highly 
significant doctrine that at the bottom line there is a there's the one to one 
correspondence between simple ideas simple impressions er simple impressions 
are all derived simple ideas are all derived from simple impressions and you 
couldn't have a simple idea without an i-, simple impression and we can build 
up more complex ideas from them but if you have an idea you've got to either 
have an impression that directly corresponds to it or you've got to be able to 
break it down into simple ideas which correspond to impressions and then and if 
you can't then it's it's not something that's significant or meaningful right 
sm0171: do you not get ideas in mathematics about any impressions 
nf0157: mathematics Hume didn't like very much he's things he says about 
mathematics are not really very helpful i mean it's it's difficult for 
empiricists to talk about abstract objects in maths i mean you know okay so i 
might have the idea of i don't know how 
many people are there in this room twenty-something whatever twenty-three i 
might do i have the idea of twenty-three because i can see twenty-three things 
or is twenty-three is the idea of twenty-three sort of some much more abstract 
thing but if so how could i ever have an impression of it i mean these are the 
kinds of questions that empiricists in in mathematics have to face but i mean 
the i mean i suppose one could sort of say that most mathematics is built up 
from kinds of basic principles to do with counting to do with systems of 
numbers of things or or properties of numbers whatever you call them and if you 
call them minus numbers then they're like positive numbers but with an extra 
operator on or something so so i mean there's there's a big question there 
about how far you can get if you're an empiricist philosopher of maths but you 
can get quite a long way but by just breaking things down to numbers which 
arguably you know okay i see three people sitting 
here so i have an an impression of three 
sm0171: is progress in science not almost always from ideas before we can have 
impressions 
nf0157: but the point is not that there could be ideas of which we've not had 
impressions i mean Hume's quite happy that we have an idea of a unicorn for 
example 
sm0171: mm 
nf0157: or of some huge scientific theory that we've postulated that's fine 
that's fine because we can break the unicorn down into simple ideas which do 
correspond to impressions and the same with your theory 
sm0171: it's not simple is it if if if you think that if something's scientific 
it's not like a simple idea is it 
nf0157: but we can break it down into simple ideas 
sm0171: mm 
nf0157: and those simple ideas must correspond to impressions 
sm0171: mm 
nf0157: because if they don't i mean it's not just that you know it's not just 
that they don't they don't correspond to impressions it's that we can't have 
those thoughts i mean if you take something like substance which which is one 
of the targets of of Hume's criticism here i mean remember what 
Locke said about substance he didn't think we had this clear idea of substance 
and we were just trying to sort of figure out exactly what its properties were 
we have a confused and and vague idea of substance right and Hume would say 
well the the reason that you have this confused and vague idea is is because 
it's not really an idea at all 
sf0174: what is it 
nf0157: well it's not anything i mean it's just it's a mistake i mean you think 
you've got you may think y-, do you think you ha-, i mean i don't know do do 
you think you've got an idea of substance 
sf0174: yes 
nf0157: u-huh 
sf0174: 
nf0157: well er in that case you shouldn't have i mean because [laughter] the 
things i mean it's like it's like having an idea of a round square i mean have 
you got an idea of a round square you can try and sort of think well i've got 
some kind of idea of it's like of a round square but 
sf0175: can you say that can you just an idea of er substance by abstraction 
nf0157: right and thi-, and and Hume has a lot to say about abstract ideas 
i mean he th-, basically takes ra-, Berkeley's view on abstract ideas he thinks 
of ideas as you can't have i mean remember Berkeley's criticism of Locke the 
abstract general idea of a triangle would have to have be both be all three of 
equilateral isoceles and scalene that's not possible and Hume follows that line 
he thinks abstract ideas are particulars particular ideas of which we notice 
certain things and so you couldn't have an idea of sub-, substance by 
abstraction because er it would just be not consistent so you know the idea 
that we think we've got of substance it's just not a possible idea it's like 
the idea of a round square 
sf0176: the idea so how do we get well what do we get it from if we have the 
idea i if the word appears in the language so 
nf0157: well i mean i mean this is the thing that we can we can invent words 
for things that are just in i mean if you think of er say an an aetheist's 
account of God they're going to say well God is a word sure but 
there isn't any such thing as God it's just something that people have decided 
to call but really it's not it's not something that's consistent or coherent or 
anything like that so when you actually come down to say what is this you you 
shouldn't you don't have an idea of God right okay er i just want to say two 
things about Hume's distinction er i said i'd come back to this distinction now 
first thing to say about this distinction is Hume wants to make this 
distinction he it's important for his empiricism that impressions are the 
things that we get through perception or through a perception in the sort of 
extended sense that it includes emotions that it includes immediate emotional 
feelings but he makes the distinction officially in terms of forcefulness and 
liveliness so the impressions are the forceful perceptions and the ideas are 
the faint copies now does that seem a good way to make the distinction so 
forget about can if if we take the top one as 
the official definition does it correspond to forceful ones are the ones you 
sense and the less forceful ones are the ones you reflect on so could you 
sometimes reflect on something that was more forceful than something you're 
seeing yeah yeah okay exam-, can we er can you think of an example 
sf0177: can it like if you perceive something that was had a bit impact on you 
nf0157: right 
sf0177: so you would you would think about that in more with more impact than 
if you just kind of you know remembering some old man crossing the road and you 
weren't really paying attention 
nf0157: right or even more er if you were seeing an old man crossing the road 
and you weren't paying much attention i m-, 
sf0177: you were too busy thinking about this 
nf0157: this 
sf0177: awful thing that had happened the other day 
nf0157: 
yeah er this ho-, dreadful thing right okay i mean this seems to be true that 
sometimes the things that we think about or reflect about can be much more 
forceful yeah namex 
sf0178: doesn't she mean though that er that's the idea and impression of of 
the same thing so like it's say if you had a car crash 
nf0157: mm-hmm 
nf0157: okay so that that er reflection when you're thinking about it in your 
mind that might be more forceful than yeah see seeing an old man but would it 
be more forceful than actually being in that car crash 
nf0157: right okay and i think that's a good point and i think that's where he 
he sort of gets his his terminology from that when obviously when you have your 
idea of remembering the the car crash later it is only a faint copy of the 
original impression yeah that's certainly true because the experience when 
you're right there is clearly more forceful but unfortunately that's not going 
to do i mean that's right but that's not going to do all the work that Hume 
wants it to do because he can't he can't make the he doesn't want to make the 
distinction between perceiving and thinking just in terms of of what's going on 
out there he needs to make this distinction introspectively so it's no good to 
say well impressions are the things where there is an external object where 
it's actually happening now or whatever and thinking and reflecting is when the 
object's gone away and you're just looking back on it because that would just 
that would just trivialize this distinction that would just be saying well 
impressions are the things you perceive and ideas are the things you reflect on 
but he wants to make the distinction between perceiving and thinking by talking 
about impressions and ideas so if he just defines it in that way he's not he's 
he's not got a basic distinction between perceiving and thinking he wants to do 
it introspectively he wants to say you can just look into your mind and 
distinguish between impressions and ideas right without referring to what's 
going on outside and the problem is is that 
although in some cases like the one you mentioned it will be quite obvious at 
other times there is other sort of with namex's example you know there are some 
very faint and pathetic kind of impressions and some very forceful lively 
exciting ideas and the distinction just doesn't seem to happen that way 
sf0179: if if you're when he says if you perceive something but it's not 
actually there you you know we're not meant to be relying on the external thing 
but i thought perceiving was relying on the external thing 
nf0157: right exactly i mean this is the problem that he wants to say that 
perception is when you have an impression and thinking is when you have an idea 
i mean he wants to make the distinction between perceiving and thinking in 
terms of forcefulness basically and that just doesn't seem to quite work i mean 
that that's the problem that's exactly the problem that it seems that you can 
have a forceful im-, a forceful idea a forceful mental experience even 
when there's nothing there so it's just not true that the perceptions the real 
perceptions are always more forceful than the things you reflect on and Hume in 
fact admits that i mean he says sometimes you know our er our ideas our 
impressions of our ideas are very lively and our impressions are so low and 
faint that you can't really distinguish them from my from impressions but 
generally we know what we mean 
well okay er okay how does Hume argue for this distinction how does he rely how 
does he argue for the very very important principle which is that every simple 
idea must come from a simple impression because this is the the touchstone of 
his empiricism this is the principle on which he bases his criticisms of cause 
his criticisms of personal identity right so his basic philosophical method is 
going to be saying that here's a philosophical term here it is like like 
substance where's the impression from which this idea is derived if we can't 
find one 
then it's insignificant that is his big philosophical argument and it relies on 
empiricism so it's pretty important for him to argue for this principle that 
simple ideas are derived from simple impressions well he gives us various 
arguments he he challenges anyone to produce a simple idea that's not derived 
from a s-, from a simple impression he says you know if you want he gives a 
sort of earlier version of the Mary example if you want to teach a child what 
red is do you try and explain it to them no you don't you show them red so for 
with children they get the impression and then they have the idea that's the 
order it goes in and he gives the example of a a blind man so that was Erika's 
example a deaf person he said look a blind man can form no idea of colours er a 
deaf person will have no idea of sounds er someone who's never tasted a 
pineapple doesn't know what a pineapple tastes like they have no idea of the 
taste of pineapple okay so that's his argument er 
unfortunately he then offers a very famous counter-example to his own argument 
which is a bit of a a strange thing to do er and this is the example of the 
missing colour shade so i'm just going to talk about that for two minutes and 
then we'll stop er and this this example of Hume's is let's just imagine that 
we have a man who's facing a sort of a series of colours so we start with say 
we s-, with blue say we start with dark blue and we move along the colour 
series to light blue one into the other but in the middle there's a gap and the 
the the gap corresponds to a shade yeah so everyone got the picture so you've 
got dark going to light and there's a gap where one of the shades would be and 
as it happens that shade is not a shade that the person who's looking at the 
colour series has ever seen before so he hasn't had an impression of that 
missing colour shade and Hume says can the man form an idea of the missing 
colour shade from the series presented to him 
what do you reckon can he who thinks he can [sniff] right who anyone think he 
can't right okay so so Hume says yes it does seem plausible to think that he 
can in fact form an idea of the missing colour shade when he's had no 
impression of this and what he says about this example is what's he say about 
this example er he says is it possible for him to supply this deficiency and 
raise up to himself the idea of that particular shade though it had never been 
conveyed to him by the senses i believe there are few that will be of the 
opinion that he can as has been empirically demonstrated in this class and this 
may serve as a proof that the simple ideas are not always derived from 
correspondent impressions though the instance is so particular and singular 
that 'tis scare worth our observing and does not merit that for it alone we 
should alter our general maxim so that's not very good really and then there's 
an enormous literature of 
course in the Hume literature saying well why did Hume do this why having 
proposed this general theory which is so important to him does he then offer us 
this counter-example and of course if you well you can go away and read this 
for yourselves er okay what do you reckon so let me remind you by the way that 
about twenty minutes ago y-, you you seemed maybe to be going for this 
principle that we can't have a simple idea without a simple impression yeah 
namex 
sf0180: i don't think it's quite the same because it's not it's the whole thing 
about not being able to have a simple idea 
nf0157: mm-hmm 
sf0180: without the simple impression but i think if you say with the example 
of the shades of blue 
nf0157: yeah 
sf0180: you've given them sort of ninety per cent of the idea 
nf0157: mm-hmm 
sf0180: and they've got to fill in from that so say somebody who never ever 
seen red at all if you gave them the whole spectrum of red with a bit missing 
nf0157: yeah 
sf0180: they will be able to fill that in 
just by sort of you know working it out from what's there 
nf0157: right 
sf0180: you're not asking them to create anything from nothing 
nf0157: right 
sf0180: if you've given them so much to work from 
nf0157: right and i mean act-, actually that's that's very interesting because 
that is basically the line that er Harold Noonan takes and i was going to say i 
didn't bring with me though that you know those Routledge blue and green books 
like there's the one on Locke by E J Lowe and there's the Hume one by guy 
called Noonan and that's very good and that's pretty much the line he takes but 
i mean there are there are various things i mean that seems to imply that maybe 
colour shades are not simple ideas that we can sort of derive them from putting 
together other things the the i suppose 
the one problem with that is that Hume did think that colour shades were simple 
ideas it doesn't really explain why he offered this as a counter-example and 
then er changed his mind 
sf0181: maybe he didn't know how light worked though because i guess you could 
nf0157: mm-hmm 
sf0181: put it in a scientific sense 'cause 
nf0157: yeah 
sf0181: you know different pure shades of light 
nf0157: yeah they're they're different they're different wavelengths and and 
then we can yeah i mean sure and maybe that's just maybe that's just er a an 
unfortunate fact about Hume's empiricism but of course you've got then got to 
think well how far does this apply to any kind of sense data theory about about 
perception about what objects are er okay final thought i mean one thing does 
this undermine Hume because if it does we might as well stop here and i mean i 
think the interesting thing is that one can tell various stories about why this 
might not undermine Hume but i think the bottom line is that this principle for 
Hume is very important and he will go on to apply it in various areas and this 
particular counter-example doesn't really seem to undermine his ef-, efforts to 
apply this principle in other areas so particularly in the idea of causation 
the idea of personal identity that seems to be quite a different kind of 
principle okay so next week belief