Welcome to the sixth Hume lecture. Today we're going to be finishing off with causation and talking about a few interpretative issues.
And then we're going to be moving on to book one for looking at the sceptical problems that arise in one for one and a bit of one for two.
So last time we looked in some detail at Hume's discussion of the idea of
necessary connexion causal necessity that largely structures but one part three,
of course, we noted some tensions in Hume's texts.
We saw that Hume seems to be a clear believer in causation.
He has positive things to say about causation.
He's not just a negative sceptic about it, and he identifies what seems to be a legitimate impression of causal necessity.
So his search for an impression of necessary connexion succeeds.
So a note of sort of summary of causation significance for whom some of this goes back to what I was saying in the first lecture,
causation is a crucial relation for whom it is the only way that we can get a legitimate inference from one thing to another,
from observed to unobserved. The one three,
which I've already noted is the longest part of the treaties and the one on which he focuses most in the abstract covers a
lot of topics with which you is particularly associated topics that are very important to him and his analysis of causation.
I'll be saying a little bit more about this later. Crucially, impacts on discussions in that come later in the treaties.
So we've got generally from whom a positive picture of causation.
Let's now look at some interpretative issues,
and here I'm going to be expressing some scepticism about two popular trends in relatively recent human scholarship.
So one of them is the so-called new Hume. This is a view of Hume that emerged in the 1980s.
It's enjoyed quite a lot of vogue for a couple of decades. I think it's very much on the decline now.
But the claim made by the new humans who differ in various ways, but in general,
their thought is that when humans discussing our idea of causal necessity, he's not talking about causation as it is in itself.
He's not talking about the meaning of causation. He's simply talking about our epistemological grasp on causation.
And that normally goes along with the idea that causation, real causation would be something deeper,
something that is inaccessible to us, something which, if we did know about it, would licence a priori inference from cause to effect.
So here we've got the so-called ape conception. So the claim here is that when there's a real causal relation, a genuine one,
there is something in the cause which is such that if we knew about it, it would licence a priori inference to the effect with total certainty.
Now an obvious problem with this idea of or alleged idea of human causation is that it seems to conflict with the conceivable principle.
Hume states again and again around 30 times, actually.
He puts forward the conceivable principle that whatever we conceive is possible.
Now, he also says repeatedly that whenever there is a cause and effect relationship, we can conceive of the cause without the effect.
That's why for us, a priori inference from calls to effect is completely impossible.
Now, if you put those two together, there is a clear tension in the new human account.
The new humans have old John Wright and Peter Cahill have suggested possible responses to this, but their responses run together.
The conceive ability and the inconceivable principle and they look at passages in which Hume suggests some limitation on the
inconceivable principle and want to conclude that actually Hume is not a completely committed to the conceive ability principle.
I think that's implausible simply because there are so many times that Hume appeals to it.
The only significant evidence in favour of Hume having a conception like this is this
passage from the treaties and various passages in the enquiry that I'll mention in a moment.
So to be able to concede power in some particular being,
we must distinctly and particularly conceive the connexion betwixt the cause and effect and be
able to pronounce from a simple view of the one that it must be followed or preceded by the other.
This is the true manner of conceiving a particular power in a particular body.
Now, if you read that in isolation, it does suggest that a true conception of causation would be something that licence is a priori inference.
And the problem is this passage comes from a section, a paragraph in one 314,
where Hume is objecting to the thought that we might be able to get some abstract idea of causation.
He's asking, how do we get the idea of a causal necessity?
And he's dealing with the thought that we might go straight to an abstract idea,
and he's saying we can only get an abstract idea where we've had a particular idea.
And he's addressing that in this paragraph.
Nevertheless, you might look at that and think, OK, that does suggest the AP criterion.
If we look at the enquiry, what I've called the key move that Hume appeals to six or more times within the enquiry text.
That's Enquiry Section seven, Hume seems to be saying, Can we get an idea of the necessary connexion in this particular case?
If we could, then we would be able to make an a priori inference from one to the other.
But we can't. Therefore, we can't get an idea of necessarily connexion from that.
So, for example, my command over my body, if I think of raising my hand,
would I be able to infer a priority from making that the intention of raising my hand or attempting to do so that my hand would actually rise?
No, I can't. I only know that through experience. Therefore, I cannot get an idea of necessary connexion from that.
So these are the passages in Hume's text that most support the a priori criterion.
But crucially, these passages only occur in the first part of Hume's discussion of the idea of necessary connexion.
They occur before he has considered the idea of repetition.
So they all arise in a context where humans asking Can we get an idea of necessary connexion from a single case?
Is there some impression there that will give rise to the idea?
Now we know from other passages in Hume that he pretty much takes for granted that any a priori inference has to yield certainty.
He thinks all probable inference is based on experience.
So if there were an inference in advance of experience, it would have to be one that yields absolute a priori uncertainty.
So I think that that explains why Hume uses that criterion in that part of the argument,
and it's noticeable that once he does identify what he takes to be the true impression of necessary connexion,
the one that comes from habitual inference, you'll notice that that doesn't satisfy the AP criterion.
OK, so on the new human account, he sets a criterion for what would count as a genuine impression of necessary connexion,
namely one that would licence a primary inference.
But then, when he successfully identifies an impression, he identifies one that doesn't have this characteristic.
So there's I think, more of a puzzle on the new human view than there is on mine.
I can explain why he seems to apply in a pipe. AP criterion that that's because he has not yet considered repetition.
Now, John Wright has a different approach. He doesn't go for the P criterion,
but he like highlights texts that suggest that Hume takes our thinking about causation to involve a parent in conceive ability.
Of course, without the effect. So this is a particularly favourite passage.
It is natural for men in their common and careless way of thinking to imagine they
perceive a connexion between such objects as they have constantly found united together.
And because customers rendered it difficult to separate the ideas, they are apt to fancy such a separation to be in itself impossible and absurd.
Well, OK, that does suggest that Hume thinks that ordinary people thinking about causation sometimes conflate it with conceptual connexion,
but humour immediately goes on to say this is a mistake. So if you really thought that this was the correct way of thinking about causation,
he would have to be a sceptic about causation rather than the believer in it.
What else has supported the new? Well, I think actually the the main argument that made it popular, the new account was from Stralsund,
and what Stralsund did was point out lots of cases where human seems to be referring to causation.
Sincerely. So this is in a context where at the time a lot of people tended to think that Hume was a sceptic about causation.
And so what Straw was doing was pointing to passages where Hume seemed to be referring to causal powers in a very positive way.
So he really did believe in them. And Stralsund took it that because Hume was referring to causal power.
Sincerely, Hugh must mean something like the new Hume type of causal powers.
OK, so here are some of the passages that he referred to that take the one from 416 the secret powers of bodies,
those powers and principles on which the influence of objects entirely depends.
Yeah, it does look like Hume is referring to these powers as though they genuinely exist.
So you can see if if your thought about Hume on the idea of necessary connexion is dominated by all those subjective statements in the treaties.
You know that it's it's in the mind, not in objects and all that stuff, which we discussed last time.
You can see that these passages might seem to be in conflict with that, and you might think, OK, humans got a view of causation,
which is at odds with the official account he gives when he's discussing the idea of necessary connexion.
Well, the same thought, interestingly, occurred to Henry Hume, Lord Keynes, and in his essays concerning morality in natural religion in 1750 one,
he actually accused him of inconsistency because of precisely these references.
Well, in the second edition of the enquiry to the very next sentence of the sentences that came, teams have picked out, Hume attached a footnote.
The word power is here used in a loose and popular sense, the more accurate explication of it would give additional evidence to this argument.
See Section seven.
So I think that completely undermines the the evidence, the alleged evidence in favour of the new houM taken from those passages in the enquiry,
humans saying look at section seven of the idea of necessary connexion to see my account, my precise account of what I'm talking about here.
But there's another point as well, as you saw last time I mentioned that in the enquiry,
humans got a more sophisticated view of causation than he has in the treaties.
In particular, he starts talking about quantitative forces. And force is a concept like power.
Remember when Hume starts his discussion of the idea of necessary connexion,
he says that a whole load of causal terms are more or less synonymous, and that includes force and power.
So I think there's an explanation of why in the enquiry, Hume starts talking a lot about powers in objects.
It's because he's got a more sophisticated view of causation.
Coming now to the most serious objection to the new Hume, and it's essentially to do with the whole drift of Hume's argument of the idea of
necessary connexion and the way in which he applies the results of that argument.
And my claim is that he clearly does rely on the idea that the two definitions,
the culmination of his argument, do capture what genuine causal necessity is.
So, first of all, just a brief summary here, the entire argument of the idea of necessary connexion is structured around the coffee principle.
He's looking for an impression from which the elusive idea is derived.
He describes the coffee principle as a tool for deciding questions of meaning.
He says quite explicitly that he's looking for the meaning or significance of the terms.
And the discussion, of course, culminates with two definitions.
We've seen the definitions we've seen the corollary is that he draws from the definitions,
so immediately after having presented his definitions, he says, here are some corollaries I can draw from it.
For example, there is no distinction between moral and physical necessity.
Now, how could you say that if you didn't think that these definitions captured the nature of necessity?
If we search through the later text of both the treaties and the enquiry for references
back to his discussion of causation and references back to the definitions in particular,
we find that there are basically two uses that he or two main sections where he uses them.
And one of them is of the a reality of the soul. And one of them is of liberty and necessity.
We saw these in lecture one. In the first lecture,
I was suggesting that a major imposition of Hume's philosophy is precisely to investigate the nature
of our idea of necessary connexion in order to shed light on the question of liberty and necessity.
The question of free will. And that's exactly what he does.
And in both of the materiality of the soul and of liberty and necessity,
the arguments turn on the claim that there is nothing to causal necessity beyond the two definitions.
Now remember the new human claim? Is that humans two definitions only capture causation, as it is to us, causation in the object is something else.
It's an unknown something which would licence a priori inference, for example.
But in this argument, and this is the most pithy presentation of it that you can see, I've given up other references there.
It's the argument is repeated in the treaties and in the enquiry. It's absolutely consistent in all three works.
So Hume's opponents must allow this union and inference with regard to human actions, not human actions, satisfy the two definitions of cause.
You get constant conjunction, you get an inference of the mind. They that's human opponents will only deny that this makes the whole of necessity.
They will say there's something else.
But then they must show that we have an idea of something else in the actions of matter, which, according to the foregoing reasoning, is impossible.
Hume is clearly arguing against a new human position. He's denying there's anything beyond the two definitions,
and I simply don't think there's any way to make sense of that passage on the new human account.
Attempts have been made, suggestions made.
If you want to see the gory detail of the discussion,
I wrote a paper in 2011 in which I criticised Bebe Kael and Wright, who'd all attempted to deal with this problem.
But I don't think they succeeded. And I think that the consensus.
Even more in the abstract, it's very, very clear that Hume sees his solution to the problem of liberty in this city as turning on his definition.
Our author pretends that this reasoning puts the whole controversy in a new light by giving a new definition of necessity.
But it can own a definition can only solve the question of necessity if it actually does define what necessity is.
OK, so much for the new him. Another popular view recently popular is the idea that humans some sort of projective
twist about causation that he thinks that when we attribute causation to the world,
what we are doing is projecting our own feeling of inference or something like that.
Now, the idea that humans have rejected this is a popular one, because it seems also to fit with some things that he says about ethics and aesthetics.
So it seems to give a nice unity to humans thought if we see him as being a project of is it about causation as well?
Simon Blackburn is a key figure here.
The two passages that people most often refer to when talking about Hume's projective ism are the two I've put here.
One of them is in one three 14 concerned with causation and one of them is
in the enquiry concerning the principles of morals where Hume is discussing.
Is discussing ethics, so he's discussing moral taste.
So the first passage is a common observation that the mind has a great propensity to spread itself on external objects.
Okay, that sounds pretty project-based, right?
Thus, the distinct boundaries and offices of reason and of taste are easily ascertained.
The one that is reason discovers objects as they really stand in nature without additions or diminution.
The other moral taste here has a productive faculty and gilding or staining
all natural objects with the colours borrowed from internal sentiment raises,
in a manner, a new creation. OK, that sounds very is right.
You've got moral judgements raising a new creation because we feel more moral sentiments,
approval or disapproval, and we kind of objectify them so we paint natural objects with those colours.
Now, the problem here is that the first passage.
Is not him giving his own theory, what he's doing is explaining why there is a bias against his theory.
So he's given his account of the idea of necessary connexion.
He talks about how people will be prejudiced against it, they will think it's ridiculous.
And then he says the country bias is easily accounted for, and then he talks about the projection.
So it's absolutely clear that the projection is a mistake. Whereas in the second case, it is a projection that he approves of.
So I think there is projective ism of assault in the in the latter case,
but it's a mistake to put the two together as though there's some common theme here.
Moreover, in the second passage where he's talking about reason and taste, Reason presents objects without additions or diminution,
as we've seen, he also says in the same paragraph that it's cool and disengaged.
It's the domain of truth and falsehood. Whereas taste.
Gives pleasure or pain and becomes a motive to action.
He's drawing a distinction between reason, which is the domain of truth and falsehood and taste here.
Making judgements that actually motivate us. Hence the colouring with internal sentiment is colouring things with pleasures and pains.
The approval or disapproval? And crucially, in this discussion, it's absolutely unambiguous that causal judgements are on the side of reason.
Causal judgements concerning the tendencies of particular mental qualities, those which is clearly causal.
Right. That's how we identify virtues and vices by the tendencies of mental characteristics.
And Hume here puts those tendencies unambiguously on the side of reason.
So again, you simply can't say Hume has the same view about causation that he does about morality, it's it's quite different.
You might still want to say, well, there is nevertheless a projective element in Hume's theory, and that's true.
But it's not a deep projective element. It's not that humans doing some crazy realist construction of truth in the way that Simon Blackburn suggests.
Incidentally, I think a modern human, you know, might want to go that way, but it's not, I'm saying it's not the way that human goes.
I think the reason Kim's theory looks projective is still has a project of his tone is simply because he's an empiricist.
And when he is trying to identify the source of ideas which are not straightforwardly sensory, he has to look inside.
He's got to find the source of those ideas from reflection since they're not sensory ideas.
So not surprisingly, he finds the impression of necessary connexion in something, in turn the tendency to make inferences.
He finds our impressions of morality, moral and ethical,
ethical that give rise to moral and ethical ideas in terms of certain sentiments, approval and disapproval and so forth.
So there is an element of projection there, but I think it just comes from the empiricism, I don't think it's anything deeper.
OK. So much for an interpretative points.
I do want to highlight an important outcome from Hume's discussion.
He's we've already seen that he comes up with two definitions. He applies them to draw corollaries.
He applies them in order to solve problems like liberty and necessity.
But he also comes out with a positive view about which we should ascribe.
Causation, all objects which are found to be constantly conjoined are upon that account,
only to be regarded as causes and effects, the constant conjunction of objects constitutes the very essence of cause and effect.
Two particulars of essential to necessity is the constant union and the influence of the mind,
wherever we discover these, we must acknowledge the necessity. So to sum up.
This is not a sceptical account of causation. This is a positive account of its nature.
So to finish off, then part one, part three, we get the reason of animals.
Hume's discussion in the region of animals is basically saying that the.
The animals in fur inductively in much the same way as we do, and this is used to corroborate his account of how we do it.
He's given an account of inductive causal reasoning which appeals to habit or custom rather than any kind of rational insight.
And he points out that that fits very, very well with the reasoning of animals.
So the analogy between us and animals corroborates it.
A point I just want to draw your attention to is that no fewer than three parts of the treaties end with sections comparing humans and animals.
This is one of the three. And there's another section, treaties to three,
which ends saying that the analogy between humans and animals is so obvious that there's no need to discuss it.
So you've got four parts of the treaties, essentially where Hume hammers home at the end.
This message of similarity between humans and animals It's not surprising to find that Hume inspired Darwin when he was trying to work out.
The explanation for evolution came up with natural selection, of course.
OK, so here is him pointing out the analogy between humans and animals.
And that's how book one part three ends. And now we're going to go on to book one part for.
We're just going to make a start on this in this lecture, we'll see once the argument of one for one,
which is an extremely important argument from the point of view of human interpretation,
less important in the sort of subsequent history of philosophy.
And then we will go on and just start on one or two of scepticism with regard to the senses,
which is one of the most famous discussions of humans and has been extremely influential.
OK. So first of all, of scepticism with regard to reason.
So the argument starts like this, suppose I am a mathematician and I come up with some demonstrative argument.
Most of the arguments in maths, you think demonstrative and virtually all interesting demonstrative arguments are in maths.
OK, so I solve some equation or whatever with maybe, say, 10 lines of reasoning or something like that.
OK, let's accept that the rules of demonstration are certain and infallible.
Does that mean I will be 100 percent confident of the result of my calculation?
Well, no, because I probably have experience of having made mistakes from time to time.
So I'm not going to be 100 per cent confident.
So knowledge degenerates into probability, what you might have thought would give total certainty becomes uncertain.
So we always to correct the first judgement derived from the nature of the object that is the mathematical judgement
by another judgement derived from the nature of the understanding that is my experience of having made errors.
But how much adjustment should I make? I mean, suppose I'm trying to solve a quadratic equation and suppose I am wondering how confident I can be.
Maybe something depends on it. Maybe whether I get the result right or wrong will make a difference to me financially.
Or maybe I'm trying to calculate how much I should be prepared to pay for insurance against getting it wrong.
So it might matter to me what the probability is.
Well, I'm likely to go by the history, you know, how have I done in the past and I might reckon, well, I've been 95 percent accurate.
How confident can I be in that judgement of ninety five percent accuracy?
Because now I think about it, although I think I've been 95 percent accurate.
I might have judged that wrong. So I need to make another judgement about the accuracy of my judgement about the accuracy of my faculties.
We're obliged by our reason to add a new doubt derived from the possibility of
error in the estimation we make of the truth and fidelity of our faculties.
Well. I reckon that second judgement, the 95 percent one, I'm kind of pretty confident about that,
you know, plus or minus one percent each side by maybe two percent.
Well, according to whom, this second judgement has to weaken the evidence left by the first judgement, this decision,
though it should be favourable to our preceding judgement being founded only on probability must we can
still father our first evidence and must itself be weakened by a fourth doubt of the same kind and so on.
In infinitum. Even the fastest quantity must in this manner, be reduced to nothing.
All the rules of logic require a continuing diminution. And at last, a total extinction of belief and evidence.
Now that's rather quick. All right.
That's extremely quick. He said. We've got to adjust our mathematical, you know, 100 percent judgement.
To take account of our fallibility. That seems very reasonable.
Yes, OK, I'm only 95 percent sure because 19 times out of 20 in the past, I have got quadratic equations right?
But then he's saying, I should ask how confident I am about that 19 out of 20 judgement.
And then I've got to ask how confident I am about the judgement of how accurate I am in that 19 out of 20 judgement and so on.
So he's just taking it for granted now that we've gotten an iteration,
set up a vicious regress whereby our confidence is going to be further and further diminished.
We'll come back to that in a moment. Let's ask, does Hume actually accept the argument?
Well, he says, no, he doesn't accept it. He actually thinks it's a good argument, but he finds himself unable to accept the conclusion.
The conclusion you see is that we shouldn't have any belief at all because he started with a demonstrative argument.
He showed that even in the case of demonstration, we shouldn't be 100 percent certain, and that kind of seems reasonable.
So that reduces it to probability. And then, he says, whenever we make a probable judgement, either about a demonstration or about anything else,
we should start iterating by asking ourselves how confident we are in the judgement that we've
made and then asking ourselves how confident we are in that judgement of confidence and so on.
But he himself finds himself unable to relinquish all belief nature by an absolute
an uncontrollable necessity has determined to judge as well as to breathe and feel.
Nor can we any more for better viewing certain objects in a stronger and fuller
light upon account of their customary connexion with the present impression.
So when we see any followed by B again and again and we see a we cannot forbear viewing,
be in a stronger and full of light expecting B than we can hinder ourselves from thinking as long as
we are awake or seeing the surrounding bodies when we turn our eyes towards them in broad sunshine.
So nobody is so sceptical as to be able to actually relinquish belief, and Hume can't.
So why is he giving this strange argument, this sceptical argument,
which suggests that we should relinquish all belief if he himself is then going to say,
yeah, but I don't actually accept I can't actually act on this conclusion.
Well, my intention in displaying so carefully the arguments of the fantastic set of Iranian sceptics is only to make the reader sensible
of the truth of my hypothesis that all our reasonings concerning causes and effects are derived from nothing but custom,
and that belief is more properly an act of the sensitive than of the cognitive part of our natures.
So. He's presenting this as backing up his argument about induction when discussing induction.
He came to the conclusion that we can't help believing that the future will resemble the past, even though we can't provide any good reason for that.
We just find ourselves believing things in accord with custom.
He's now saying actually, a similar message applies in the case of reasoning in general.
But if we were to follow logic, we would relinquish all our beliefs.
But actually, we can't do that. Nature forces us to have beliefs.
So what's Hume's explanation, then, of how the iterative argument fails to move us?
I answer that after the first and second decision, as the action of the mind becomes forced and unnatural.
And the idea is faint and obscure, though the principles be the same.
Yet the influence on the imagination weakens. Now that does seem quite plausible, I leave aside whether it's a good argument.
That you can see that the argument gets progressively more and more difficult to grasp and keep hold of
when you're thinking about how confident you are in a judgement of confidence about how confident you are,
about a judgement of confidence about, you know, dot dot dot.
It really gets quite difficult to keep hold of what is what you're supposed to be thinking about.
And it is plausible that when you get a very complex argument that has less effect on
us than a very immediate argument because we find it more difficult to get hold of.
So according to whom we are saved by a trivial property of the fancy.
We're saved from total scepticism only by means of that singular and seemingly trivial
property of the fancy by which we enter with difficulty into remote views of things.
Now that's going to be very important when we come to the final section of book one.
That is the conclusion of this book. This result plays a very, very important role.
So the argument of one for one, although, frankly, most people don't take it terribly seriously is a philosophical argument,
does have a very big impact on humans attitude to scepticism in the treaties.
OK. Is the argument actually any good? Well, no, I think the first stage is reasonable enough.
OK, I make a mathematical judgement. Experience suggests to me that I go wrong about five per cent of the time, so I adjust my credence to 95 percent.
That seems sensible. Then it occurs to me that my estimates of five percent might be wrong.
But why should that make me assume that my estimate is likely to be too optimistic?
It might be too pessimistic. It might turn out when I check that I've actually been ninety seven percent reliable.
So why should thinking about how reliable my estimate was, make me adjust my credence down?
Now, some defenders of human David Owen has written and heroically trying to defend Hume's argument, I don't think successfully, but I would advise.
And it's a good, good piece to read if you want to see how it might be defended.
I mean, he suggests that what Hume has in mind is that the more we, as it were, go down the iteration,
our view of the probability sort of spreads out so it becomes completely indeterminate between zero and one.
I don't actually think that fits with Hume's view of probability, Hume doesn't think in terms of ranges of probability,
he thinks in terms of a particular level of diversity, for example.
And it's not clear to me that it's it's coherent either. But in any case, the case for iteration seems very weak.
I mean, when Hugh motivates the argument at the beginning and says we shouldn't be 100 per cent confident he does so
by talking about how we should think of the history of the instances in which our reason has gone wrong.
So when I solve the quadratic equation, Hume is saying, well, the moment think about all those occasions when you've gone wrong.
Make a sort of history of the instances and adjust your credence accordingly.
OK, so I did that. I remembered I was 19 out of 20 reliable with them, so I adjusted my credence to 95 percent.
And there's no argument here that he's being sceptical about memory or about records.
So it's not at all clear why I should get trapped in this iterative regrets.
Ultimately, it seems I've got a good reason for some uncertainty about the original judgement.
If my history of calculation shows that I sometimes go wrong, but there's no reason for going on to further and further levels.
So I don't think Hume's argument is a good one. I mean, most people don't think it's a good argument,
but it is an interesting one in the impact it has on Hume's philosophy will be coming back to that in the last lecture.
OK, so much for one, for one, a very important section in terms of humans philosophy when he wrote the treatise.
By the way, it's an argument that completely disappears after the treaties.
I think Hume came to realise probably that it's not a very good argument.
And given the destruction that it wreaks later in the treaties, I think he did well to try to dispose of it.
Now on to scepticism with regard to the census, this is a very big section, it's a very complicated section, a very famous section.
I'm just going to give a relatively brief account of its main highlights and will only
be starting on it today will come back to it in the beginning of the next lecture.
OK. So Hume starts out in one for two by repeating the message of one for one that the sceptic continues to believe,
even when his beliefs cannot be defended. Sceptical arguments do not actually stop us believing.
So we may well ask what causes induce us to believe in the existence of body, but tis in vain to ask whether there be body or not.
That is a point which we must take for granted in all our reasonings.
So. Here he's announcing that his intention is simply to investigate what causes us to believe in external bodies, external objects.
He's not, he says, going to ask whether external bodies actually exist.
But one of the things that's very confusing about this section is that by the end of it, Hume's attitude seems to have changed.
I began with promising that we ought to have an implicit faith in our senses, but.
To be honest, having gone through all this complex argument, I feel myself at present of a quite contrary sentiment.
And the more inclined to repose no faith at all in my senses or rather imagination than to place in it such an implicit confidence.
So when you read the section, it's important to realise that there's a dynamism in it.
All right. It starts out in one place. Apparently complacently taking for granted, that body exists.
But then it goes through the analysis of the causes that make us believe in body and when he's come to the end of that analysis.
Hume actually feels that these have seriously sceptical implications.
We end up believing in body for no good reason at all. And in fact, the conclusion is that the belief in body is completely incoherent.
But the same kind of dynamism, incidentally, comes in the final section of Book one, the conclusion of this book where again,
we see Hume's views apparently changing during the course of the discussion that makes it quite difficult to pin down exactly what his views are.
And it obviously opens all sorts of interpretative questions.
I mean is, is Hume deliberately choreographing things to go through a charade of changes of mind?
Or is it genuine? Is it that as he's writing it, he is really changing his mind and this is something on which scholars can have different views?
OK, then to go back to the beginning of 142 and how the discussion starts out, it is quite carefully structured.
The belief in body gets analysed into two aspects. There is continued existence of body and distinct existence, so.
When I if I look at something an object, turn away, look back.
I believe that the object has continued in existence when I wasn't looking at it.
And I believe that it's distinct from my perceptions of it. He remarks that these two characteristics plausibly imply each other.
I think it continues precisely because I think it's distinct from my perception.
Oop, sorry. He then goes on to to say what he's now going to try to do.
He's going to consider whether it be the centrist reason or the imagination that produces the opinion of a continued or distinct existence.
These are the only questions that are intelligible on the present subject for us to the notion
of external existence when taken for something specifically different from perceptions.
We have already shown its absurdity. OK, we'll come back to this.
But notice that there's a reference there to treat one to six.
That's of the idea of existence and of external existence. We've not said much about that yet.
It becomes important later on.
What he's saying here is that because all of our ideas are derived from impressions, when we try to think about an external object,
the only ideas we have available to think about it are ones that are copied from impressions.
So if we try to think of an an external object as something completely different from impressions, we can't do it.
We simply don't have the ideas available. OK, so we've got this question, is it since his reason or the imagination that gives us the belief in body?
Well, Hume says it can't be the senses.
Now this can seem a little paradoxical because you think you know the discussion is of scepticism with regard to the senses.
It's all about the senses aren't beliefs in external bodies a paradigm of the beliefs that we get through the senses?
Well, at least in this part of the section, Hume is thinking of the senses purely as sources of impressions.
So a way of parsing this is can we get the belief in external bodies purely from our impressions?
And the answer is no, because impressions, just all bear impressions.
They cannot point beyond themselves. And part of the reason that they can't do it is that our impressions have a sort of transparency,
an impression just is the way something appears to the mind.
So it is what it is when it is, as it appears, all sensations are felt by the mind,
such as they really are, since all's actions and sensations of the mind are known to us by consciousness.
They must appear in every particular. What they are.
So Hume adopts a certain transparency towards our perceptions, impressions and ideas.
And because of that transparency, it's not possible for an impression somehow to point beyond itself.
Now, you might think that it's relatively unproblematic for our senses to present things as external to our body.
But of course, that presupposes that we have identified our body to start with.
And Hume points that out. And he adds various other considerations that I've alluded to there.
Let's go on to reason. The senses can't give this belief in external bodies, he says.
What about reason?
Well, children, peasants, the vulgar in general believe in the external world, but they do so without consulting philosophical reason.
So philosophy informs us that everything which appears to the mind is nothing but a perception and is interrupted in dependence on the mind.
Whereas the Volga confound perceptions and objects and attributes a distinct continued existence
to the very things they feel or see the sentiment then as it is entirely unreasonable,
must proceed from some other faculty than the understanding. Notice that Hume seems to be equating here reason and good reason.
But what he's saying about the Volga is this and you might initially find this very peculiar.
He's saying that the vulgar equate impressions and objects.
And you might think that means that the vulgar think that sensory impressions are objects.
I would put it the other way round, I would say the vulgar on humans,
do you think that we directly perceive external objects so they fail to draw a distinction between impressions and objects?
Now, obviously, that could be debated, but it's perhaps plausible that they do do that it requires a bit of philosophical
thinking to distinguish between the things that immediately appear to your mind,
the impressions that is the sensory impressions and the objects.
Anyway, Hume saying the vulgar don't draw that distinction. However, that means they're simply wrong.
So. They're clearly not getting their belief from reason.
But suppose we philosophers and we do distinguish between perceptions and objects.
So when I see a chair, I have a perception in my mind of a chair and I postulate that there is an object which is giving rise to that perception.
So I'm drawing a distinction between the the thing that is immediately present to my mind.
That's the perception and the object.
So this is the kind of indirect realism that's associated with, for example, John Locke, John Locke would have been the obvious example.
But according to him, even in this case, we cannot justify the belief in the external object by reason.
And here Hume is appealing to his own analysis of a probable reasoning.
The only way we can reason from one object to another human thinks is on the basis of a causal relation.
The only way we can establish a causal relation is by seeing a constant conjunction between A and B.
But in this case, I'm directly acquainted with my perceptions, but I'm never directly acquainted with an object.
I see a the perception, but never the object, so I can't establish a causal connexion,
and therefore I cannot get an argument from probable reason for the existence of external objects.
Notice that here Hume is clearly assuming that if we could get a probable argument from perceptions to objects,
that would count as an instance of reason, so he's clearly treating inductive causal reasoning as an operation of reason.
OK, so the belief in external objects can't come from the senses, it can't come from reason.
It must be due to the imagination. And then the question is how does the imagination give rise to this belief?
Well, according to him, there are two main factors in our perceptions that give rise to it.
One of them is constancy. One of them is coherence. And here is where we'll end today.
So we'll go on from the slide next time. Basically, humans account is that when I see an object and I turn away and I look back.
There is a constancy, the perception that I get of that object is very similar to the perception I had before.
And that leads me into the illusion that the perception the impression has continued in existence, even what while I was looking away.
So that's constancy coherence. He gives the example of a fire where I light a fire.
Maybe I fall asleep and then when I wake up, I look at the fire and it's changed, of course, but it's changed in a coherent way.
It's changed in the way that fires standardly change.
There's evidence of burning this charcoal there instead of wood and a smaller volume and so forth.
So because I see constancy and coherence, that is what me leads me to believe in external objects.
Notice that there is a passage where Hume seems to gesture towards the idea of inference that the best explanation
that is the thought that postulating external objects gives the best explanation of this constancy and coherence.
But human doesn't actually go that way, as we've seen.
He says no reason can't be the source of this, because only constant conjunction and causal relations can do that.
I think it's a bit of a shame that he didn't think in terms of inference the best explanation which might have provided a more plausible,
rational account of how the belief could come about. But as we will see, Hume actually says the belief comes about through the imagination.
But again, constancy and coherence leads us to towards that belief.
So I'll explain that further next time. Thank you very much.