PHL105Y November 22, 2004

1
PHL105YNovember 22, 2004

• For Wednesday, finish up to the end of section 5
  of Humes Enquiry Concerning Human Understanding.
  
• For Fridays tutorial, write a page about either
  (1) What custom is and why Hume describes it as
  the great guide of human life (p. 29), or (2)
  how Hume understands the relationship between
  fiction and belief. (Part II of section V)

2
Part II a deeper analysis

• Reasoning about matters of fact depends upon the
  relation of cause and effect
• Our understanding of the relation of cause and
  effect depends upon experience
• But what is the basis of our drawing conclusions
  from experience?

3
The problem of induction

• We have tasted bread in the past, and found it
  nourishing we assume that it will continue to be
  that way in the future. How?
• Past experience tells us how things were how do
  we draw conclusions about future time from that?
  How do you know it is safe to eat lunch today?

4
The problem of induction

• How do we know that nature will go on the same
  way?
• (or that nature will be uniform this gets
  called the principle of the uniformity of nature
  or PUN for short)

5
The problem of induction

• How do we know that nature will go on the same
  way?
• Not through pure reason (because you can conceive
  of a change in the course of nature nothing in
  the sheer ideas forces you to accept that nature
  is uniform)

6
The problem of induction

• How do we know that nature will go on the same
  way?
• not through experience either! (Why not?)

7
The problem of induction

• We have said that all arguments concerning
  existence are founded on the relation of cause
  and effect that our knowledge of that relation
  is derived entirely from experience and that all
  our experimental conclusions proceed upon the
  supposition, that the future will be conformable
  to the past. To endeavour, therefore, the proof
  of this last supposition by probable arguments,
  or arguments regarding existence, must be
  evidently going in a circle, and taking for
  granted, which is the very point in question.
  (23)

8
The problem of induction

• All arguments from experience depend on the
  principle that nature is uniform
• So dont expect an argument from experience to
  prove that nature is uniform (that would be
  circular)

9
The problem of induction

• When we think there is a causal connection
  between two types of event
• (A putting my hand in the fire B feeling
  pain), we believe that events of type A will
  always (must always) be followed by events of
  type B

10
The problem of induction

• When we think there is a causal connection
  between two types of event (A putting my hand in
  the fire B feeling pain), we believe that
  events of type A will ALWAYS (must always) be
  followed by events of type B
• Is it a valid objection to say that we can
  believe in that causal connection even if
  sometimes (like when Ive shot my hand full of
  Novocain) I wont feel the pain?

11
The problem of induction

• When we think there is a causal connection
  between two types of event (A putting my normal
  hand in the fire B feeling pain), we believe
  that events of type A will always (must always)
  be followed by events of type B
• Is it a valid objection to say that we can
  believe in that causal connection even if
  sometimes (like when Ive shot my hand full of
  Novocain) I wont feel the pain?
• No, because in that case Im not in fact working
  with an event of type A anymore Ive changed the
  initial set-up, and I have an event of type A
  instead. Believing in causal connections means
  that every time the initial set-up is of exactly
  the same type, the same effect will result.

12
The problem of induction

• So, how do we come to believe that events of type
  A will always (must always) be followed by events
  of type B?
• Again, its not through pure reason its not as
  though we could deduce from looking that the
  whiteness and softness of bread that it would
  nourish us the substances secret powers have
  nothing to do with its outward appearance

13
The problem of induction

• So, how do we come to believe that events of type
  A will always (must always) be followed by events
  of type B?
• Through REPEATED experience (but how can repeated
  experience tell us something that a single
  experience could not?)

14
The problem of induction

• Why does this matter?
• If there be any suspicion, that the course of
  nature may change, and that the past may be no
  rule for the future, all experience becomes
  useless, and can give rise to no inference or
  conclusion. (24)

15
The problem of induction

• Hume is clear that we DO think that nature is
  uniform he just wants to know why we think that.
• My practice, you say, refutes my doubts. But
  you mistake the purport of my question. .. As an
  agent, I am quite satisfied in the point but as
  a philosopher I want to learn the foundation of
  this inference. (24)

16
The problem of induction

• Is some very subtle reasoning required to learn
  that nature is uniform?
• Hume notes that the most ignorant and stupid
  peasants, nay infants, nay even brute beasts,
  improve by experience, and learn the qualities of
  natural objects, by observing the effects, which
  result from them. (25)

17
The problem of induction

• Hume wants to establish that reason doesnt (and
  in fact cant) establish that nature is uniform

18
The problem of induction

• Hume wants to establish that reason doesnt (and
  in fact cant) establish that nature is uniform
• Our belief in the uniformity of nature is not
  rational (although for Hume this doesnt amount
  to saying we should give it up)

19
Section V

• Sceptical solutions
• of these doubts

20
Humes attitude to scepticism
21
Humes attitude to scepticism

• Scepticism is a way of fighting mental laziness
• every passion is mortified by it, except the
  love of truth scepticism is often attacked
  groundlessly

22
Humes attitude to scepticism

• Scepticism is a way of fighting mental laziness
• every passion is mortified by it, except the
  love of truth scepticism is often attacked
  groundlessly
• We should not worry that scepticism will paralyze
  us nature will always maintain her rights and
  prevail over any abstract reasoning whatsoever

23
The solution

• What makes us infer an effect from a cause is not
  reason but custom or habit
• All inferences from experience, therefore, are
  effects of custom, not of reasoning. (28)

24
Consequences of the solution

• Our grasp of all matters of fact is founded on
  custom our awareness of the world and the past
  is at a deep level customary or habitual rather
  than rational
• (Why does Hume call that a sceptical solution?)