DAVID HUME

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DAVID HUME
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David Hume (1711-1776)

• Hume and the Enlightenment
• The project of epistemology what can we know?
• Hume and Descartes

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Two Kinds of Knowledge

• Relations of ideas (IV, I, 1)
• A priori (thought)
• Not about the world
• Matters of fact (IV, I, 2)
• a posteriori (experience)
• About the world

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The Basis of Empirical Knowledge

• Two sorts of matters of fact (IV, I, 3)
• Known by immediate experience
• Known by reasoning from immediate experience
• Basis of reasoning from immediate experience
  cause and effect (IV, I, 4)

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Knowledge of Cause and Effect

• Humes question How do we know that a given
  cause has a given effect? (IV, I, 6-11)
• Not by purely logical reasoning (relation of
  ideas)
• Therefore, from experience (matter of fact)
• But how does experience give us knowledge that C
  causes E? (IV, II, 1)

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The Problem of Induction I

• We believe that C causes E because of our past
  experiences of C being followed by E
• But do past experiences support conclusions about
  the future?
• Only if we know that the future will (probably)
  be like the past.
• But how do we know this?

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The Problem of Induction II

• Two ways of knowing that the future will be like
  the past
• A priori (reasoning) no, because future might
  not be like the past (IV, II, 5)
• A posteriori (experience) no, because that begs
  the question (IV, II, 6)

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Humes Conclusions

• We have no basis for believing that the future
  will be like the past (IV,II, 8)
• Belief that the future will be like the past is
  based merely on custom, not knowledge (V, I, 5-6)
• Therefore, beliefs in causality are likewise
  based merely on custom
• Therefore, so are all beliefs about the world
  that go beyond immediate experience

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Is Hume a Skeptic?

• Yes, in the sense that he claims there is no
  justification (rational argument) for our beliefs
  about the world.
• No, in the sense that he denies the need for any
  justification of these beliefs.

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Miracles and Religious Belief

• Humes empiricist approach
• The claim that there have been miracles is a
  claim about a matter of fact
• Claims about a matter of fact must be settled by
  an appeal to experience
• Conclusions based on experience have degrees of
  certainty (probability) depending on the amount
  of evidence supporting them.

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Miracles and Testimony

• Testimony the main source of evidence for
  miracles
• Testimony evaluated by
• Reliability of the witness
• Probability of the claim made

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The Probability of a Miracle

• Miracle violation of a law of nature
• Law of nature a uniformity supported by all our
  past experience
• Probability likelihood of an event given past
  experience
• A miracle is contrary to all past experience and
  therefore is maximally improbable

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Should We Believe Testimony of Miracles?

• 1. The intrinsic probability of a miracle is
  maximally low.
• 2.The probability that a witness to a miracle is
  wrong is not maximally low.
• 3. Therefore, it is more probable that a witness
  to a miracle is wrong than that the miracle
  occurred.
• 4. Probability is the guide to what we should
  believe about matters of fact.
• 5. Therefore, we should not believe any report of
  a miracle.

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The Force of Humes Argument

• Does not deny that miracles are possible.
• Does not say that no miracles have ever occurred.
• Does not say that we could not have good reason
  for believing that a miracle has occurred.
• Does say that we have no good reason to believe
  any actual reports of religious miracles.

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Some Responses to Humes Argument

• Deny that miracles are violations of laws of
  nature
• Deny that factual beliefs should always be based
  on probability
• Recognize that faith is the basis for accepting
  miracles not vice versa