Causality

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Causality
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What is a cause?

• On September 11, 2001, the World Trade Center
  Towers collapsed. What caused them to fall?
• Heath Ledger died in January of 2008. What
  caused his death?

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Hume

• Relations of ideas
• Ideas are truths that are independent of human
  reasoning
• Triangles have 3 sides whether or not there are
  people to think about them
• Matters of fact
• Facts must be perceived or created by humans
• Causes are matters of fact, not ideas

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What leads to causal inferences?

• Physical proximity
• Temporal proximity
• Channel for action
• Similar causes lead to similar effects
• Generalization from past instances
• The DP rule
• DPp(EC) - p(EC)
• A cause must change the probability that some
  event occurs

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Simple launching events

• The standard event is seen as causal
• If the balls do not touch, then it is not seen as
  causal
• If the balls come together and stop and then the
  second one moves, it is not seen as causal

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Causes and counterfactuals

• Counterfactual statements
• Statements that presume some event had not
  occurred.
• If I hadnt eaten so much, I wouldnt feel sick
  now.
• Counterfactual reasoning is related to causality
• People must be able to reason about what would
  have occurred had the putative cause not happened.

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Causes and explanations

• Causes presume some type of explanation
• The type of explanation desired sets the context
  for the cause
• Many different things may be seen as causal
  depending on the type of explanation required
• Levels of explanation in Psychology (Marr)
• Computational-level explanations
• Algorithmic-level explanations
• Implementational-level explanations

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