CAUSATION- lec 8

Question 1

Counterfactual conditionals vs. material conditionals

Answer 1

A material conditional is true iff its antecedent is false or its consequent is true.

These are conditionals whose truth or falsity depends on the truth or falsity of their antecedents
and consequents in the way laid down by this truth table

Question 2

counterfactual
conditional

Answer 2

counterfactual
conditional iff the falsity of its antecedent would not entail its truth

Question 3

quantification over possible world

Answer 3

ccount of the truth
conditions for a counterfactual conditional:
‘p □→ q’ is true iff q is true in all of the p-worlds (worlds where p is true) that are as similar to
the actual world as the most similar p-world is. (‘p □→ q’ is to be read ‘p counterfactually entails q’)
This rubric generates a way to decide whether a counterfactual conditional is true:

i) Find the band of p-worlds that are the most similar to the actual world.

ii) Ask whether these worlds are all also q-worlds.

iii) ‘p □→ q’ is true iff the answer to the question at (ii) is ‘Yes’. (Note that if some of the nearest p-worlds are q-worlds but others are not, ‘p □→ q’ (‘If p then it would have been that q’) is false, but the might counterfactual ‘If p then it might have been that q’ is true.)

Question 4

Causation and chains of counterfactual dependence: Lewis’s 1973 view

Answer 4

n ‘Causation’ (first published 1973) Lewis analyses causal relations between events in terms of
counterfactual relations between propositions stating that the events occur. The proposed
analysis has two stages:
.
(1)He defines causal dependence in terms of counterfactual dependence:

One event (e) causally depends on another (c) iff the counterfactuals ‘If c had not occurred, e
would not have occurred’ and ‘If c had occurred, e would have occurred’ are both true. (166-7)
(2)He defines causation in terms of causal dependence:

c causes e iff there is a chain of events (d1, d2, …. dn) leading from c to e such that e causally
depends on dn, dn causally depends on dn-1, … d1 causally depends on c.

Question 5

causation is transitive while
counterfactual dependence is not

Answer 5

But counterfactual dependence is not transitive: you could have ‘p □® q’ and ‘q □→ r’ true but
‘p □® r’ false

Question 6

Lewis’s analysis and transitivity

Answer 6

Lewis’s two stage analysis (causal dependence is analysed as counterfactual dependence, and
causal relations analysed in terms of chains of causal dependence) enables him to provide a
counterfactual account of causation while respecting the intuition that causation is transitive.

This is because he is analysing ‘c is a cause of e’ as ‘c occurs prior to e in a chain of causally dependent events’, and x occurs prior to y in chain Z of causally dependent events is a transitive relation even though y depends causally (counterfactually) on x is not.

So Lewis is at least giving us a contender to be a right counterfactual account of causation. Next time we’ll think about how much fancier counterfactual accounts of causation can get.