# PHL232H1 Lecture Notes - If And Only If

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Published on 2 Nov 2011
School
Department
Course
Professor
Knowledge and Reality Lecture
November 2, 2011
Lewis and Causation
Couterfactual Conditional: conditional whose truth is not guaranteed by
the falsity of the antecedent [or the truth of the consequent]
Conditionals where A is false in the actual world
Involve not just the way things are, but the way things could be
Causation
C causes e iff there is a chain
Pushing a domino: pushing the first one is the initial event and
then it pushes the next one, and the next and so on till it ends
with the falling of the last one. Lewis asks if the pushing of the
first domino caused the falling of the last domino and Lewis says
yes because of the chain of events causing it
Lewis says causation is transitive and causal dependence is not
Transitive means that a causes b and b causes c, therefore a
causes c
The basic properties of relations ** question on exam
A relation is what is expressed by a 2-place predicate
Ex. X loves Y, X is taller than Y, X got here before Y did
If you use one in a sentence, you will make a claim about both X
and Y
Three basic properties:
oSymmetric: iff for all x and y in the domain; if X stands in
the relation of Y, then Y stands in the relation of X. Ex.
Sibling and being in the same room as someone. If
someone is in the same room as you, you are in the same
room as them. Being to the left of someone is not
symmetric
oReflexive: iff for all x in the domain. Ex. Being the same
height as himself and everything is identical with itself. You
will always bare your height to yourself. Can hold between
distinct things.
oTransitive: iff for all x, y, and z in the domain iff. Ex. Is
greater than [if X is greater than Y, and Y is greater than Z,
then X is greater than Z] or being an ancestor of [If John A
Macdonald is an ancestor of yourself and the second duke
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## Document Summary

Couterfactual conditional: conditional whose truth is not guaranteed by the falsity of the antecedent [or the truth of the consequent: conditionals where a is false in the actual world. Involve not just the way things are, but the way things could be. The basic properties of relations ** question on exam: a relation is what is expressed by a 2-place predicate, ex. X loves y, x is taller than y, x got here before y did. Sibling and being in the same room as someone. If someone is your sibling, then they are your sibling. If someone is in the same room as you, you are in the same room as them. Being to the left of someone is not symmetric: reflexive: iff for all x in the domain. Being the same height as himself and everything is identical with itself. You will always bare your height to yourself.