PHIL120 Lecture Notes - Fall 2018 Lecture 6 - If and only if
20 Sep 2018
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Document Summary
When performing logic, you may encounter the term type ". This simply refers to the tendencies or qualities of a given subset, e. g. knights/knaves; truth-tellers; liars) Let"s look at another problem from the island of knights and knaves: A tells abercrombie that they are both knaves. Since a and b could be, independently of each other, knights or knaves, we know that there are four total possibilities (2 x 2 = 4). After going through the all the possible assumptions, you can deduce that a must be a knave and b must be a knight. A tells abercrombie that at least one of them is a knave. Once again there are four possibilities (2 x 2 = 4). After going through the all the possible assumptions, you can deduce that a must be a knight and b must be a knave. This is the only scenario in which a"s statement can be consistent with the types of the two inhabitants.
