Forrester's paradox, also known as the paradox of gentle murder, is a paradox of deontic logic attributed to James Forrester. It is a version of the Good Samaritan paradox.
Forrester's argument is that, starting from the statements that: it is obligatory (under the law) that Smith not murder Jones, and it is obligatory that, if Smith murders Jones, Smith murder Jones gently, it logically follows that: if Smith murders Jones, it is obligatory, that Smith murder Jones gently. However, if it were actually the case that Smith murdered Jones, it can then be deduced that: it is obligatory, that Smith murder Jones, which contradicts the first statement, leading to a logical fallacy.
A number of arguments have been advanced that Forrester's paradox is invalid, for example that it is the result of a confusion of scope, or a misuse of deduction rules.
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