The existential fallacy, or existential instantiation, is a logical fallacy in Boolean logic while it is not in Aristotelian logic. In an existential fallacy, we presuppose that a class has members even when we are not explicitly told so; that is, we assume that the class has existential import.
An existential fallacy committed in a categorical syllogism is invalid because it has two universal premises and a particular conclusion. In other words,...
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The existential fallacy, or existential instantiation, is a logical fallacy in Boolean logic while it is not in Aristotelian logic. In an existential fallacy, we presuppose that a class has members even when we are not explicitly told so; that is, we assume that the class has existential import.
An existential fallacy committed in a categorical syllogism is invalid because it has two universal premises and a particular conclusion. In other words, for the conclusion to be true, at least one member of the class must exist, but the premises do not establish this.
In modern times, presupposition that a class has members is seen as unacceptable. In 1905, Bertrand Russell wrote an essay entitled "The Existential Import of Proposition", in which he called this Boolean approach "Peano's interpretation".
The fallacy does not occur in enthymemes, where hidden premises required to make the syllogism valid assume the existence of at least one member of the class.
Let S=subject and P=predicate....
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