RE: Modal ontological argument
February 1, 2022 at 3:27 pm
(This post was last modified: February 1, 2022 at 3:28 pm by HappySkeptic.)
From Quora:
When either are using the word "possibly", they are trying to make either a De Dicto or De Re statement. The word "possibly" in modal logic does not mean "hypothetically", it is a statement of actual necessity.
Therefore, these arguments contain the conclusion in the premise, but the premise is completely false. The English language is what lets us down. The same arguments can be used to "prove" that a God does not exist, or that Santa Claus exists or does not exist.
Quote:De Dicto (of the proposition): The scope of the modal operator ranges over the entire statement, [Necessarily, there is some X such that it is A].
De Re (of the thing): The scope of the modal operator ranges over a particular element/variable, [There is some X such that it is necessarily A].
Thus, De Dicto statements have an existential quantifier within the scope of a modal operator, while De Re statements have a modal operator within the scope of an existential quantifier.
Existential fallacy: a formal fallacy where a class is presupposed to have members, but the argument did not state or assume that it does in fact have members.
When either are using the word "possibly", they are trying to make either a De Dicto or De Re statement. The word "possibly" in modal logic does not mean "hypothetically", it is a statement of actual necessity.
Therefore, these arguments contain the conclusion in the premise, but the premise is completely false. The English language is what lets us down. The same arguments can be used to "prove" that a God does not exist, or that Santa Claus exists or does not exist.
