I remember hearing an anecdote about a philosopher making this kind of argument for intuitionistic logic: you can think about dropping the law of excluded middle, therefore the law must not hold universally; after all, logic is about our thoughts themselves, and whatever logic governs thoughts about the possiblity of discarding the law of excluded middle must not include the law, if it is taking the hypothesis seriously. Therefore, the law of excluded middle is no law at all.
If this way of arguing worked, you could discard any law of logic you could name.
I remember hearing an anecdote about a philosopher making this kind of argument for intuitionistic logic: you can think about dropping the law of excluded middle, therefore the law must not hold universally; after all, logic is about our thoughts themselves, and whatever logic governs thoughts about the possiblity of discarding the law of excluded middle must not include the law, if it is taking the hypothesis seriously. Therefore, the law of excluded middle is no law at all.
If this way of arguing worked, you could discard any law of logic you could name.
In my math school we called it “proof by lack of contradiction”: assume X is true, we haven’t reached a contradiction, therefore X.