What is Ad Hoc?
Following up a disputed argument with a new claim that cannot be proven.
Business Application
Ad Hoc arguments can sometimes be detected easily but can often be very convincing. A popular method of calling out a person’s claim on the internet is to ask them to “Cite your sources.” In person, digging a little deeper with “How did you hear about that?” or by pointing out that the supporting claim cannot be proven will be very effective in countering this fallacy.
Example
Argument –
My investor brings me back 30% returns on a monthly basis.
Counter Position –
There’s no way an investor could bring in those types of returns, that consistently, unless they’re doing something illegal.
Ad Hoc –
Well maybe he has some sort of proprietary algorithm or he has some great insider knowledge.
Why This is a Fallacy
Inserting possible explanations without new supporting evidence to counter an argument is a very common use of the Ad Hoc fallacy.

Tom Waters
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