This Or That Fallacy

The fallacy is this. The people who argue this take a true statement: you must choose X or Y [In this case callbacks vs virtual functions ( which as far as I know, are the only two options )] and pervert it into: you must chose Z vs Y where Z is one variant of X. [ In this case message maps vs virtual functions ].

You then prove that Y is not a good option and claim Z, ignore the whole range of options that are not Z. In this case justifying the bastardisation of a callback system by heavily abusing macros because virtual functions don't work.

-- ThaddeusOlczyk

The fallacy is that you must choose between A and B - the belief that there are no other options.

(Actually, you must always choose between the options you know about, ignoring all the possible options that you don't know about. ;-)

Uhm. No. Your approach to problem solving suggests only using known methods, and never inventing new ones. That is not a good approach. -- ThaddeusOlczyk

It's is sometimes called the ExcludedMiddle; I think it goes back to MrAristotle. It is related to the SlipperySlope, which says, roughly, if we give them an inch they'll take a yard. That presents the choice as "nothing" or "a yard" and the middle choice of "an inch" is excluded. -- DavidSaff

I use this fallacy with my daughter when I want her to get dressed: "do you want to wear this outfit or that outfit?". I've also heard this called a GrandmaQuestion?. -- PhilGoodwin

As any mathematician knows, the answer to such a question should be yes -- StephanHouben

But the whole point of this page is that sometimes the correct answer to the question is no. -- A mathematician

I think the answer is mu. See MuAnswer.

A fallacy that Microsoft seems to commit often (see MfcMessageMapFallacy).

I've taken the liberty of splitting the MFC message map vs virtual function argument off into MfcMessageMapFallacy. I'm not sure how to tidy up the rest of this page, but I've done my best. If anyone would prefer me to replace the original, let me know. --RogerLipscombe

Also known as BifurcationFallacy, FalseDichotomy, ExcludedMiddle.

GrandmaQuestion? is a variant, and SlipperySlope is related to this fallacy.