Suppose that someone initially states that "fossil fuel consumption due to mobile phone usage is similar to that of private transportation, so if you think we should switch to electric/bike to fight climate change, then you should also stop using your mobile".

You call bullshit on that statement, and the debater replies by citing a paper which shows that "worldwide, the fossil fuel consumption of all communication networks, including the Internet is estimated to be about half of the fossil fuel consumption for transportation".

Now the statement is true, but this is not the original statement: it has been unduly extended to make it true. What's the name of this logical fallacy?

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    I made an edit for clarity which you may roll back or continue editing. Welcome to Philosophy! Mar 20, 2019 at 13:29
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    This may or may not be a fallacy, but is frequently referred to in debating as "moving the goalposts": they've implicitly or explicitly redefined the the thing you're arguing about. Mar 20, 2019 at 17:01
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    This may not even be a case of moving the goalposts as much as more precisely defining ones' terms. Conversation is not a carefully constructed paper delineating how each point is constructed. (I'm not referring to this particular discussion, or the points therein but rather the development of a discussion.)
    – Mayo
    Mar 20, 2019 at 17:06
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    The implied argument is something like this: you consider using your cellphone justified; there is nothing special about you, therefore, you consider everybody's use of cellphones justified; the fossil fuel consumption of that is comparable to that of private transportation; so why should we alter one rather than the other (or both). This is a legitimate point. Unless you can draw a meaningful disanalogy between using cars and cellphones, your reply should be: yes, we should switch to solar/wind for powering cellphones as well.
    – Conifold
    Mar 20, 2019 at 19:52
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    Yes, that is what she likely meant. The fallacy is known as tu quoque (appeal to hypocrisy). The side point about hypocricy does not address the issue of whether the change in behavior should happen or not. But the "extension" part is not in itself fallacious, and the relative impact response is weak. Usage of cellphones and cars accumulates into the same total, whether we group cellphones separately or with communications. And the latter blocks the potential attempt to say that "they are insignificant".
    – Conifold
    Mar 20, 2019 at 22:20

7 Answers 7


Fallacy of division :

A fallacy of division occurs when one reasons logically that something true for the whole must also be true of all or some of its parts.

The assumption of the fallacious argument is that "the fossil fuel consumption of all communication networks, including the Internet, is estimated to be about half of the fossil fuel consumption for transportation".

The conclusion that "fossil fuel consumption due to mobile phone usage is similar to that of private transportation" is fallacious because incorrectly extrapolate, from the fact that mobile phones are part of overall communication networks, that also the fuel consumption of mobile phone usage must be comparable to that of transportation.

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    Could also be straight non-sequitur. Their extended argument isn't the same. Could be some sort of slippery slope... depends on context probably.
    – Richard
    Mar 20, 2019 at 12:57
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    @DeltaIV Yeah that's slippery slope. Classic example from the UK comedian Harry Enfield : You have to eat meat, because otherwise the cows will multiply. Then they'll eat all the vegetables and you'll starve, is that what you want? Cos that's what'll happen.
    – Richard
    Mar 20, 2019 at 15:41
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    @Richard Cows eat a mixture of grass hay, alfalfa hay, grains as well as corn and grass silage - mostly plants that humans would not eat. Cows fertilize vegetables. Not eating cows would lead to more vegetables.
    – emory
    Mar 20, 2019 at 16:33
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    Perhaps not a fallacy, but it edges toward whataboutism (what about-ism). Link: en.wikipedia.org/wiki/Whataboutism
    – cmm
    Mar 20, 2019 at 20:48
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    @DeltaIV This answer is incorrect. What would be the property that does not divide? It is bad to use fossil fuels for communications in general, but it is not so bad to use them for cellphones (or some other component) in particular? Your opponent's fallacy is not where you are looking for it, universalizability is an established ethical principle. If one is serious about limiting fossil fuel consumption they do not get to restrict that to a specific type of it, be it cars, communications, or cellphones. They all share in the bad.
    – Conifold
    Mar 20, 2019 at 22:41

The OP presents a situation wondering if a logical fallacy has been committed.

The following claim is made:

Fossil fuel consumption due to mobile phone usage is similar to that of private transportation, so if you think we should switch to electric/bike to fight climate change, then you should also stop using your mobile.

The claim is denied without argument.

The person making the claim provides evidence by citing a paper which shows that

worldwide, the fossil fuel consumption of all communication networks, including the Internet is estimated to be about half of the fossil fuel consumption for transportation.

The paper's worth is acknowledged:

Now the statement is true, but this is not the original statement: it has been unduly extended to make it true. What's the name of this logical fallacy?

What needs to be done next is to see how much of the fossil fuel consumption in the report was attributed to mobile phone use.

If the report doesn't have that breakdown one can raise a question about the usefulness of that report. If it does, use that particular number to see if mobile phone use is relevant or not.

Raising a logical fallacy in an argument can backfire. Those listening (the audience) may start siding with the other side as a result. Bo Bennett also warns that if one does start pointing out an opponent's fallacies the opponent may start doing the same. That tactic of calling an opponent's argument logically fallacious may be a distraction or red herring which can itself be logically fallacious.

Here is Bennett's description of red herring:

Attempting to redirect the argument to another issue to which the person doing the redirecting can better respond. While it is similar to the avoiding the issue fallacy, the red herring is a deliberate diversion of attention with the intention of trying to abandon the original argument.

The issue at this point in the argument is whether the data in the report can be used to justify whether one should stop using one's mobile if one wants to fight climate change. Is the associated fossil fuel used large enough? That needs to be addressed and the opponent has taken a risk by providing evidence which can be critically examined.

Bennett, B. "Red Herring" https://www.logicallyfallacious.com/tools/lp/Bo/LogicalFallacies/150/Red-Herring

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    ouch, now I'm a difficult position :-) both answers are really nice. I like your "analytical" examination of the opponent's claim, and the indication about the next steps to advance the debate. On the other hand, I did ask explicitly for the fallacy name, which the other answer gave. I would say that the other user answered the question I asked, and you answered the question I should have asked.
    – DeltaIV
    Mar 20, 2019 at 15:10
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    @DeltaIV Except that the accepted answer does not appear to be correct. What is the statement of fact that is made for a whole? What are the individual parts, and how is the statement of fact being incorrectly applied to one or more of them? No, it looks like this answer does answer the question that you asked, and does so the best.
    – Aaron
    Mar 21, 2019 at 20:18

This sounds like an example of Moving the Goalposts.

"Let me cite this paper which proves my assertion that fossil-fuel-derived energy for cellphone use is equal to the same kind of energy consumption by cars. Look, see right there where it proves that all communications network traffic, including cellphones, uses half the fossil-fuel-derived power that cars use? Goal achieved."

The opponent changed how success was defined in the middle of the discussion.


Sounds like an appeal to extremes:


"An argument of the form 'if X is true then Y must be true' where Y is the extreme."

Could also be called 'reductio ad absurdum' according to the same page; basically someone continues your argument into the absurd in an attempt to disprove it

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    reductio ad absurdum is not a logical fallacy. Appeal to extremes is an incorrect application of reductio ad absurdum, and is a logical fallacy.
    – YiFan
    Mar 20, 2019 at 23:04
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    The person bringing up the data was not trying to make their claim absurd but to justify it with the data about worldwide fossil fuel consumption for communication networks being half of the fossil fuel consumption for transportation. Such data should be checked further to see how accurate it is. Mar 20, 2019 at 23:51
  • @FrankHubeny i think YiFan has a point though.. the argument i thought was slippery slope is a kind of reduction to the absurd. If we're banning cars, we'll.have to ban hearing aids, and cheap.spectacles... etc
    – Richard
    Mar 22, 2019 at 0:43

It sounds like there is no fallacy. How has the statement been "unduly extended"? A statement was made, and evidence was provided to back it up. That sounds very duly extended.

You have a discussion where the initial assumption being accepted as an axiom is "We should try to reduce climate change by reducing fossil fuel consumption," and the discussion includes "We should convert to electric and/or bikes." This is the point being debated, "We should convert to electric and/or bikes."

Given the statement which is accepted as an axiom by those involved in the discussion (that global warming is bad and we should reduce fossil fuel usage to reduce global warming), "We should convert to electric and/or bikes" (roughly equivalent to saying "We should stop using vehicles which consume fossil fuels") is a fine point. However, "We should stop using wireless communications, as they consume almost as much fossil fuel" is an equally valid point. And, all other things being equal, you might as well accept both or reject both equally.

Therefor, it is perfectly reasonable to insist that the two proposals have the same outcome, that either they are accepted or rejected together as one. There is nothing wrong with this, and there is no fallacy so far. There is no logical necessity to demand that the proposals have the same fate, but there also is no problem with making that demand either; it is neither here nor there.

If you desire to have the two treated differently, then what you must do is provide a reason that they should be treated so. Remember, I said "All other things being equal," so provide some logic showing that they are not equal.

Further debate may well cause the other person you speak of to rely on logical fallacies to support their argument, but merely stating that "If A is roughly equal to B, then we should accept or reject them together" (ie: "Transportation and communication are roughly equal fossil fuel users, therefore we should accept or reject them together") is not a fallacy. Indeed, the onus of burden is on you to suggest why two equal things should be treated differently.

There are plenty of things that the debater you mention could have said which would change the answer, but we cannot assume anything and must go only with what information you have provided. So the answer is "No solution - there is no logical fallacy therefore no name to provide."


It's a straw-man argument because the argument assumes that the only reason that the person making the proposal selected the e-bikes project was the amount of carbon emissions from cars. In reality, there could've been all kinds of considerations that lead to them suggesting that particular project.

You could make a case that this is a slippery slope argument, but I think that that is less of a fit.


It's arguing from false premises, but I don't think that's a logical fallacy as such.

Socrates is a Greek.
All Greeks are carrots.
Therefore, Socrates is a carrot.

Logically correct, factually ... not so much. Garbage in, garbage out.


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