On the internet, one is often accused of committing the so-called 'ad hominem'-fallacy, which, according to Sikipedia, is defined as

a fallacious argumentative strategy whereby genuine discussion of the topic at hand is avoided by instead attacking the character, motive, or other attribute of the person making the argument, or persons associated with the argument, rather than attacking the substance of the argument itself

I find this a bit strange. No, when I — say — call somebody "an idiot", I am not necessarily doing it as part of some clever "argumentative strategy" with the ultimate end goal of changing the topic or otherwise diminishing the arguments offered with irrelevant distracting comments. No, I am calling them an idiot because that's ... just my bloody opinion. And opinions is what one shares (along with arguments) in a discussion.

So why do people accuse me of committing a logical fallacy?

In fact, are they not the ones committing a non-sequitur fallacy, as it does not follow from me making an insult that the insult was specifically made in a strategic attempt to discredit their argument?

Basically, my question is, why do people assume that any insult is an ad-hominem fallacy, when, according to the definition, only certain insults are ad-hominem fallacies. The two examples below should demonstrate this distinction. It is fairly obvious which one is a fallacy and which one is an opinion.

Discussion A

Person A: Smoking is healthy because my doctor says so.

Person B: You're a bloody idiot.

Discussion B

Person A: Smoking is unhealthy because my doctor says so.

Person B: You're a bloody idiot. Therefore, we can safely assume your argument to be wrong.

Clearly, only person B in discussion B is committing the ad-hominem fallacy. The other person B is just giving their opinion. And yet, you will find that most people on the internet will describe both responses as ad-hominems. Why is this? Is my definition of the fallacy wrong? What's going on here?

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – user2953
    Commented Apr 7, 2018 at 11:25

13 Answers 13


Because they expect arguments, not inflammatory noise

No, I am calling them an idiot because that's ... just my bloody opinion.

Exactly that: just your opinion. An opinion is not an argument; it is not a syllogism, it is not reasoning, it is not fact, it is not evidence, it is not anything other than just that: your [expletive] opinion.

So why do people accuse me of committing a logical fallacy?

It is true that if you state it as such — "It is my opinion that you are [demeaning characterisation]" — then you have not committed a logical fallacy. You have perhaps gone against good form, or maybe broken a code of conduct, but you have not committed a logical fallacy.

So why did they assume that you were putting forth an argument?

It is because if you say it as "You are an idiot", you have not expressed it as a subjective opinion but as a statement of objective fact. With that you implicitly argue that your comrade in the discourse is not to be taken seriously. The statement therefore becomes a logical fallacy.

It is a fallacy because you have not in any way argued why their arguments are wrong. You have not made a logical statement that refutes their arguments or stance, nor validates your own arguments and/or stance. All you have done is characterise your comrade, and characterisation does not make an argument.

You have directed your argument ("argumentum") towards ("ad") the (hu)man ("hominem") instead of towards their arguments or their stance.

At this point you might want to object and say that you did not explicitly state that it was an argument. But they will make the assumption that this is what you meant anyway, no matter if you intended it to be or not. This is there because in a discourse you are expected to provide arguments pertaining to the discussion you were already having, as opposed to throwing in irrelevant opinions about how you perceive the character of your comrade. Irrelevant opinions are noise; insulting irrelevant opinions are inflammatory noise.

So if you insist on insulting people in a discourse, the alternative to getting called on committing a logical fallacy is to get called on polluting the discourse with inflammatory noise...

...that is to say: trolling/flaming.

I do not know about you, but I much rather prefer being accused of committing a logical error than being accused of being a troll or a flamer.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – user2953
    Commented Apr 7, 2018 at 11:25
  • On the contrary, an argument is an opinion: it is an opinion on which of, and in what sequence, the axioms and rules of logic are used to get from the premises to the conclusion. What you call "inflammatory noise" is either an argument you deem to be trivially false (such as a conclusion with no usage of the rules of logic or the axioms - like calling someone an "idiot") or an actual argument, but the existence of whose usages of the rules of logic and the axioms you reject. To improve this answer, the demarcations between "arguments" and "opinions" need to be rigorously specified. Commented Nov 24, 2018 at 15:52

If an opinion isn't intended as an argument, it is noise

Frankly, nobody wants to hear your opinion unless you have some point to make about it.

You can have the opinion that a person is an idiot, but if you're putting in the effort to type it in then you obviously have some point to it.

I don't state every opinion I have on every post I make on the internet. If I state one of my opinions, it's because I believe it is relevant. And if you are trying to claim that this insult is relevant to the argument (which you implicitly do by sharing it), you commit ad hominem.

In addition, if you are led to the conclusion that somebody is an idiot, I presume you have a good reason—in particular, the invalidity of their argument. It is far more effective to explain what led you to this conclusion rather than to simply state the conclusion.

Stating a conclusion without explaining how you arrived at it makes it difficult to argue with, and any argument that attempts to purport itself as indisputably true seems to suggest fallacy to me.

  • 1
    Short and to the point. Great answer.
    – Peter
    Commented Apr 5, 2018 at 11:43
  • 9
    There are reasons one can have for mentioning their opinion that someone is an idiot other than ad hominem. For instance "You are an idiot, therefore there is no point trying to explain why you're wrong". Also, while "You are an idiot, therefore you are wrong" is an ad hominem, "You are wrong, therefore you are an idiot" is not. Commented Apr 5, 2018 at 19:29
  • 5
    @Acccumulation Not in a debate. If you say, "You are an idiot, therefore there is no point trying to explain why you are wrong," you are actually saying, "I declare that you are wrong, and my expressed belief that you are an idiot is the only proof I can offer." That is ad hominem, and your other example is exactly the same.
    – Daniel
    Commented Apr 6, 2018 at 19:43
  • 12
    @Daniel It is not "this is the only proof I can offer", it's "I don't feel like providing a proof". A fallacy is when one claims that an argument establishes one's position, when it doesn't. Simply refusing to present an argument is not a fallacy. Commented Apr 6, 2018 at 20:27
  • 2
    +1 I think that the answer would be more effective in reaching the people struggling with the asker's confusion if it was stated more in terms of people's perceptions of meaning rather than truth claims about asker's intended meaning. My specific suggestions would be: "you obviously have some point" -> "many people will think you have some point" and "which you implicitly do by sharing it" -> "which many people will interpret you implicitly claiming by sharing it".
    – mtraceur
    Commented Apr 6, 2018 at 21:12

In any communication, there is a context in which that communication is occurring. If they believe they are in a context of debate, and that your statement is intended to be part of the debate, then they are justified in declaring your statement to be an ad-hominem within that context. If you believe you are not engaging in a debate, and are instead merely blowing them off as a person because you don't like them, then you are justified in declaring that your statment is not an ad-hominem within that context. If people agree upon the context, they will agree on whether your statement is ad-hominem or not.

Personally, when I look at discussion A, without any additional context surrounding it, I see person B responding to person A's assertion, and the most likely interpretation I see is that person B is refuting person A's argument. Thus I see it as an ad-hominem attack.

If my interpretation is wrong, and person B was not trying to refute person A (perhaps person B simply spontaneously insults people for no reason), then it would be reasonable to say that person B was not engaging in an ad-hominem attack, but rather that they were simply failing to communicate effectively at all, because nobody besides themselves understood the meaning of their statement.

  • I agree with this 100%. Without further context, there is absolutely no difference between Discussion A and B. It is very reasonable to interpret the 2nd sentence in Discussion B as being implied from just the 1 sentence in Discussion A. Thereby making it a completely ad-hominem attack.
    – Dunk
    Commented Apr 5, 2018 at 17:14
  • 1
    I think as written this is the best answer in that it puts the most focus on the differences in mental framing that cause the same remark to be seen as either an fallacious argument or a venting non-argument.
    – mtraceur
    Commented Apr 6, 2018 at 21:16
  • 1
    This is definitely the best answer. The basic issue seems to be that the OP is intentionally making a statement outside the context of the debate; perspectives that fail to realize that the debate is a subset of the broader communication are flawed from the ground-up.
    – Nat
    Commented Apr 10, 2018 at 2:04
  • Yes this is the key to the issue. en.wikipedia.org/wiki/Relevance_theory: When you say something, people presume that you mean something worth saying, in the shared context, and will attempt to infer your purpose and implications. If person B ignores these conventions, person B fails to communicate.
    – LarsH
    Commented Apr 10, 2018 at 18:07

Basically, my question is, why do people assume that any insult is an ad-hominem fallacy, when, according to the definition, only certain insults are ad-hominem fallacies.

The simplest answer here is that people do not all assume that any insult is an instance of an ad-hominem fallacy, and those that do are sometimes mistaken. Firstly, an ad-hominem fallacy is not necessarily an insult. Rather, it is an attempt to use some characteristic of the person making an argument to disprove the argument itself.

For example:

A: Islam is a religion of peace.

B: Well, of course a Muslim would say that.

It is not insulting to acknowledge that speaker A is Muslim, but using their Muslim identity as a means of dismissing their argument is an example of an ad-hominem fallacy.

Perhaps your confusion is stemming from the fact that "ad-hominem" has two common usages? One refers to an ad-hominem attack, the other refers to an ad-hominem fallacy. The first usage is one that I have commonly seen online and it is essentially used to call out a person for being excessively insulting or personal. The second would refer to the technical definition of the ad-hominem fallacy.

Regardless, I would not concern myself too much with the parsing of what exactly constitutes which fallacy lest you fall prey to the fallacy fallacy.

  • 2
    Agreed, but generally it is insulting to imply that someone only has an opinion because they belong to a certain group.
    – Obie 2.0
    Commented Apr 5, 2018 at 8:45
  • 3
    In your example: "Islam is a religion of peace" is short for "Islam is a religion of peace, and you should believe this because I say so, and I am an honest, decent, reasonably intelliigent person who wouldn't lie about these things". "Well, of course a Muslim would say that" is short for "We would have to trust you on that, but as a muslim you would be more likely to not see faults in Islam than a non-muslim, which makes the statement weaker as if it came from a non-muslim".
    – gnasher729
    Commented Apr 5, 2018 at 9:55
  • 2
    You call it "ad-hominem fallacy", I call it conditional probability. Commented Apr 5, 2018 at 13:06
  • 9
    There's nothing wrong with parsing what constitutes a fallacy. On the contrary, it's a necessary part of evaluating an argument. Where the "fallacy fallacy" problem comes in is if you assume the conclusion is false only because the argument used to get there was fallacious. Evaluating an argument and determining that the argument is invalid (as opposed to determining that its conclusion is false) because the argument contains a fallacy is a perfectly valid thing to do. There's a difference between asserting "x doesn't prove y" and asserting "x doesn't prove y and, therefore, y is false."
    – reirab
    Commented Apr 5, 2018 at 14:48
  • 4
    @EricDuminil It's one thing to take additional circumstances into account when judging the veracity of a statement, it's another to use those additional circumstances to dismiss the statement entirely without due consideration. Most conditional probabilities aren't simply 1 or 0.
    – JAB
    Commented Apr 5, 2018 at 14:54

They're being kind.

Either your utterances actually advance the dialog so your ad hominem attack is an instance of ad hominem fallacy. Or you are a bloody idiot wasting everyone's time when you speak (in this way). I imagine if you keep doing the latter the kindness will eventually end.

  • But if the kindness ends and they just tell you directly that you're a bloody idiot wasting everyone's time, won't they be guilty of ad hominem? :P
    – Wildcard
    Commented Apr 6, 2018 at 0:59
  • @Wildcard : Yes. But by that time you will have established that you consider wasting everyone's time on such utterances is somehow justified by your valuation scheme, so you must treat such tellings as valuable. Commented Apr 6, 2018 at 1:40
  • That is absurdly circuitous logic. (Or illogic.) So you're claiming that utterances are valuable if (a) they are based on sound logical reasoning or (b) the recipient has a peculiar valuation scheme? I've encountered before the peculiar idea that every communication of opinion must (or should) be an effort to convince or persuade, which is utterly false just by simple inspection. And yet that idea seems to be the basis for all accusations of "ad hominem" made in informal dialog. How bizarrely self-righteous are the zealots of "proper" debate procedures....
    – Wildcard
    Commented Apr 6, 2018 at 2:07
  • @Wildcard : Nope. I'm claiming that a recipient doesn't get to complain when others respect the recipient's expressed value system. Commented Apr 6, 2018 at 2:12
  • That sounds like a very stuffy way to say, "you started it" as a total defense for insulting someone. And of course by continuing to claim something, it means you're still trying to debate with the person you suppose is not debating. And are looking at it in terms of "winning" an argument or debate. Whereas another "winning" move is to disengage, which is more effective in numerous other ways than attempting to press the point.
    – Wildcard
    Commented Apr 6, 2018 at 2:17

So why do people accuse me of committing a logical fallacy?

Because they have discovered that accusing another of a logical fallacy serves both to discredit that person, and to make the accuser look intelligent, and they have chosen to weaponize this knowledge. Whether or not the accusation is true or even applicable turns out to be immaterial.

  • 6
    No, it serves as shorthand to say "That is not a valid argument which you just presented, because you just tried to discredit my person instead of saying something that is relevant to the topic at hand". If you interpret getting your arguments getting shot down as "discrediting my person" and/or that shooting down your arguments makes the other person "look intelligent"... so be it. If you do not want to appear as a person that cannot carry themselves in a discussion, hold the insults...
    – MichaelK
    Commented Apr 5, 2018 at 7:59
  • 1
    +1 You make a good point. Calling something a fallacy could be a form of ad hominem attack itself. It shifts attention from the content of the discussion to focus on the form of the argument. Commented Apr 5, 2018 at 12:08
  • 1
    While this may be the case, we can only take the OPs words as they stand. And as they stand, that's all "discourse" we have. In the context given, both situations are indeed ad hominem, being the only reply to an argument. Whether accusing someone of committing a fallacy can itself be a fallacy is not the question. This does not (fully) answer the question in the OP and should rather be a comment on a possible aspect in the situation.
    – Philip Klöcking
    Commented Apr 5, 2018 at 12:41
  • 1
    Calling out a fallacy can not be taken as committing a fallacy, because it's not answering to an argument. You basically can't offer a counter-argument when someone has committed a fallacy since they didn't provide an argument in the first place. That's a perfect instance in which case saying "No, you're a bloody idiot" can't be construed as a fallacy.
    – BlindSp0t
    Commented Apr 5, 2018 at 13:04
  • 5
    Totally disagree with @FrankHubeny. Choosing to criticize the structure and logic of an argument isn't an ad hominem attack at all. You're not characterizing the person in any way, you're characterizing the logic of the argument. Commented Apr 5, 2018 at 13:05

It depends on the insult.

MichaelK already said it: If you try to infer that the argument of your opponent can be dismissed because of their character, then it is a clear argumentum ad hominem. Insults like "X is wrong because (!!) you are an idiot, imbecile, lunatic etc." are ad hominems, no discussion.

Because the dismissal has nothing to do with the argument itself, it can be also used before the argumentation begins at all: Poisoning the well. Before we argue about the merits of different methods against the population explosion, I want to point out that there are still child murderers under us who accept the torture and killing of unborn life. I hope there are no such people present, aren't they?

Now you can insult someone which does not exactly affect their logical position; I can call e.g. someone disparagingly a cheapskate without committing a logical fallacy. Being a cheapskate does not invalidate the argument nor does it implies missing argumentative skills. But it is what Schopenhauer in his creation The Art of Being Right: 38 Ways to Win an Argument calls Argumentum ad personam: They are not logical "ad hominems", but they can be used to lower social status and prevent people to agree with the person.

There are also other grey areas: If you call someone a liar, cheat, charlatan etc. because you can prove (!) that the person has no qualms about lying or pulling "facts" out of thin air...then from pure logic it is not a proof that the argument of the person is wrong.

A liar can still tell the truth if it suits him. A charlatan may believe that his concoction has real healing effects.

But, and this a big but, having limited lifetime and knowing that someone is dishonest, we sooner or later pull out of the "discussion". For having a discussion we need to have at least the possibility that our opponent can teach us something. A fabricated fact, a "dog eat my sources" and knowing well that an argument is invalid, but using it again and again, can invalidate a person for discussion, even if it is logically insupportable.

Another grey area is bias: If we are presented with a supposedly unbiased "expert" and someone finds out the "expert" has in reality very clear bias (e.g. member of a partisan think-tank and the person is paid for his presence), pointing out the connection is also often accepted. "He who pays the piper calls the tune."

In both grey areas of liars and biased people you can logically argue that these are strictly "ad hominems" if you point them out because it does not address the arguments brought forward, but from experience it is important information because it negates trust which is a key point for a fair discussion.


tl;dr- You're right, this is a common misunderstanding. While perhaps not particularly mature, calling someone a "bloody idiot" can be a comment outside of the context of a debate. Rather than being a fallacy or non-fallacy, such a statement doesn't exist within the context of the debate at all.

Within the context of the debate, it's essentially a non-statement. As discussed in @CortAmmon's answer, this contextual confusion.

Analogy: Multiplexing serial communications

Most computers can be said to have a single serial port through which they access the internet. All of the data that comes in is like a stream of 0's and 1's, then gets streamed to various endpoints through multiplexing:


The above multiplexer description is flat, though in practice multiplexing tends to be a hierarchical process. Anyway, details aside, it's then important for the communication protocol to sort incoming data into the various endpoints that ought to receive it.

With computers, multiplexing tends to require precise framing. Part of this is that ambiguities can be exploited, allowing hackers to get undesired effects:


With humans, our language tends to be far less precise, so while we must still multiplex our communications, the routing process involves a lot more inference.

As given in the question statement, Person B doesn't intend for the string "You're a bloody idiot." to be parsed within the context of the argument. Since that string should never be routed to the argument in the first place, it has no existence within the argument; it's neither a fallacy nor a non-fallacy.

At most, Person A can say (in awkwardly precise language):

I've interpreted your prior message as being within the context of our debate, though I have not found a non-fallacious interpretation of it, such that I believe that your thinking is in error. Specifically, I believe that your assertion that I'm a "bloody idiot" has some bearing on the issue being discussed, which is an error (fallacy) on your part.

But to be more concise, they might simply say:

That's a fallacy.

I suppose that a correct response might be to say:

No, I wasn't continuing the debate. I'm making a comment outside the context of the debate in which I'm expressing my belief that you're a bloody idiot. By this, I mean [elaboration].

Or to be more concise (if not a bit terse):

No, I wasn't arguing with you; I'm just calling you an idiot.

Not to say that this is polite or acceptable in moderated venues, e.g. on StackExchange, however it'd be logically correct.

On moderated venues, it may simply be easier to stop responding. This also has drawbacks in cases due to the public nature of such forums, though I guess various constraints limit how much can be effectively communicated anyway.

Detail on the multiplexing analogy

Revisiting this answer, I'm not sure how obvious my multiplexing analogy may've been, so this section is meant to explain it a bit.

The basic point is that a "fallacy" is an invalid construction within a debate:

A fallacy is the use of invalid or otherwise faulty reasoning, or "wrong moves" in the construction of an argument.

-"Fallacy", Wikipedia [references and formatting omitted]

So, obviously, something must exist within a debate to be a fallacy within it. For example, someone can turn on a TV, but if that's not part of a debate, it can't be a fallacy or non-fallacy within it.

The main point of this post is that folks might be confused due to the assumption that all words in an exchange in which a debate occurs are necessarily part of the debate. But, that's the basic mistake.

Instead, people can exchange words, including having one-or-more debates, without all words being part of all of the on-going dialogs. This is like how a computer can play music from the internet while a user is checking their email; the email app and music app are both streaming info over the same serial line, but the music doesn't exist in the email app nor do the emails exist in the music app.

  • Another example could be person A asking person B "what's up?" and person B responding with meticulous account of what is, in fact, up. It is usually not indended to be parsed this way, more like "I express friendly attitude towards you" - which is an important part of healthy day-to-day communication, but in context of this site this would simply be considered noise. Commented Apr 10, 2018 at 10:23
  • Although the question arises if it really happens that the "bloody idiot" opinion just arose during an argument independently of the argument. In virtually all cases, "you are an idiot" does not come out of the blue while being in an argument, but is very much related to the argument itself. In theory, people might think and say something like "I think your logic on this point is incorrect, and by the way, on a completely unrelated thought I think you are an idiot for reasons independent of this topic, but lets return to the discussion where I will prove why you are wrong." But not in reality.
    – Thern
    Commented Apr 12, 2018 at 10:08
  • @Thern I'd also assume that the "bloody idiot" comment is almost certainly a consequence of the argument. Just, while the comment was a function of the argument, it doesn't exist within the argument. Like in the analogy about multiplexing, if two people are playing a video game online and get mad at each other, they might start yelling at each other the next day at work or something; however, their anger, while a result of the video game, isn't within the video game. Within the scope of the video game (or, let's say, chess game), their argument isn't a valid or invalid move.
    – Nat
    Commented Apr 12, 2018 at 10:12
  • @Thern Actually, lemme select an online chess game for that example. Then what I mean is, while the chess players might get mad at each other, their anger and consequential actions aren't invalid moves within the chess game; the chess game remains intact so long as its rules are respected. It doesn't become invalid just because other things are happening outside of it.
    – Nat
    Commented Apr 12, 2018 at 10:14

One could view calling someone a “bloody idiot” as rhetorical satire rather than a fallacy. See this discussion of “Satire in Rhetoric”: However, as that article mentions such satire could succeed as an “effective rhetorical tool” or it could be “misconstrued as offensive to certain audiences depending on the topic and the situation”.

That your rhetorical efforts received objections and were described as a logical fallacy suggests that the audience was not amused, and most importantly, that they were not convinced. If that was the case, and assuming you were truly interested in convincing the audience of some position and not just engaging in verbal abuse, it would be advisable to try an alternate rhetorical approach besides satire.


It's only a fallacy if you're basing an argument off of that insult that intends to be logical and free from flaws. Some ad hominens might not be fallacious in arguments about someone's character and morals, but it's easy to get caught up in the wrong details that way. At the very least ad hominens are poor form because they include extraneous information. For example, "Jill is a patsy, and patsies are weak, this is why patsies are weak, this is why Jill is a patsy, therefore Jill should not be expected to be strong" really doesn't benefit from calling Jill a patsy at all. The argument would be more concise if you just asserted that Jill is a weak individual and should not be expected to be strong. Calling Jill a patsy is just being needlessly mean.

Another thing to watch out for with this sort of thinking is that fallacy fallacy. You can't discredit someone's conclusion because their argument is fallacious. For example, 1+2 = 1+1+1+1 = 3. Here the sum of 1 and 2 is not equal to the sum of 4 1's, but it is equal to 3. When someone accuses you of using a fallacious argument keep in mind that they're attacking your logic and not your premise or conclusion. It's bad form to dismiss someone because they use ad hominens or because they've brought up something that's not related to the discussion. That's just an excuse to leave a discussion.

Another thing to realize is that debates usually aren't won with logic, but with ability to appeal to humans. If you're trying to win a debate instead of having a discussion then using a bunch a fallacious arguments well is going to give you a large advantage. This will piss off whoever you're talking to though. This is why sick burns end so many "discussions" on the internet.


why do people assume that any insult is an ad-hominem fallacy, when, according to the definition, only certain insults are ad-hominem fallacies.

Because those people do not understand the ad-hominem fallacy.

Person A: Smoking is healthy because my doctor says so.

Person B: You're a bloody idiot.

As long as that is the only reply of Person B, this is a valid example of the "ad-hominem fallacy", because Person B "avoids the genuine discussion of the topic at hand by instead attacking the character".

It's the avoidance of a discussion that makes it a fallacy, not a usage as an argument.

In logic, this is a fallacy because avoiding the discussion does not help in getting closer to the truth of a matter. Anything that stands in the way of truth is a fallacy. This is following the broader definition of fallacy, not the more narrower definition of logical or formal fallacies.

Here is an insult that is not the ad-hominem fallacy:

Person A: Smoking is healthy because my doctor says so.

Person B: You're a bloody idiot, but I see your point. Explain more why smoking is relevant to your health.

If you consider the statement "You're a bloody idiot" as a factual statement, not an insult (maybe they do have the idiot certification you talk about and are covered in blood), then this could be a red herring fallacy instead of the ad hominem fallacy. An attempt to redirect the argument to another topic. That would be similar as to this discussion:

Person A: Smoking is healthy because my doctor says so.

Person B: Drinking turns wine into water.

But really "You're a bloody idiot." is an insult, not a mere deflection to talk about a different topic.

  • 3
    Which "point" does Person B see? What if Person A really is a certified idiot? Commented Apr 5, 2018 at 13:08
  • 1
    @EricDuminil Even if they're a certified idiot, it doesn't have any bearing on the correctness of their statement directly. In the same sense, using an ad hominem doesn't mean that the person using the fallacy is wrong. They just are not arguing the point in a logical way. A certified idiot can still be correct, just like someone using logical fallacies may still reach the correct conclusion .
    – JMac
    Commented Apr 5, 2018 at 14:36
  • By your logic, "You may be right, but I'd rather not talk about it" would be a fallacy, since it avoids discussion. What makes a statement fallacious is that is that it is made with the intention (or supposed intention) of proving an argument, but even if true it would do nothing to support the argument in question. If someone says "I measured the length of the __ as __" and someone replies "That's because you're too cheap to get a good ruler", there is an implication that the former person's ruler might be inaccurate, and if the ruler does happen to be inaccurate any measurements...
    – supercat
    Commented Apr 6, 2018 at 22:41
  • ...using it may be inaccurate as well. The ruler might happen to be accurate, but if it is particularly that may be reason to doubt its reliability unless or until it is verified. On the other hand, if someone says "__ just turned 50 last week" and someone replies "That's because you're too cheap to buy a good ruler", that would be an ad hominem fallacy because the quality of a person's measuring stick would have no logical relationship to whether __ turned 50 last week.
    – supercat
    Commented Apr 6, 2018 at 22:45
  • You are arguing the meaning of the word "fallacy". If you look e.g. at wikipedia, you will see that it defines a multititude of fallacies, not all of which are formal/logical fallacies. I am not saying wikipedia is right, just that it is a waste of time to discuss which of the multiple known usages of "fallacy" is the true one.
    – tkruse
    Commented Apr 9, 2018 at 0:31

I don't think you have properly separated what you say from what happens to be the case. In your example, when Person B insults Person A at Discussion A, it is not clear that Person B knows the truth that smoking is bad for your health.

The insult could have been leveled for any variety of reasons (such as having a toffish accent). Thus, if we as enlightened critics say that the insult at Discussion A was a fallacy, we're not wrong just because the insult's predicate was daft: it's wrong to think that ad-hominem progresses a words-based argument forward or backward.

Now if an argument is based on a person's character, as when a person testifies about something that they know (as in court), the ad-hominem you level at them does progress the argument: "Don't listen to him, he's a crook."


An ad hominem argument is not a simple insult and there are various types. Guilt by association is one. For example, X says that the state should help poor people. Y says that X is friendly with communists. Y concludes that X and his views are questionable. This argument is ad hominem and invalid. The primary purpose of the invalid argument is to discredit the speaker, not to insult.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .