AD IGNORANTIUM: Considered a flaw in reasoning, an ad ignorantium argument appeals to ignorance, as it were. One commits this error if, after failing to find evidence that a claim is true, one appeals to ignorance by concluding the claim is false, or vice versa: There is no evidence of X (or -X). Therefore, -X (or X).
On another board I occasionally visit, there was a huge discussion and series of arguments about the existence of God. The discussion, I believe, was mostly respectful of people's beliefs whether they were believers or not.
Anyway, one of the series of arguments was that something could be held to be true unless proven to be false. And that series of arguments bothered me.
Tonight I was reading an online lexicon and came across arguments 'ad ignorantium' and really liked the definition I posted above. It seems that this covers my problem with those who argued on the other board that one cannot argue against the existence of God without proving that God does not exist. I thought: Well, just to say that God must exist because the other side cannot prove that God doesn't exist doesn't make sense either.
I mention this, not to pull us into arguments for or against the existence of God--especially since this board avoids discussions of religion--but to ask whether the 'ad ignorantium arguments' are fallacious in this case because an argument for or against has been proposed without evidence either way. In other words, without evidence for or against the existence of God, God's existence cannot be proven or disproven, and any arguments without evidence either way would be instances of arguments ad ignorantium.
Have I correctly grasped this concept of 'ad ignorantium' or not?
Thanks for any insights.
The way I read the definition, WW, was something like this (and we'll take something slightly less contentious than the existence of God).
Supposing you have read somewhere that somebody has a theory that the Pyramids were built by aliens. I tell you this is nonsense and give various reasons why I think this is extremely unlikely. You are not convinced by my arguments (perhaps because neither of us really knows very much about Egyptology) and therefore conclude that the Pyramids were built by aliens.
It is akin to the mis-step in some people's logic that proving that it is possible that something happened is equivalent to proving that it did happen. For example, someone might argue that it is possible a Roman ship got blown off course and ended up in Central America, and then go on to assume without any proof that this did in fact happen. It is a method of argument that is distressingly frequent, but I have no idea whether there is a special name for this fallacy. If anyone knows perhaps they could tell us.
Bingley
Dear Bingley: I saw something on the Internet about artefacts being discovered in South America that are believed to have been of Mediterranean origin.
And speaking of the Pyramids, a French expert on geopolymers has written a book giving what I consider quite believable arguments that the blocks of the facing of the Pyramids were not cut and shaped before installation, but were cast in place. If interested, search for Davidovitz, Riddle of the Pyramids. I'll got check that and post URL.
Here's the title of his book:
- out of print - First edition: The Pyramids, An Enigma Solved
by Joseph Davidovits and Margie Morris
ISBN 0-87052-559-X Hippocrene Books, New York 1988
ISBN 0-88029-555-4 Dorset Press, New York 1990)
one cannot argue against the existence of [the invisible pink unicorn] without proving that [the invisible pink unicorn] does not exist.
While this is true, it is also true that an inability to disprove the existence of the invisible pink unicorn is not proof that the invisible pink unicorn *does exist and *that is the argument ad ignorantium. And, yes, it is a fallacy.
In reply to:
that is the argument ad ignorantium.
It's evidence that's the thing, yes?
Without evidence either proving or disproving, both sides of the arguments would be arguments ad ignorantium.
And this is such an interesting situation to consider. I agree with Bingley that these kinds of arguments are made too often. And, Faldage, I'm reminded of my own incorrect proposition about down's being an interjection--and you said I couldn't say that it was so simply because I said it was so. Mine was an instance, wasn't it (without formally arguing) of an argument ad ignorantium? Or at least a proposition ad ignorantium. However, I think propositions might be casually taken to be arguments, yes?
But your point: You can't say something is simply because you say it is gets at the heart of the ad ignorantium argument.
It's all about evidence.
This year in English 9 I'm pretty much overwhelmed by the number of literary terms and vocabulary I have to teach, not to mention the numerous grammar concepts to introduce and/or reinforce.
But next year I really am going to have important fallacies studied--even if we just cover one a grading period. The post hoc ergo propter hoc will be one, and I think this ad ignorantium would make a very good second one. Two to go before next year!
The nice thing about learning these fallacies is that you can challenge the students to listen to the news and political speeches and play Spot the Fallacy. And they'll be inundated by them, from the left, from the right and even from the extreme middle.
Dear Wordwind
As I understood it, the argument from ignorance (I'm more comfortable with the English), goes something like:
"You can't prove that there are no ghosts. You don't know it. So you can't tell me there are no ghosts. I've felt them in Bodiam Castle, so there."
The argument you speak of seems to be something like an argument from authority (also considered a logical fallacy), except that you are using yourself as the authority you cite! lol!
More commonly, the argument from authority might go like this: "We know that evolution took place through natural selection because Darwin says so." (It may be true that evolution took place through natural selection, but Darwin's saying so doesn't make it more or less likely. Darwin's arguments, on the other hand, as opposed to his assertions, may still hold water with us, but that is a different matter.
cheer
the sunshine warrior
It seems arguing from authority v. arguing based on the opposing side's ignorance are similar, but different.
The difference is no authority is mentioned in the ad ignorantium argument. By virtue of the fact that the opponent can cite no evidence, you claim that your position is true. I win because you can't prove your point.
In searching the web to learn more about ad ignorantium arguments, I realized that much of what is thrown at us as being true is based on the fact that the opposition didn't have evidence enough to support their thesis. Well, I must be right if you can't provide a shread of evidence to show that the your point is valid.
What is the latinate term for proposing arguments based on authority? I do remember coming across that term as another example of fallacious argument.
After you study these fallacies for a short while, you do begin to realize that there's a mountain of fallacious arguments out there--just as Faldage wrote about above.
I'm not well enough acquainted with all the fallacies to know which one best fits your example. You might check out this page:
A List Of Fallacious Arguments
http://www.cs.colorado.edu/~lindsay/skeptic/arguments.html
Thanks very much, gh. The site looks promising--I gave it a quick glance, saw arguing from authority and arguing from false authority along with arguing out of laziness! Ha!
Max, if you look in here, do take a look at gift horse's link--don't know whether you have that one, but it looks promising.
I like it. It doesn't look familiar.
Thank for the sugestion, WW, and for the excellent link, gift horse. I now know why I am glad some of my drapes don't reach the floor.
There's not a lot of difference between ad ignorantium and begging the question. But then, there isn't a lot of difference between quite a lot of approaches to fallacy!