logical fallacies

[factor-fiction]

Many of us on AB recently learnt that IDOLA means 'logical fallacies'- but can anyone give an example of a 'logical fallacy' ?

[beckersjay]

All cats have whiskers. My grandfather has whiskers therefore my grandfather is a cat.

[Quizmonster]

Click http://en.wikipedia.org/wiki/Fallacy for a whole raft of examples of the different forms of logical fallacy.

[factor-fiction]

Thanks Quizmonster. I've had a quick read of that, particularly the sections on Deductive Fallacies and Other Systems of Classification. I have two queries:

1. Under Deductive Fallacies, the article includes the following :

• "In philosophy, the term logical fallacy properly refers to a formal fallacy: a flaw in the structure of a deductive argument which renders the argument invalid. However, it is often used more generally in informal discourse to mean an argument which is problematic for any reason, and thus encompasses informal fallacies as well as formal fallacies.

So, if the term 'logical fallacies' can include formal and informal fallacies, does this mean that all fallacies are logical fallacies and therefore the word 'logical' is superfluous?

2. In the section on Other Classifications I see that it was Bacon who used the term IDOLA. The article says:

• "Of other classifications of fallacies in general the most famous are those of Francis Bacon and J. S. Mill. Bacon (Novum Organum, Aph. 33, 38 sqq.) divided fallacies into four Idola (Idols, i.e. False Appearances), which summarize the various kinds of mistakes to which the human intellect is prone."

Again, does this mean that IDOLA means any type of fallacy, not just Logical Fallacies?

[Quizmonster]

To some extent the word, logical, IS superfluous, as you suggest; however, philosophers - like most professionals - are less than kindly towards any tampering with their own jargon!
The Oxford English Dictionary defines idolum - the singular form - in this sense as (quote) "a false mental image or conception; a fallacy." It would seem fair, therefore, to say that it may be used of ANY fallacy. One of the dictionary's illustrations from around the time of Bacon says that idola are (quote) "the profoundest fallacies in the mind of man," so there is another more general definition.

[factor-fiction]

Thanks Quizmonster and beckersjay. This thread didn't exactly attract much interest but I suspect most ABers have had enough of questions about Logical Fallacies after the spate of questions from 1-2 weeks ago.
Maybe an example of a logical fallacy is that "by putting a search box on AB users will use it".
Or maybe that point is a logical fallacy in itself, for although we do see repeated questions we never get to know how many users are successfully using the tool to get answers.

[Quizmonster]

Factor, your last response has reminded me of something I have long believed about questions on AnswerBank; namely, that they are - in another reference to Bacon - "hostages to fortune".
Bacon was referring to wives and children, but queries here are in a similar position in that the questioner has no idea just WHAT is going to happen to them!