« Why Throwing Shoes Isn't Free Expression | Main | Free Speech - Talk in Keswick - Words by the Water Literary Festival »

December 16, 2008


Julian Baggini

Nigel, it's an analogy, and although imperfect, it generally holds. It was not said as a logical principle.
In the book I say:
"Actually, I don’t think I am immune to the mistakes I have catalogued here. I may even have made a few of them (or others) in these very pages. That is not a fatalistic admission that none of us can ever be more rational or consistent than any other. It is rather a reminder that the pursuit of noble ends, such as truth or goodness, is difficult and bound to be accompanied by error. However, when one puts oneself on the side of the angels it is all too easy to start believing that one has sprouted wings."
I also talk about "trained philosophers, who grow to assume that they have critical thinking skills denied to the rest of the world, but then fail to use them correctly. They sometimes commit what I’d call the 'fallacy fallacy': believing that because they can identify the form of a logical mistake in an argument, they can therefore dismiss it out of hand."
That's not quite what you've done here, but do remember that The Principle of Charity is an important part of the critical thinking toolbox!

nigel warburton

Thanks for replying Julian. Your sausage making analogy as presented here suggests this: put in good premises and you get good sausages (i.e. true conclusions) out. So far so good. A valid argument is truth-preserving. So here you have described a sound argument (i.e. valid with true premises and so a true conclusion). But you also say that if you put bad sausages in you are likely to get rubbish out (i.e. false conclusions). This isn't correct. The point is that you may or may not get rubbish. Nor do you know the probability of getting rubbish out from the fact that you put rubbish in. You often get true conclusions from false premises using valid argument forms.

Socrates was a fish (bad sausage meat)
All fish have been in the Brazilian football team (bad sausage meat)
Therefore Socrates was in the Brazillian football team (good sausage)

In relation to what you call the 'fallacy fallacy' (which may itself be a fallacy) you might like to read the section 'that's a fallacy' (p.143 -44) in my Thinking from A to Z (3rd ed.) - falsely accusing someone of committing a fallacy (or in this case hinting that they have done, but then backing off a bit) as a type of rhetoric.

Also, my entry on the principle of charity in the same book - including reservations about its use in some circumstances (see p.35).

Gareth Chantler

It is funny that Nigel seems to be holding to Julian's characterization of philosophers...but let's not take this characterization too far lest we want to silence criticism. There are so many examples of putting in bad info and logic and getting the right answer -- problems of limited choices being the most striking. An easy example can be found in true/false or multiple choice tests.

More interesting examples comes in game theory, take poker for instance. Say you are playing against one other person and they put all their chips in the middle with no cards to come -- so your choice is to call or fold. You have a medium strength hand -- you can beat a bluff but nothing else. Your opponent has made some faulty assumptions about you: notably that you are a good player. In other words the story the opponent told you throughout the hand would be deciphered by a good player as reason to fold your hand. But you aren't a good player -- and you miss the cues good players pick up on -- and instead focus on irrelevant cues. You notice something in your opponent's demeanour, he looks nervous to you because he has clasped his hands. You make the call based on this and win the hand. Whereas a good player might make the wrong decision based on the right information a bad player often makes the right decision based on terrible logic and faulty information. This actually happens all the time in poker and one of the reasons is the limited choices available: call or fold.

Nigel gave a good example of a syllogism for bad input and good output, but game theory might give us more interesting ones. When the first level is equal to the third level, a thinker only capable of first level thinking may get right what a second level capable thinker would get wrong.

A hasty example:
1st level thinker: he's bluffing because he didn't bluff the last time = call
2nd level thinker: he's not bluffing because he didn't bluff the last time and thinks that I will think on level 1 = fold
3rd level thinker: he's bluffing because he didn't bluff the last time and thinks that I will think on level 2 (which was what the opponent actually was thinking) = call

Bob Churchill

More importantly, if the argument is valid, then whether the sausage meat is good or bad, you have to remember that it's still the same sausage meat that comes out the other end.

As John Stuart Mill pointed out, all valid deductive arguments suffer from content diminution - you have to assume content which "contains" the conclusions you end up concluding or the argument isn't valid. In other words, all deduction begs the question. Even in the case of a Reductio, although you haven't assumed exactly what you end up concluding, the eventual negation of one of your premisses is still implied by your premises.

This doesn't mean logical argument is useless, it can be used critically, in the case of a reductio, to show at least that a given set of premisses cannot be sustained as a set, and obviously a deduction can elucidate that which was only implicit before. But that's a psychological gain. What a deductive argument can never do is confer support to its conclusion. That's one of the great myths of what W. W. Bartley called Justificationism, and that it is a myth still hasn't sunk in for most philosophers. A valid deductive argument can no more "support" or "justify" a logical conclusion, than wearing a badge that says "Everything I say is true" can warrant your political or moral conclusions.

nigel warburton

Thanks very much for this useful and interesting comment, Bob.

I think we are near the point where the sausage meat image breaks down here unless we think that re-combined bits of bad sausage meat can somehow produce good meat.


Now I'm only a student of philosophy, but it strikes me that characterising the value of deductive arguments as "psychological gain" seems to belittle their contribution to one's life.

In addition to throwing up inconsistent beliefs (as discussed before), I would like to add that sound arguments can also highlight conclusions that do not seem obvious at first glace, but that are not absurd at all.

This is useful, to me at least, because I am not a deduction engine, and I am not constantly engaged in the act of reasoning about what follows from the mass of beliefs that I already hold.

So I appreciate it when I come across something which I entirely agree with, but which did not occur to me before. While this may not produce Knowledge with a capital K, it is news to me.

Like this bit of Aristotle I am reading: "If the virtues are concerned with actions and feelings, and if every feeling and every action is always accompanied by pleasure or pain, on this ground too virtue will be concerned with pleasures or pains."

The comments to this entry are closed.

My Photo

Get Virtual Philosopher by email...

Enter your email address:

Delivered by FeedBurner

My Podcasts

My Art and Photography Weblog

Philosophy: The Classics

Philosophy Bites

Ethics Bites