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• Logic issues

  ReneZ > 26-04-2020, 07:21 AM

  When reading in papers, blog posts, forum contributions related to the Voynich MS, I regularly run into issues with the logic applied. Sometimes these are obvious, but sometimes they are not, and the logic works like a smoke screen that does not allow us to see clearly. I am sure that in many cases this is not even intentional.
  
  I don't want to start the 'complete list of logical errors' here, but there are a few typical cases that stand out.
  
  In a recent Spanish paper, I once again encountered the problem where weak evidence is used to negate strong evidence. A typical issue is that evidence is not weighted on its objective strength, but on whether it is favourable or unfavourable to one's thoughts.
  
  Another common error is the non-sequitur. A conclusion simply does not follow from the evidence provided. Even when it may seem quite logical at first sight.
  
  The case that I keep running into I would like to call 'proof by example'. It may have a proper name, but I don't know it. It is related to 'disproof by counter-example'.  Both may be valid in some cases, but are not valid in many other cases.
  
  If one wants to prove that something is possible, then giving an example is sufficient of course.
  However, let me illustrate the problem with an easy example.
  
  Suppose I hold a fruit behind my back and I ask someone to guess what it is, and I tell him that the fruit is yellow. The answer could be: it has to be a lemon, because a lemon is yellow. This is what I would call 'proof by example'. It is obviously not valid, because it could also be a banana. 
  It is not sufficient to argue about the likelihood of the two cases, because there are even more yellow fruit, some which the guesser is not even familiar with.
  
  If I gave additional hints, they would only work if they actually distinguish between the two.
  
  Someone else might guess: "it is an orange". When I argue that oranges are not yellow, he could say: they are. Here, the perception of the guesser is blurred. It may seem as if I am making a strange point, but this sort of thing is happening all the time.
  Since much of the discussions are quite subjective, it is rarely as easy as in this example.
  
  I also could hold a red fruit behind my back, and suggest to the guesser that it is a banana. The guesser would say: no it can't be because bananas are yellow. Well, red bananas exist, so this is a case of incorrect disproof. This also happens all the time.
  
  
  The Spanish paper I mentioned in the beginning considered:
  - the Meso-american herb identifications
  - the identification of a meso-american language by Hauer and Kondrak
  strong evidence, much stronger than the radio-carbon dating of the paper (sic) of the MS.

• RE: Logic issues

  -JKP- > 26-04-2020, 09:34 AM

  There is also the problem of cherry-picking examples to fit the theory.
  
  

  • In the Tucker and Janick book, for example, they chose a photo of a plant that looks quite a bit like a plant drawing in the small-plants section of the VMS. But... it is an atypical photo of that plant (almost a mutant version). The plant is normally a different color and shape and I have never seen one as odd as the one in the picture they used, so it is probably not a common variation. There is always a risk in choosing atypical examples as "proof" of an idea.
    
  • In the same book, there is a plant ID for a plant that cannot grow in Meso-America. It's very habitat-sensitive to heat and humidity and has a very narrow range in a small region of California. It is very unlikely that it ever grew in the area they pinpointed for the VMS origin.
    

• RE: Logic issues

  ReneZ > 26-04-2020, 11:30 AM

  These books and the preceding work carry plenty of examples of what I was trying to illustrate.
  
  Just showing that a certain plant looks like a meso-american species is like the lemon in my example.
  There are European species that look equally similar, so there's the banana.
  
  The two problems are:
  - "looks like" is subjective
  - one is too easily biased to prefer evidence that is in favour of one's theory

• RE: Logic issues

  ReneZ > 26-04-2020, 12:41 PM

  With respect to the problem of "non sequitur", the elementary form of deduction could be described as:
  
  "A" therefore "B"
  
  We have a piece of information "A", and from this we deduce "B".
  
  Now this can go wrong in several ways. "Non sequitur" means that A can be true, but B does not follow from it. The basis of most arguments presented in favour of the "modern fake" theory is like this.
  The argument is that:
  "A" is the observation that something is unusual
  "B" is the conclusion that the MS is a fake (or more likely to be a fake).
  This does not follow.
  
  But the deduction can go wrong in other ways.
  It could be that "A" is not true in the first place.
  
  It could also be that "A" is not known, but an assumption or a hypothesis. As soon as "B" has been derived from it, this important distinction is lost.
  In reality, "A" and "B" become part of the same hypothesis, and they don't provide evidence that this hypothesis is likely to be correct. They don't confirm or support each other. This quickly leads to circular reasoning.
  
  A remarkable example of this is a book that links the Voynich MS with the Italian 'Castel del Monte' by Fallacara and Occhinegro. Their theory is that this castle was once a "temple of health".
  Towards the Voynich MS community, the suggestion that this castle was such a place was presented as evidence that this castle can be seen in the Voynich MS on f85r2.
  Towards the italian historic community, its appearance in the Voynich MS was used as evidence that this castle was used for such purposes.

• RE: Logic issues

  Antonio García Jiménez > 26-04-2020, 01:26 PM

  I agree with you René. I almost always agree with what you write. In the examples you put, more than logic I see a lack of common sense. For me the Tucker and Janick book it's a monument to a lack of common sense.
    
  But speaking of logic, since I entered the forum I have been saying what is my deepest conviction about the VM: that we use reasoning and analysis methods that are not valid for this genuine cultural object.The greatest proof that it is an authentic document is that a forger would have made the same mistakes as us when trying to decipher it: He would have tried to hoax with a more o less understandable meaning.
    
   The weird imagery and the weird script of the VM allude to hidden powers, natural magic, one of the medieval sciences. I believe that without this perspective the VM cannot be understood. Therefore it is a magical logic that must come into consideration. The script is governed by rigid rules but its meaning does not respond to our logic.

• RE: Logic issues

  bi3mw > 26-04-2020, 01:52 PM

  (26-04-2020, 12:41 PM)ReneZ Wrote: You are not allowed to view links. Register or Login to view.Now this can go wrong in several ways. "Non sequitur" means that A can be true, but B does not follow from it.

  A good representation of an argumentation 'non sequitur' is that in the German Wikipedia:
  
                           When I'm in Vienna, I'm in Austria.
                            I'm not in Vienna.
                            -----------------------------------
  'non sequitur'      That's why I'm not in Austria.
  
  Even if both premises apply, the conclusion is not correct, because I could be in another place in Austria (outside Vienna). This example is an incorrectly applied contraposition. Misconstructions of this kind are experienced again and again in Voynich research (and elsewhere, of course). Even if two or more statements are true, the conclusion can still be wrong.In any case it is helpful to check hypotheses for logical errors of this kind.
  
  
  Edit: Even an additional listing of other cities in Austria would of course not change the fundamental error, the argumentation would not improve.

• RE: Logic issues

  R. Sale > 26-04-2020, 07:51 PM

  Rene said:
  "A" therefore "B"
  
  We have a piece of information "A", and from this we deduce "B".
  
  **
  
  It is convenient to consider this to be a straight-forward and fairly singular process. It's nice to think that 'therefore' is an unbiased attempt to discover 'truth' based on fact. Ideally things might work that way, but this is the VMs. Not only the process and naturally the product now have become moving parts. It is also necessary to go back and reconsider the initial substance that constitutes the original input. Essentially it's the old saying: Garbage in, garbage out. And this is particularly true in the investigations of the VMs, because of it's 'ambiguous' appearance.
  
  What can be done? It is necessary to base interpretation on a valid external standard from an independent source. One possible source is the record of medieval tradition. However the problem with this is that various elements of traditional interpretation well-known in that earlier era have essentially been lost for much of the VMs investigative history.  The traditions have become obscure, their representations in the VMs are idiosyncratic at the least, if not intentionally obfuscated as well, and the connections to tradition have not been made.
  
  A simple example of this is the recovery of traditional terminology to name the nebuly line. The tradition is based on heraldry. The descriptive term, whether 'nebuly' from Latin or 'gewolkt' from German, has an etymology that indicates a cloud-based derivation. But without the proper terminology, if something cannot be properly named, then it can not be properly interpreted. The whole "A" therefore "B" thing falls apart, and can't get off the ground, if "A" cannot be properly identified. This failure makes for a lot of GIGO.
  
  To demonstrate the validity of the traditional interpretation: nebuly line = cloud band = cosmic boundary, some of the best examples are in the Berry  Apocalypse of c. 1415. Interesting, moreover, that this book and the c. 1410 version of Oresme (BNF Fr. 565) both started off in the possession of the same person, Jean, Duke of Berry (d. 1416, Paris).
  
  Furthermore there is the potential for discovery of a higher level of organization with the accumulation of data from different investigations.
  In one scenario we may have: "A" therefore "B"; "C" therefore "D"; and "E" therefore "F" etc.
  In a second scenario we may have: "L" therefore "X"; "M" therefore "X"; and "N" therefore "X".
  What does logic indicate then?

• RE: Logic issues

  ReneZ > 26-04-2020, 08:17 PM

  Surely, if "A" therefore "B" gives rise to complications, then: "A" and "B" and possibly "C" therefore "D" and perhaps "E" will be much worse.
  
  Deriving conclusions from the similarity of a particular drawing the Voynich MS with a drawing in another manuscript is a typical example of the lemon/banana problem. There may be lots of other drawings in other manuscripts that are equally similar, and it is also possible that the similarity is coincidental. After all, the basic patterns included in it are fairly standard.
  
  Also, in the case of the Oresme cosmos, the spirals are missing, and these are perhaps the most conspicuous part of the Voynich MS illustration.
  
  It's a draw, in my view.

• RE: Logic issues

  -JKP- > 26-04-2020, 08:37 PM

  (26-04-2020, 08:17 PM)ReneZ Wrote: You are not allowed to view links. Register or Login to view.
  Surely, if "A" therefore "B" gives rise to complications, then: "A" and "B" and possibly "C" therefore "D" and perhaps "E" will be much worse.
  
  Deriving conclusions from the similarity of a particular drawing the Voynich MS with a drawing in another manuscript is a typical example of the lemon/banana problem. There may be lots of other drawings in other manuscripts that are equally similar, and it is also possible that the similarity is coincidental. After all, the basic patterns included in it are fairly standard.
  
  ...

  
  
  This is EXACTLY why it takes me so long to write blogs, why it takes me so long to post research I did years and years ago.
  
  You find something that looks similar. For example, John Watson, the palaeographer, declared that he was very sure that the foliation was in the handwriting of John Dee. It IS very similar handwriting.
  
  But I am always suspicious of things that are similar if I have not looked around to see if there are OTHER things that are equally similar (or moreso). And guess what. Over the course of 10 years I found a few examples of handwriting that were equally similar and some that might be more so. It takes a long time to confirm or deny similarity.
  
  
  I really wasn't comfortable talking about the VMS zodiac figures until I had collected about 500 hundred examples of complete zodiac cycles. I honestly didn't feel that 20 or 50 or even 300 was enough to make any kinds of generalizations about them. Now I have about 700, about 620 or so that are complete. It is reaching my comfort zone. I would be even happier if I had 800 but it's becoming extremely difficult to find any I don't already have.
  
  
  The same goes for many aspects of the VMS. I have collected about 3,000 samples of script that bear a resemblance to the style of writing on folio 116v, but even though I've put a ridiculous amount of effort into this, I have only found a couple of dozen that are really close based on the mathematical system I developed to compare them more objectively.
  
  It's not enough to fully put me in my comfort zone. I'm having trouble finding ones I don't already have (you have to look through about 20,000 manuscripts to find 3,000 samples) but I still don't have enough data to definitively say where the script originated. I am getting close, but I'm not there yet. As I said, it takes a long time and a lot of effort to confirm or deny how genuine a similarity may be.

• RE: Logic issues

  Davidsch > 26-04-2020, 10:04 PM

  What is interesting in this context, the Aristotelian logic flourished up to the 15th, even into the 17th century but then it was replaced by new methods.
  
  Especially since You are not allowed to view links. Register or Login to view.was not considered to be leading for science anymore,  (Darii for example is a mnemomic in syllogism which is interesting)
  because I believe it was Bacon and Descartes, proved that some problems were not solvable by that method.
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