I Know What You Mean

So I tell you something and you tell me “I know what you mean”. But what do you mean when you tell me this? In order to know, I must know what “know” means, or what you mean by “know”. And that is an open and non-trivial epistemological question. And then I must know what you mean by "mean”. And that requires requires for me to believe that you are using the same natural language semantics to interpret what I utter as I use to generate what I utter, yet another forever open question from linguistics.

Considering this, it must be a miracle that we manage to communicate at all. I just hope you are less confused and lost in this maze of meaninglessness and ignorance than I am right now. I hope that you know what I mean. Because I skeptically don’t…

The Great Firewall of China

It is a well-known fact that internet users in China cannot access blogs stored in the “blogspot.com” domain. And yet, one of the website statistics tools that I use shows that my blog has had one visitor from China. I wonder how…

The Disjunctive “And”

In natural language, we sometimes say “and”, but actually mean “or”.

For example:

1) “Brasil accepts argentinian and chilean tourists without visa”.

Let’s put parentheses for scoping:

2) “Brasil accepts ((argentinian and chilean) tourists) without visa”.

Literally, this would mean that a tourist can enter Brasil without a visa, if he has both argentinian citizenship and chilean citizenship. But this is not what we mean when we say a sentence like that. We actually mean that the tourist can enter, if he has either of argentinian or chilean citizenship. So, we use “and”, but we actually mean a disjunction. We mean:

3) “Brasil accepts argentinian or chilean tourists without visa”.

This strange behaviour of “and” can be explained by ellipsis together with wrong distribution of connectives (De Morgan’s rules).

This is the original sentence again, with the ellipses shown explicitly within square brackets:

4) “Brasil accepts argentinian [tourists without visa] and [Brasil accepts] chilean tourists without visa”.

Sentence 4 can be formalized as:

4F) (Argent(x) –> Accept(x)) and (Chilean(x) –> Accept(x))

Sentence 2 can be formalized as:

2F) (Argent(x) and Chilean(x)) –> Accept(x)

And here is a formalization of what we actually mean:

3F) (Argent(x) or Chilean(x)) –> Accept(x)

The point is that we want to say 4. But then we realize that it is very redundant, and many things are repeated. This repetition is specially clear in 4F, where the predicate “Accept” appears twice. Logically, we could avoid this by putting the predicate “Accept” in evidence. Any trained and disciplined logician knowing De Morgan’s rules of distribution of classical negation over “and” or “or” and knowing that, classically, “(A –> B) = (not A or B)” holds, would soon figure out that the correct way of putting “Accept” in evidence requires changing the “and” to an “or”, and hence he would get to 3F, and he would say 3 during a conversation. But normal people, on the other hand, just do lazy ellipses and leave the “and” hanging there. They pronounce 1, which literally means 2F, but they actually want to mean 3F. And thus the disjunctive and is born, basically because people are lazy and can’t apply De Morgan’s rules correctly.

Kein Sex mit Nazis

For those who do not speak german, here is a translation:  “no sex with nazis”.

It seems that, while the nazi part of Austria uses conventional propaganda, displaying and distributing advertisements and slogans against foreigners, the non-nazi part of Austria is much more creative in the methods it uses…

In fact, I remember that the non-nazi part of Dresden also used to promise no sex with nazis in parties like the Bunte Republik Neustadt…  So, perhaps there is an international underground anti-nazi group centered on the idea of preventing nazis from sex (with non-nazis)!

Recently Watched Movies

A Problem of Paper-Counting Research Merit Assessment

If you happen to have an interesting scientific idea and manage to publish an initial sketch of it, it is possible that many other people will find it cool, enhance your sketch and cite it in their own papers.

However, if you happen to be a perfectionist and decide not to publish a sketch but to investigate your idea more deeply for a few years and publish it only when it is fully worked out, then possibly no one else will be able or interested to follow and cite your idea, simply because there is no more work to be done.

Poincare Archive

The EpiConFor workshop was held in a university whose library keeps many treasures for the history of science, including many original manuscripts of Poincare, handwritten letters from members of the Vienna circle, and an original copy of Herbrand's thesis. And we had the opportunity to have a close look at all that.

Knowledge as Justified although not Necessarily True Belief

Knowledge is frequently "defined" as justified true belief. However, it seems that Epistemologists pay much more attention to the truth aspect than to the justification aspect. In my opinion, it should be the other way around, and I would even say that knowledge doesn't have to be true. To illustrate this point, we can consider an example from Euclidian geometry:

Suppose that a person reads a book about Euclidian geometry and believes in the axioms stated there. Furthermore, the person reads the proof that the sum of the internal angles of a triangle equals 180 degrees. Now she has a justified belief in this theorem, and thus, in my opinion, she is entitled to claim that she knows that the sum of the internal angles equals 180 degrees.

However, if she happens to be living in a general relativistic world in which spacetime is not flat, it will be false that the sum of the internal angles of a triangle equals 180 degrees. So, it just happens that she has a false knowledge, a justified false belief.

Proofs and Knowledge

Why do we say that a Mathematics book contains knowledge? Because it contains proofs of the theorems it claims. This fact alone is a strong evidence that proofs should play a major role in epistemology.

Even the knowledge contained in a Biology, Physics or Chemistry book is trusted because it is backed up by many experiments, and an experimental procedure can be regarded as a proof procedure.

So, I find it strange that epistemologists (at least the ones I have seen at the EpiConFor) do not pay so much attention to proofs. They are basically ignoring how science produces what it calls knowledge.

In fact, in my opinion the importance of proofs is so high that rigorous formal epistemology is nothing but proof theory.

EpiConFor

The EpiConFor workshop about epistemology is almost coming to an end now and it has been very interesting to participate. There were many confusing talks, as I expected, but some speakers managed to present ideas that were either in tune or challenging to my own views about knowledge. In general, my own ideas about knowledge became richer, more precise and more solid during this workshop.

I particularly liked Julien Dutant's talk about "Methods-based Models for Knowledge", in which an agent's knowledge is the result of the agent's usage of certain methods, instead of just being given by usually unreasonable epistemic modal logic axioms, and Vincent Hendricks' talk about "General Dynamics: Agents and Agendas", which contains a very mathematical approach with the world modeled as a stream of information that is observed by agents that discover and assess hypotheses about it.

I am already familiar with modal epistemic and doxastic logics, mainly due to my participations in previous ESSLLIs, and hence Johan van Benthem's talk was not significantly informative to me. However, it was a good opportunity to see how excellent a speaker he is, being able to explain everything with clarity in a short amount of time and yet with a great sense of humour. It was a bit disappointing to see how he employed some tricky examples in order to downplay the importance of inferences and proofs for knowledge.

In fact, I think that Proof Theory could and should be playing a bigger role in EpiConFor and Epistemology in general.

Overspecialization (and other Problems) in Mathematics (and other Theoretical Sciences)

A friend of mine pointed me a blog post complaining about overspecialization in mathematics. That is indeed the case. When I attend workshops in my own area, I feel much more ignorant than when I attend workshops or lectures in other areas, even if I don’t have much educational background in them.

However, I think that the overspecialization in theoretical sciences also has some positive sides. The fact that I frequently don't understand what colleagues of mine present can be seen as evidence that their works are sufficiently original and deep, and the results are inherently hard to achieve. In other areas, on the other hand, I have the impression that there are many people working on the same things, which often seem to be quite trivial, given that I can understand them even without much background.

And clearly, the science business model currently favours the other areas, since it is easier to write a paper about trivial things, and the paper is more likely to be published somewhere and receive many citations, because there is a larger community interested in the trivial topic.

From this point of view, the mathematician's overspecialization could be seen as a kind of academic bravery to tackle hard problems alone and to resist the current trend in science that confuses value with popularity.

(Just for the record: I'm not a mathematician, although my research has become more and more mathematical and theoretical along the years. I try to be generalist and specialist simultaneously, acquiring specific knowledge and contributing to a specific area while also trying to extrapolate this knowledge to other areas: my changes of research area and the last chapter of my thesis are evidences for this. Nevertheless, I don't think that those who choose to be only specialists should be criticized and undervalued.)

In Vienna, Golf Kills

Donauturm

In order to commemorate the successful defense of my thesis, my parents encouraged Katya and I (both conceptually and financially) to go to a fancy restaurant. We chose to go to the Donauturm restaurant, the rotating restaurant on the top of the television tower across the river Danube.

It was a great choice. The views from there are spectacular. Vienna is an amazing metropolis.

We were also lucky with the weather, because we saw it changing so drastically. Initially very cloudy, it gave Vienna the atmosphere of a dark gothic cyberpunk big city, illuminated only by a few sunrays that trespassed the clouds. By the end of our lunch, however, the sky was already completely blue, with not a single cloud; a cheerful weather matching Vienna's characteristic village-like nature despite its size.

For lunch we had Zwiebelrostbraten, which is my favourite Austrian dish, and potato soup.

For those who are out of their minds, it is possible to do bungee jumping from the tower too.

Vegetasia

Vegetasia is an unusual asian vegetarian restaurant in the 7th district of Vienna. Although it is vegetarian, the menu is full of meat, chicken, pork and fish dishes. Surprisingly, though, these dishes are also vegetarian. The meat is just imitated with different kinds of tofu, mushrooms and vegetables. And the imitation is so perfect that it is quite plausible to believe that you are actually eating meat, if nobody tells you the truth.  I find this both interesting and disturbing. It makes us wonder how we can be sure that we are buying and eating real meat elsewhere...   Anyway, the food in Vegetasia is delicious…

No Wireless Internet for Foreigners in Austria

A visiting professor from Brazil, who is going to stay in Vienna for one year, needs Internet in his home. Since he will be travelling frequently, he preferred wireless Internet. However, most companies offering wireless internet in Austria require contracts lasting for at least two years. One exception was Orange, a company that makes contracts lasting 12 months. However, Orange requires the client to be living in Austria for at least 3 months, which was not his case, because he has just arrived. So I agreed to make the contract in my name. Orange required my passport, my Meldezettel and my residence permit, as expected. We filled and signed all the bureaucratic forms, and the seller sent them by fax to the Orange headquarters for approval. We waited 30 minutes.  And the contract was rejected. The reason is that my current residence permit is not valid for at least 12 months. However, Austria never gives residence permits that are valid for more than 365 days. In Austria, foreigners have to extend their residence permits every 350 days (because the extension procedure takes 15 days) and paying 113 Euros to do so.

In summary, if you are a foreigner in Austria, you don’t have the right to own and use a wireless internet modem. And what is most annoying is that they don’t say this explicitly, but instead create several rules that, when isolated, do sound very reasonable, while together implicitly create the desired effect against foreigners.

That is an example of how Austrian xenophobia and racism work in the daily life,  apart from the useless theatre of politics (in which Strache at least expresses his non-sense explicitly). And you can’t even complain, because each Austrian or each Austrian institution (e.g. Orange, the Austrian Ministerium of the Interior,…) cleverly exploits others’ reasonable rules (e.g. Orange justifies itself by saying that it is not its fault that the Austrian government doesn’t give long residence permits, and the Austrian government justifies itself by saying that it is not its fault that Orange requires long residence permits).

Austria exhibits a strong synergic racist behaviour, even though many individual Austrians and Austrian institutions frequently cannot be classified as racist. They are just following their rules (e.g. the Orange seller was very friendly to us).

(Just for comparison, in Germany I made a two-year contract for a mobile phone and, if I remember correctly, I didn’t even have a residence permit, but just a temporary visa that was going to expire in a few weeks…)

Artificial Food

I have probably already complained that food here in Europe is not as tasty as in Brazil. It looks great, but it tastes artificial. And now, as the news below explains, it seems that part of it not only tastes artificial, but is indeed artificial. More specifically, it seems that there is ham not made of meat and cheese not made of milk being sold in Austrian supermarkets…

The news complains that these products are not stating clearly enough to the costumers, that they are not really made of meat and milk.

Detained in London

This is a great PhD Comics story about how UK (and also EU and US) immigration policies are stupid and annoying!

Once I was almost detained in London too, and I just had to do a connection (changing airports) there when going back from a conference in Iceland to Austria...

UK is a cold prison... Just look at all its cameras... I don't understand why people would want to live there anyway...