## Jaakko Hintikka and Information in Philosophy

Though not something that I deliberately worked towards, I realise that much of the work I have done or am doing is in areas either initiated or influenced by Jaakko Hintikka.

• My honours thesis looked at game-theoretical semantics and independence-friendly logic, which Hintikka is the main architect of.
• I also work with epistemic logic quite a bit, of which Hintikka’s Knowledge and Belief: An Introduction to the Logic of the Two Notions is a seminal text.
• I am currently using Hintikka’s approach to analysing questions as requests for information in terms of epistemic modal logic for some research on informational relevance.
• The approaches to truthlikeness that I am using for information quantification make use of Hintikka’s distributive normal forms.
• The work by Bar-Hillel/Carnap on quantifying semantic information was extended by Hintikka.

## Talk on a Logic for Agent-Oriented Relevance

Details for an upcoming talk I am giving:

Title: A Logic for Agent-Oriented Relevance

Abstract: Relevance here is taken to be agent-oriented/epistemic, where the relevance of a piece of information is determined in terms of how well it satisfies an agent’s request, how well it answers their question. A logic is given in which a relevance operator (Ra) is defined and investigated; Rai means something like ‘the piece of information i is relevant to agent a’. The erotetic foundation for this logic is Hintikka’s approach to analysing questions as requests for information in terms of epistemic modal logic, which is then combined with a logic of intention.

Location: Melbourne University Logic Seminar Series, September 17th.

## Talk on Knowledge and Information

Details for an upcoming talk I am giving. Date and time TBA:

Title: Knowledge and Information

Abstract: Information and knowledge are commonly associated with each other; colloquially, in dictionaries, the two terms are often treated as synonymous. Within philosophy however, information-theoretic epistemology goes beyond this casual, colloquial association. It involves the development of specialised accounts of information and furthermore attempts to develop an explication of knowledge with such accounts, to show how information causes or leads to knowledge. In this presentation I outline and discuss a theory of information and how it is used to develop an information-theoretic epistemology. Information is treated as a fundamental precursor to knowledge, with knowledge encapsulating truth because it encapsulates information, which itself is also veridical by definition.

## Vlatko Vedral: Everything is information

Was listening to the Sun, 11 Jul 10 edition of the BBC’s The Forum program, in which Physicist Vlatko Vedral was a participant. Decided to look at some of his stuff and found this: Vlatko Vedral: Everything is information

Here Vedral explains why he believes the fundamental stuff of the universe is information – and how he hopes that one day everything will be explained in this way.

He has recently published a book title Decoding Reality: The Universe as Quantum Information.

Looks interesting, but I should read my copy of Seth Lloyd’s Programming the Universe: A Quantum Computer Scientist Takes on the Cosmos before I get another book on the matter.

## A New Introduction to Modal Logic erratum

Just noticed a significant and potentially confusion causing error regarding multiply modal logics in this nonetheless excellent text. On pages 217-218 in my 1996 edition Hughes and Cresswell write:

For instance we might have a necessity operator $L_{1}$, say, which is stronger than $L_{2}$ in the sense that $L_{1} p \supset L_{2}p$. The canonical model for such a system would obey the restriction that for all $w, w' \in \text{W},$ if $w\text{R}_{1}w'$ then $w\text{R}_{2}w'.$

Now, that should be for all $w, w' \in \text{W},$ if $w\text{R}_{2}w'$ then $w\text{R}_{1}w'$.

## Latex, Logic and WordPress

I am currently writing up some notes in $\LaTeX$, including jotting down a sequent system. I have typed up a sequent system in $\LaTeX$ before, but could not remember how I did it and cannot find the .tex source for it. So I headed down to the excellent $\LaTeX$ for Logicians to refresh my memory.

How am I typesetting the $\LaTeX$ logo in this post you ask? Well, whilst searching for $\LaTeX$ and logic, I also discovered the possibility of including $\LaTeX$ in WordPress posts. Here is an article discussing this: http://www.logicnest.com/using-latex-in-wordpress. Great stuff!