François Jacob on possible worlds

François Jacob (1920–2013)

“Plus que jamais, la recherche me paraissait s’identifier à la nature humaine. En exprimer l’appétit, le désir de vivre. C’était bien le meilleur moyen trouvé par l’homme de braver le chaos de l’univers. De dominer la mort.” (More than ever, scientific research seemed to me to be intrinsic to human nature. It expressed the hunger, the desire to live. It has, in fact, been the best means found b...

19 April 2013 − − François Jacob . 17 June 1920

On Combinatorial Possible Worlds

Combinatorial worlds can be used to give an account of necessity and possibility. Both accessibility and similarity between worlds can be deened. In this paper, we claim that combinatorial worlds can form a knowledge representation framework, and provide an interesting approach to nonmonotonic reasoning and belief revision. We investigate such aspects of the combinatorial worlds framework as co...

Possible Worlds

No formula binds me in this so-called opening address, but it is more usual for the speaker to trace the historical evolution of some part of that, branch of medicine of which he is a devotee. Looking back in recent years, I find that this field has been so often cultivated, albeit by a rotation of crops, that I feel it should lie fallow for a while. I might, in a popular address, recount the c...

Unawareness with "possible" possible worlds

Logical structures for modeling agents’ reasoning about unawareness are presented where it can hold simultaneously that: (i) agents’ beliefs about whether they are fully aware need not be veracious with partitional information; and (ii) the agent is fully aware if and only if she is aware of a fixed domain of formulae. In light of (ii), all states are deemed “possible”. Semantics operate in two...