The Independent Choice Logic began in the early 90’s as a way to combine logic programming and probability into a coherent framework. The idea of the Independent Choice Logic is straightforward: there is a set of independent choices with a probability distribution over each choice, and a logic program that gives the consequences of the choices. There is a measure over possible worlds that is de...

One version of the argument for design relies on the assumption that the apparent fine-tuning of the universe for the existence of life requires an explanation. I argue that the assumption is false. Philosophers who argue for the assumption usually appeal to analogies, such as the one in which a person was to draw a particular straw among a very large number of straws in order not to be killed....

Robert Nozick’s tracking account of knowledge is defended against Colin McGinn’s criticisms by drawing on David Deutsch’s ’multiverse’ conception of possible worlds. Knowledge on the tracking account requires a ’method’ or ’way’ of believing. Exploiting this feature undercuts the apparent force of McGinn’s counter-examples. This essay focuses on Colin McGinn’s critique in Knowledge and Reality ...

Adams’ Thesis the claim that the probabilities of indicative conditionals equal the conditional probabilities of their consequents given their antecedents – has proven impossible to accommodate within orthodox possible worlds semantics. This paper considers the approaches to the problem taken by Jeffrey and Stalnaker (1994) and by McGee (1989), but rejects them on the grounds that they imply a ...

Many people view arts and sciences as being different because sciences yield objective answers to problems whereas arts produce subjective experiences I argue that art and science are on a continuum in which artists work with possible worlds whereas scientists are constrained to working in this world. But sometimes perceiving this world differently is the key to making discoveries. Thus, arts a...

In this paper, the relationship between the thermodynamic and historical arrows of time is studied. In the context of a simple combinatorial model, their definitions are made more precise and in particular strong versions (which are not compatible with time symmetric microscopic laws) and weak versions (which can be compatible with time symmetric microscopic laws) are given. This is part of a l...

In this paper, we analyze the relationship between commitment and obligation from a logical viewpoint. The principle of commitment implying obligation is proven in a specific logic of action preference which is a generalization of Meyer’s dynamic deontic logic. In the proposed formalism, an agent’s commitment to goals is considered as a special kind of actions which can change her deontic prefe...

What is a matrix characterization? We give a formal answer to this question by the deenition of matrix systems. They provide a framework in which all major existing matrix characterizations can be presented uniformly and also support the development of new ones. We describe how to develop a matrix characterization from a sequent calculus. Once a matrix characterization exists, a close relation ...

Do mathematical expressions have intensions, or merely extensions? If we accept the standard account of intensions based on possible worlds, it would seem that the latter is the case – there is no room for nontrivial intensions in the case of non-empirical expressions. However, some vexing mathematical problems, notably Gödel’s Second Incompleteness Theorem, seem to presuppose an intensional co...

3 Actions: Moving Between Situations 4 3.1 Representing Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.1 Add and Delete Lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.2 Direct and Indirect Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Computing the Results of Actions . . . . . . . . . . . . . . . . . . . . . . ....