Chopra and Weiss address perhaps the fundamental issue in international relations today: the sacrosanct sets of sovereignty. The word "sovereignty" explains why the international community has difficulty countering human rights violations.
To walk or not to walk: Should a batsman acknowledge his own dismissal by leaving the wicket without even waiting for the umpire's decision? David Coady and Samir Chopra examine this flashpoint ethical debate in cricket.
TRASCIENDE LOS OBSTÁCULOS QUE AFECTAN A TU CUERPO Y A TU ESPÍRITU 15 años después de su gran clásicoCuerpos sin edad, mentes sin tiempo, Deepak Chopra revisa el “milagro olvidado”—la capacidad infinita de renovación y cambio del ...
We propose a new relevance sensitive model for representing and revising belief structures, which relies on a notion of partial language splitting and tolerates some amount of inconsistency while retaining classical logic. The model preserves an agent's ability to answer queries in a coherent way using Belnap's four-valued logic. Axioms analogous to the AGM axioms hold for this new model. The distinction between implicit and explicit beliefs is represented and psychologically plausible, computationally tractable procedures for query answering and belief..
The axiom of recovery, while capturing a central intuition regarding belief change, has been the source of much controversy. We argue briefly against putative counterexamples to the axiom—while agreeing that some of their insight deserves to be preserved—and present additional recovery-like axioms in a framework that uses epistemic states, which encode preferences, as the object of revisions. This makes iterated revision possible and renders explicit the connection between iterated belief change and the axiom of recovery. We provide a representation theorem (...) that connects the semantic conditions we impose on iterated revision and our additional syntactical properties. We show interesting similarities between our framework and that of Darwiche–Pearl (Artificial Intelligence 89:1–29 1997). In particular, we show that intuitions underlying the controversial (C2) postulate are captured by the recovery axiom and our recovery-like postulates (the latter can be seen as weakenings of (C2)). We present postulates for contraction, in the same spirit as the Darwiche–Pearl postulates for revision, and provide a theorem that connects our syntactic postulates with a set of semantic conditions. Lastly, we show a connection between the contraction postulates and a generalisation of the recovery axiom. (shrink)
Traditional accounts of belief change have been criticized for placing undue emphasis on the new belief provided as input. A recent proposal to address such issues is a framework for non-prioritized belief change based on default theories (Ghose and Goebel, 1998). A novel feature of this approach is the introduction of disbeliefs alongside beliefs which allows for a view of belief contraction as independently useful, instead of just being seen as an intermediate step in the process of belief revision. This (...) approach is, however, restrictive in assuming a linear ordering of reliability on the received inputs. In this paper, we replace the linear ordering with a preference ranking on inputs from which a total preorder on inputs can be induced. This extension brings along with it the problem of dealing with inputs of equal rank. We provide a semantic solution to this problem which contains, as a special case, AGM belief change on closed theories. (shrink)
We present a method for relevance sensitive non-monotonic inference from belief sequences which incorporates insights pertaining to prioritized inference and relevance sensitive, inconsistency tolerant belief revision. Our model uses a finite, logically open sequence of propositional formulas as a representation for beliefs and defines a notion of inference from maxiconsistent subsets of formulas guided by two orderings: a temporal sequencing and an ordering based on relevance relations between the putative conclusion and formulas in the sequence. The relevance relations are ternary (...) (using context as a parameter) as opposed to standard binary axiomatizations. The inference operation thus defined easily handles iterated revision by maintaining a revision history, blocks the derivation of inconsistent answers from a possibly inconsistent sequence and maintains the distinction between explicit and implicit beliefs. In doing so, it provides a finitely presented formalism and a plausible model of reasoning for automated agents. (shrink)
Thinking about how the law might decide whether to extend legal personhood to artificial agents provides a valuable testbed for philosophical theories of mind. Further, philosophical and legal theorising about personhood for artificial agents can be mutually informing. We investigate two case studies, drawing on legal discussions of the status of artificial agents. The first looks at the doctrinal difficulties presented by the contracts entered into by artificial agents. We conclude that it is not necessary or desirable to postulate artificial (...) agents as legal persons in order to account for such contracts. The second looks at the potential for according sophisticated artificial agents with legal personality with attendant constitutional protections similar to those accorded to humans. We investigate the validity of attributes that have been suggested as pointers of personhood, and conclude that they will take their place within a broader matrix of pragmatic, philosophical and extra-legal concepts. (shrink)
We provide a formal study of belief retraction operators that do not necessarily satisfy the postulate. Our intuition is that a rational description of belief change must do justice to cases in which dropping a belief can lead to the inclusion, or ‘liberation’, of others in an agent's corpus. We provide two models of liberation via retraction operators: ρ-liberation and linear liberation. We show that the class of ρ-liberation operators is included in the class of linear ones and provide axiomatic (...) characterisations for each class. We show how any retraction operator can be ‘converted’ into either a withdrawal operator ) or a revision operator via the Harper Identity and the Levi Identity respectively. (shrink)
Claims about the potential of free software to reform the production and distribution of software are routinely countered by skepticism that the free software community fails to engage the pragmatic and economic ‘realities’ of a software industry. We argue to the contrary that contemporary business and economic trends definitively demonstrate the financial viability of an economy based on free software. But the argument for free software derives its true normative weight from social justice considerations: the evaluation of the basis for (...) a software economy should be guided by consideration of the social and cultural states which are the ultimate goals of any economic arrangement. That is, the software economy should be evaluated in light of its ability to provide justice. We conclude with a discussion of possible avenues for reform. (shrink)
We present a framework that provides a logic for science by generalizing the notion of logical (Tarskian) consequence. This framework will introduce hierarchies of logical consequences, the first level of each of which is identified with deduction. We argue for identification of the second level of the hierarchies with inductive inference. The notion of induction presented here has some resonance with Popper's notion of scientific discovery by refutation. Our framework rests on the assumption of a restricted class of structures in (...) contrast to the permissibility of classical first-order logic. We make a distinction between deductive and inductive inference via the notions of compactness and weak compactness. Connections with the arithmetical hierarchy and formal learning theory are explored. For the latter, we argue against the identification of inductive inference with the notion of learnable in the limit. Several results highlighting desirable properties of these hierarchies of generalized logical consequence are also presented. (shrink)
Possible-world semantics are provided for Parikh’s relevance-sensitive model for belief revision. Having Grove’s system-of-spheres construction as a base, we consider additional constraints on measuring distance between possible worlds, and we prove that, in the presence of the AGM postulates, these constraints characterize precisely Parikh’s axiom (P). These additional constraints essentially generalize a criterion of similarity that predates axiom (P) and was originally introduced in the context of Reasoning about Action. A by-product of our study is the identiﬁcation of two possible (...) readings of Parikh’s axiom (P), which we call the strong and the weak versions of the axiom. An interesting feature of the strong version is that, unlike classical AGM belief revision, it makes associations between the revision policies of different theories. (shrink)
The introduction of explicit notions of rejection, or disbelief, into logics for knowledge representation can be justiﬁed in a number of ways. Motivations range from the need for versions of negation weaker than classical negation, to the explicit recording of classic belief contraction operations in the area of belief change, and the additional levels of expressivity obtained from an extended version of belief change which includes disbelief contraction. In this paper we present four logics of disbelief which address some or (...) all of these intuitions. Soundness and completeness results are supplied and the logics are compared with respect to applicability and utility. (shrink)
The standard theory for belief revision provides an elegant and powerful framework for reasoning about how a rational agent should change its beliefs when confronted with new information. However, the agents considered are extremely idealized. Some recent models attempt to tackle the problem of plausible belief revision by adding structure to the belief bases and using nonstandard inference operations. One of the key ideas is that not all of an agent's beliefs are relevant for an operation of belief change.In this (...) paper we incorporate the insights pertaining to local change and relevance sensitivity with the use of approximate inference relations. These approximate inference relations offer us partial solutions at any stage of the revision process. The quality of the approximations improves as we allow for more and more resources to be used. We are provided with upper and lower bounds to what would be obtained with the use of classical inference. (shrink)
Dept of Business Administration Dept of Computer and Knowledge Systems Group University of Patras Information Science School of Computer Science 265 00 Patras, Greece Brooklyn College of the and Engineering email@example.com City University of New York University of New South Wales Brooklyn, NY 11210, USA Sydney, NSW 2052, Australia firstname.lastname@example.org email@example.com..
Although J. S. Mill′s essay On Liberty was intended by its author to be read as a self-contained work, 1 and even though a careful reading would justify seeing it in this way, it has far too often been denied this right even by its defenders. There is a crucial distinction to be made between eliciting some point of substance from a particular work by an author and then turning to the rest of his work to throw further light on (...) it, and employing other texts from the corpus of his writings to put the construction on certain things said in it which the work by itself cannot sustain, thus treating the former as essentially a fragment, albeit a most important fragment, of a whole. 2 I would suggest that recourse to the latter course is justified only when the possibilities of treating it autarchically have already been explored. In this paper I propose to treat a celebrated text in the former way only because I believe that the results will show such an approach to be uniquely worthwhile, or at least fruitful enough to justify a paper conceived in this way. And, with a view to putting what I want to say about it in maximum focus I shall with one or two exceptions eschew giving supporting evidence from Mill′s other writings, even when this is permitted by the distinction I have made in this opening paragraph. (shrink)
In a paper entitled ‘Saints and Heroes’ 1 Professor J. O. Urmson has criticised ‘the trichotomy of duties, indifferent actions, and wrongdoing’ , commonly found in moral philosophy, on the ground that it fails to cover an important class of actions, of which saintly and heroic actions are ‘conspicuous” but by no means the only examples. I am inclined to think that this trichotomy is defensible, and that at least it deserves a much longer run for its money than Urmson (...) gives it. The form in which he presents it, however, makes it more implausible than it need be and this is perhaps the main reason why he finds it so indefensible. (shrink)
The “free” in “free software” refers to a cluster of four specific freedoms identified by the Free Software Definition. The first freedom, termed “Freedom Zero,” intends to protect the right of the user to deploy software in whatever fashion, towards whatever end, he or she sees fit. But software may be used to achieve ethically questionable ends. This highlights a tension in the provision of software freedoms: while the definition explicitly forbids direct restrictions on users’ freedoms, it does not address (...) other means by which software may indirectly restrict freedoms. In particular, ethically-inflected debate has featured prominently in the discussion of restrictions on digital rights management and privacy-violating code in version 3 of the GPL (GPLv3). The discussion of this proposed language revealed the spectrum of ethical positions and valuations held by members of the free software community. In our analysis, we will provide arguments for upholding Freedom Zero; we embed the problem of possible uses of software in the broader context of the uses of scientific knowledge, and go on to argue that the provision of Freedom Zero mitigates against too great a moral burden—of anticipating possible uses of software—being placed on the programmer and that, most importantly, it facilitates deliberative discourse in the free software community. (shrink)
In a paper entitled ‘Saints and Heroes’ 1 Professor J. O. Urmson has criticised ‘the trichotomy of duties, indifferent actions, and wrongdoing’, commonly found in moral philosophy, on the ground that it fails to cover an important class of actions, of which saintly and heroic actions are ‘conspicuous” but by no means the only examples. I am inclined to think that this trichotomy is defensible, and that at least it deserves a much longer run for its money than Urmson gives (...) it. The form in which he presents it, however, makes it more implausible than it need be and this is perhaps the main reason why he finds it so indefensible. (shrink)