D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-54. IOS Press, 1999.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....over the worlds which is strictly sensitive of the number of reciprocal incompatibilities (potential violations) between norms. A di#erent approach, inspired by similar intuitions, has been developed in particular by D. Makinson and L. van der Torre. Their main idea, as pointed out by Makinson [12] himself, is to be traced back to a pionieristic work by Stenius [19] and it has been later improved by Alchourron and Bulygin [2, 1] This line of investigation is based on the intuition that any obligation can be thought in terms of a consequence relation of what is explicitly stated as ....

....worlds and so forth. 6 Dealing with CTD Paradoxes Now, let us see how to deal in our system with some of the most infamous paradoxes of CTD reasoning. In particular, we want to give a formal account of Chisholm s [6] and Forrester s [7] paradoxes, Belzer s [4] Reykjavik scenario and Makinson s [12] Mobius strip example . Since these puzzles are well known in the deontic logic community we shall not recall any of their intuitive examples but we will confine our analysis to their logical representation in our formalism. Chisholm s Paradox The basic scenario depicted in Chisholm s paradox ....

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D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics, and Information Systems, pages 29--53. IOS Press, Amsterdam, 1999.

....specify properties for the component based cognitive agents [3, 8] where agents mental attitudes are conditional and represented as components. Note that motivational attitudes such as desires are usually represented by conditionals (or rules) which has been studied in particular in deontic logic [1, 12]. One type of properties that are abstracted from in the BDI approach is based on the functional dependency between mental attitudes. We say that there is a functional dependency between two mental attitudes if one of them completely determines the other. For example, the dependency between the ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29--54. IOS Press, 1999.

.... about norms: how to proceed when a norm is violated There is a huge philosophical literature on deontic logic, but there are hardly any up to date surveys, there is no consensus or commonly accepted standard theory, nor a commonly accepted list of open problems or benchmark examples (but see [44,69]) most traditional logics lack concepts like agents, time, and actions to represent multi agent systems, most proposals in arti cial intelligence and computer science are relatively complicated (see e.g. 51,10,70] and most proposed formalisms seem to have counterintuitive properties. This at ....

.... independence relation is suggested by the explicit manner of presentation, because F (p d) is deontically independent of d only if it is given explicitly (in N 2 ) Deontic independence can also be used to analyze the Reykjavik Scenario [7,64] The example is taken from a discussion by Makinson [44]. The explicit obligations are that neither Reagan nor Gorbatchov should be told the secret, if Reagan is told the secret then Gorbatchov should be told, and if Gorbatchov is told then Reagan should be told. Intuitively, under the condition that Gorbatchov is told, we would like to be able to ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-54. IOS Press, 1999.

....are used in the agent s planning and to plan to achieve goal p it is irrelevant whether there is an intention, desire or obligation to see to it that p. Note that it is important in the implementation [4] There have also been convincing philosophical arguments to do without modal operators, see [9]. Advantages of this extension are the formalization of more complex notions like permissions and ignorance. 4 No wishful thinking Thomason [18] argues that beliefs override desires with the following example. If you think it is going to rain and you believe that if it rains, you will get wet, ....

D. Makinson. On a fundamental problem of deontic logic. In Norms, logics and information systems, pages 29-53. IOS Press, 1999.

....it. Indeed, from the 1960s onwards, the semantic approach in terms of possible worlds deepened the gap. The rst serious attempt by a logician to face the problem appears to be due to Stenius [13] followed by Alchourr on and Bulygin [2] for unconditional norms, then Alchourr on [1] and Makinson [7] for conditional ones. Input output logic may be seen as an attempt to extract the essential mathematical structure behind these reconstructions of deontic logic. Like every other approach to deontic logic, input output logic must face the problem of accounting adequately for the behaviour of ....

....with A, for G 0 ranging over subsets of G. Every maximal value of out(G 0 ; A) is in the outfamily, but not always conversely. For certain of our output operations, the two families do coincide, but not for others. This can be shown by simple examples, such as the M obius strip of Makinson [6, 7]. Put G = f(a; x) x; y) y; a)g. Then, for out = out 3 or out = out4 , maxfamily(G; a) has three elements, namely the three two element subsets of G. As a result, outfamily(G; a) also has three elements Cn( Cn(x) and Cn(fx; yg) Of these, only the last is a maximal value of out(G 0 ; ....

Makinson, David (1999). On a fundamental problem of deontic logic, In Paul McNamara and Henry Prakken eds Norms, Logics and Information Systems. New Studies in Deontic Logic and Computer Science, Amsterdam: IOS Press, Series: Frontiers in Articial Intelligence and Applications, Volume 49, pp. 29-53.

....into all unawares can have powerful side e ects, however, and as deontic logic matures, we must constantly reexamine our work to identify the assumptions we use and to consider their e ects. From the first, treatments of deontic logic have been beset by a variety of paradoxes or rather, as Makinson (1999) has more accurately put it, have Nordic Journal of Philosophical Logic, Vol. 5, No. 2, pp. 83 112. 2000 Taylor Francis. 84 mark a. brown failed to deal satisfactorily with various benchmark examples. These failures, we must suspect, are often symptomatic of the acceptance of unduly simple ....

Makinson, D. 1999. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken (eds.), Norms, Logics and Information Systems: New Studies in Deontic Logic and Computer Science, vol. 49 of Frontiers in Artificial Intelligence and Applications, pp. 29--53. IOS Press, Amsterdam.

....goal of B. To prove these surprising theorems the global consistency constraint as well as the ordering of proof rules is implemented in versions of Gabbay s labelled deductive systems [5] In particular, we use and adapt the labelled logics introduced by Van der Torre [15, 16] and Makinson [9] for defeasible goals. The labelled logic of conditional goals is based on a language of formulas of the type G( j )L , to be read as is preferred (or desired) if in the proof context L. The label L collects the goals used in the proof to check the consistency of the ful llments, and it ....

....like p :p. First, in [15] the so called violation restriction is based on the material conditional of premises G( j ) the negation of the material conditional is the violation : and it is suggested that this restriction is best suited for normative contexts. 1 Second, in [9] the label contains a separate set of goals 1 In [15] the violation restriction checks whether ful lling a derived goal does not imply the violation of one of the goals it is derived from. However, to block some obvious counterintuitive derivations in Example 2 of that paper this should be ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science. IOS Press, 1998.

.... analyze security issues about electronic networks [CF97] to represent norms in qualitative decision theory [Pea93, Bou94b, Lan96] and to represent rights, duties and commitments in multi agent systems [vdTT99b] A further increase may be expected now recently developed prescriptive deontic logics [Mak99, vdTT99d, MvdT99] have delivered some promising approaches for the following longstanding problems in normative reasoning and their notorious deontic paradoxes. 1 Norms and normative propositions. The conceptual issue of the distinction between norms (that do not have truth values) and normative propositions ....

....observed that at the present state of play, it would not seem advisable to try to cover all complicating factors [of deontic logic] at once, but rather to get an initial appreciation of them few at a time, only subsequently putting them together 3 and investigating their interactions. In [Mak99, vdTT99d, MvdT99] only non defeasible obligations in a propositional setting have been studied, and in this paper only defeasible obligations in a propositional setting are studied. To keep our analysis as simple as possible we do not extend the language with permissions and prohibitions, a first order base ....

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D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29--54. IOS Press, 1999.

....It is the only deontic logic we know of besides the extensions discussed below that gives the desired properties for the benchmark examples in Table 1. However, other benchmark examples have been proposed more recently, for which PDL does not give the desired conclusions. For example, in [42] it is argued that it is desired to derive O(a j ) from O(a b j c) and O(a :b j :c) This example illustrates two drawbacks of PDL: it does not have weakening of the consequent (or consequential closure) and it does not have the disjunction rule for the antecedent. These two properties are a ....

....generalized to the logic of reusable propositional output (joint work with David Makinson) 43,68] The further developments have been summarized in the following table. WC OR noTV noId related PDL [76] CDL [59] 2DL [66] 74] DUS [75,79,78] 70] LDL [42,43,68,65 67] For applications, the logic PDL clearly needs additional expressive power. Makinson observed in 1993 [41] that at the present state of play, it would not seem advisable to try to cover all complicating factors [of deontic logic] at once, but rather to get an initial appreciation of them few at ....

[Article contains additional citation context not shown here]

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29--54. IOS Press, 1999.

....notion descriptive obligation to reason about the obligations that actually hold in a particular deontic state. Prescriptive obligations are motivated in part by a long standing philosophical discussion on whether it is meaningful to ascribe truth values to norms [ Alchourr on and Bulygin, 1981; Makinson, 1998; van der Torre and Tan, 1998b ] The semantics of our logic also cannot be based on truth values, because actions are not true or false. Instead it is based on the so called update semantics. Update semantics [ Veltman, 1996 ] is based on the notions of update action and acceptance. An update ....

....The prescriptive operators could easily be combined with standard descriptive operators and mixed all thingsconsidered operators, because they are all de ned in a preference based framework. Strong permissions. The framework contains strong permissions needed in multi agent environments. Makinson [ 1998 ] shows that one of the merits of prescriptive deontic logics is that they also enable natural distinctions between weak and strong permissions and various ways of relating them to obligations, but thus far no strong permission for traditional possible worlds semantics had been given. ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-53. IOS Press, 1998.

.... Falcone, 1997) to represent norms in qualitative decision theory (Pearl, 1993; Boutilier, 1994; Lang, 1996) and to represent rights, duties and commitments in multi agent systems (van der Torre and Tan, 1999b) A further increase may be expected now recently developed prescriptive deontic logics (Makinson, 1999; van der Torre and Tan, 1998a) have delivered some promising approaches for the following long standing problems in normative reasoning and their notorious deontic paradoxes. Contrary to duty. The conceptual issue of the contraryto duty paradoxes is how to proceed once a norm has been violated. ....

Makinson, D. (1999). On a fundamental problem of deontic logic. In McNamara, P. and Prakken, H., editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-- 54. IOS Press.

.... (a normative proposition) refers to a set of prescriptive obligations (the norms or the normative system) 39] This reflects the distinction, much debated in the philosophical literature, between descriptive obligations, that have a truth value, and prescriptive obligations, that do not [1, 41, 18, 39, 35, 38, 37]. The norm context is explicitly represented in labeled deontic logic [31, 18, 32] see also [19, 30] A descriptive obligation flff L contains a label L that represents the norm context in which the obligation for ff is derived, and it thus explains why the obligation is derived. The violation ....

.... normative system) 39] This reflects the distinction, much debated in the philosophical literature, between descriptive obligations, that have a truth value, and prescriptive obligations, that do not [1, 41, 18, 39, 35, 38, 37] The norm context is explicitly represented in labeled deontic logic [31, 18, 32], see also [19, 30] A descriptive obligation flff L contains a label L that represents the norm context in which the obligation for ff is derived, and it thus explains why the obligation is derived. The violation context of a descriptive obligation refers to a set of violations of prescriptive ....

[Article contains additional citation context not shown here]

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29--54. IOS Press, 1999.

....obligations are interpreted dynamically whereas descriptive obligations are interpreted statically. For example, in Alchourr on s box metaphor norms are characterized as a kind of actions. Moreover, another example of a dynamic interpretation of norms can be found in Makinson s iterative approach (Makinson, 1998). 1 Syntactic axiomatic presentation. Alchourr on and Bulygin asked themselves the question whether the logic of prescriptive obligations and the logic of descriptive obligations are different from a syntactic axiomatic point of view. They argue that there is an important difference related to ....

Makinson, D. (1998). On a fundamental problem of deontic logic. In This volume.

....3.4) However, a consistency check on the consequents would obviously block the derivation. Two solutions have been proposed to cover the parallel tracks created through reasoning by cases. First, in [vdT98a] the label of premises G(ff j fi) contains the material conditional fi ff. Second, in [Mak98] the label contains a separate set of formulas for each case. Hence, in the latter more flexible solution, which we adopt here too, the label contains sets of sets of boolean formulas. As far as reasoning by cases is concerned in the latter solution the labels of the premises G(ff j fi) can either ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science. IOS Press, 1998.

....may successfully be analyzed in update semantics and he gives a detailed analysis of one such phenomenon: default reasoning. To define obligations in update semantics we have to define ciation of them few at a time, only subsequently putting them together and investigating their interactions. In [11, 25] only nondefeasible obligations in a propositional setting have been studied. The language of dus now can be extended with permissions (following the suggestions in [20] and prohibitions, a first order base language, nested conditionals (following [27] background knowledge (following [19] ....

....establishing a conflict is not a violation) and they therefore cannot be used for prima facie obligations. Belief Revision Nonmonotonic Reasoning 41 L.W.N. van der Torre and Y. H. Tan 4 Conclusions In this paper we extended our dynamic approach to formalizing norms [25] Moreover, in [11] an iterative approach is proposed. Besides taking into account the philosophical issue that norms do not have a truth value, 8 the dynamic and iterative approaches also give better analyses of the benchmark examples of deontic logic, in particular the deontic paradoxes. 9 In this paper we ....

D. Makinson, `On a fundamental problem of deontic logic', in Proceedings of the \DeltaEON'98, pp. 3--42, (1998).

....tea nor coffee. The three problems lead to restricted applicability of proof rules, which we study in this paper with versions of Gabbay s labelled deductive system [ Gabbay, 1996 ] In particular, we use and extend the labelled logics introduced by Van der Torre [ 1998a; 1998b ] and Makinson [ Makinson, 1998 ] The distinction between the approaches of Van der Torre and Makinson is that the first is more cautious with respect to the treatment of conflicting contexts. We follow this more cautious approach, because its more constructive character has attractive computational properties. This so called ....

....a consistency check on the consequents would obviously block the derivation. Two solutions have been proposed to cover the parallel tracks created through reasoning by cases. First, in [ van der Torre, 1998a ] the label of premises G(ff j fi) contains the material conditional fi ff. Second, in [ Makinson, 1998 ] the label contains a separate set of formulas for each case. Hence, in the latter more flexible solution, which we adopt here too, the label contains sets of sets of boolean formulas. As far as reasoning by cases is concerned in the latter solution the labels of the premises G(ffjfi) can ....

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science. IOS Press, 1998.

....look for a consistency check to block strengthening of the context (Prakken Sergot, 1996) or strengthening of the antecedent (Prakken Sergot, 1997) Moreover, in (Prakken Sergot, 1997) they show it is impossible to construct such a consistency check in the classical Hansson Lewis semantics. Makinson (Makinson, 1998) proposes a labeled deontic logic in which the inference relation is relative to a set of explicit promulgations following (Alchourr on Bulygin, 1981) He uses an hypothesis that ensures that obligations are not strengthened to another context. However, this hypothesis is not represented in the ....

Makinson, D. 1998. On a fundamental problem of deontic logic. In McNamara, P., and Prakken, H., eds., Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science. IOS Press.

No context found.

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-54. IOS Press, 1999.

No context found.

D. Makinson. On a fundamental problem of deontic logic. In H. Prakken and P. McNamara, editors,
EON'98: 4th International Workshop on Deontic Logic in Computer Science. Universita degli Studi di Bologna, 1998.

No context found.

Makinson, D.: \On a fundamental problem of deontic logic". In P. Mc Namara and H. Prakken (eds), Norms, Logics and Information Systems (
EON'98), pages 29-53, Amsterdam: IOS, 1999.

No context found.

D. Makinson. On a fundamental problem of deontic logic. In P. McNamara and H. Prakken, editors, Norms, Logics and Information Systems. New Studies on Deontic Logic and Computer Science, pages 29-54. IOS Press, 1999.

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