慶応義塾大学法学部のゼミナール「伊東乾民事訴訟法研究会」の卒業生の会「乾会」による論文集。今回はテーマを民事訴訟法に限ることなく、現在関心を持っている法律分野について執筆した。.

I CATEGORIES AND PRINCIPLES ii Introductory Remarks The value of linguistics as a cognitive science lies largely in its potential for providing insights ...

This paper proposes a sufficientarian theory with an interval of sufficiency levels. I assume that there are upper and lower bounds of sufficiency and that all well-being levels in between can be considered sufficiency levels. This interval reflects the vagueness of the concept of sufficiency. According to the proposed principle, a distribution is morally better than another if and only if, for each threshold within the interval, the headcount of those below the threshold under the former distribution is smaller than (...) that under the latter distribution. This necessarily leads to incommensurability in moral relations. I argue that such incommensurability makes sufficientarian principles invulnerable to some fundamental objections. (shrink)

The purpose of this study is to investigate a relationship between egalitarian equivalence and envy-freeness in a continuum-agent economy, where tastes vary continuously across individuals. Under efficiency, the two criteria of equity are not compatible, except in the knife-edge case. In particular, when individual utility functions are restricted to the class of Cobb–Douglas-type functions, there exists an efficient, egalitarian-equivalent, and envy-free allocation if and only if all individuals have the same taste over commodities.

Since Condorcet discovered the voting paradox in the simple majority rule, many scholars have tried to investigate conditions that yield “social-preference cycles”. The paradox can be extended to two main approaches. On the one hand, Kenneth Arrow developed a general framework of social choice theory; on the other hand, direct generalizations of the paradox were offered. The motivation and surface meaning of the two approaches are different, as are the assumed background conditions. In this paper, we investigate the relationship between (...) the two approaches by taking a close look at two works, Ferejohn and Fishburn and Schwartz. (shrink)

L’imposition est l’un des principaux sujets de la théorie de la propriété des droits, mais il a pourtant été assez négligé jusque récemment. La communauté académique des philosophes avance de nos jours des arguments pour discuter avec ardeur des types d’imposition qui sont légitimes, s’il en est, et l’on doit beaucoup en ce domaine à l’ouvrage de Liam Murphy et Thomas Nagel The Myth of Ownership. Dans leur ouvrage polémique, les auteurs soutiennent qu’il n’existe pas de droit légitime permettant d’imposer (...) par préemption ni la propriété ni les droits naturels à la propriété et que le processus d’imposition n’empiète certes jamais sur les droits de propriété, qui sont le fruit d’une institution par décret gouvernemental. Murphy et Nagel prennent pour cible principale Richard Epstein qui prône une vue libertarienne ou « libérale classique » contraire à ce propos. Epstein compare l’imposition à une expropriation publique et argumente en faveur de l’impôt sur le revenu. Nous discutons ici la thèse d’Epstein sur la propriété privée, avec laquelle nous nous trouvons en accord quoique moyennant des nuances notables. Nous examinons la théorie étatiste de la propriété de Murphy et Nagel et nous soutenons que leur égalitarisme est surtout le fait d’un présupposé. Nous concluons que l’impôt sur la propriété foncière est la forme d’imposition la plus apte à être légitimée à partir de la perspective libertarienne sur les droits naturels, plus en tous cas que l’impôt sur le revenu et que la taxe sur la valeur ajoutée, formes d’impôt qui sont les plus habituelles. Surtout, nous soutenons qu’il y a là une forme d’imposition que la Constitution du Japon autorise. (shrink)

「語の意味」とは何か?『類語大辞典』の編集・執筆に関わってきた著者が、「意味の本質」「同義・類義・多義」「意味記述の方法」「辞書と意味記述」の4部に渡って、これまで深めてきた考察を明らかにする、「こと ばの意味」の研究に大きく資する一冊。.

The aim of the present paper is to provide an axiomatic analysis of incomplete social judgments. In particular, we clarify the underlying power structure of Arrovian collective choice rules when social preferences are allowed to be incomplete. We propose the concept of quasi-decisiveness and investigate the properties of the collection of quasi-decisive sets associated with an Arrovian collective choice rule. In the course of this, we offer a series of applications.

Suzumura consistency is a necessary and sufficient condition for the existence of a weak-order extension. This paper provides some remarks on collective choice rules that generate Suzumura consistent social preferences. We examine the properties of such collective choice rules by introducing a procedural condition on collective choice rules. As applications of the procedural condition, we first investigate the decisive structure of a Paretian collective choice rule, and then consider the assignment of individual rights. In our analysis, the concept of semi-decisiveness (...) works effectively. (shrink)

It has been shown that the Mere Addition Paradox occurs in a choice-functional approach with Path Independence (Stewart R.T., 2021, Path independence and a persistent paradox of population ethics, Journal of Philosophy, forthcoming). The present study is a three-part response to this finding. First, I show that Path Independence is not an essential property leading to this paradox and that logically weaker properties can get the same result. Second, I present a rationalizable choice function that does not yield the paradox. (...) And third, I argue that menu-dependent relations are nicely examined if Path Independence is relaxed to Property $\alpha $ (or equivalently, Contraction Consistency). (shrink)

This article investigates the relationship among the weak Pareto principle, the strong Pareto principle, and positive responsiveness in the context of voting. First, it is shown that under a mild domain condition, if an anonymous and neutral collective choice rule (CCR) is complete and transitive, then the weak Pareto principle and the strong Pareto principle are equivalent. Next, it is shown that under another mild domain condition, if a neutral CCR is transitive, then the strong Pareto principle and positive responsiveness (...) are equivalent. By applying these results, we obtain a new characterization of the method of majority decision. (shrink)

This paper explores the notion of species-relative critical levels, which is a crucial ethical issue in multi-species population ethics. First, the formal conditions are provided under which there are species-relative critical levels (e.g., the critical level for human beings is different from that for non-human beings). In particular, we find it a salient question of animal ethics whether the existence of a human being is morally better than that of a non-human animal when their utility levels are the same. Subsequently, (...) we illustrate two general classes of multi-species critical-level utilitarian orderings. One class employs species-relative critical levels, which entails either the animal repugnant conclusion or the animal sadistic conclusion. The other employs species-relative critical levels plus species-lexical ordering. Although it can avoid both the animal repugnant conclusion and the animal sadistic conclusions, it has the problem of speciesism. (shrink)

This paper offers a new insight on the Condorcet Jury Theorem (CJT) in the theory of epistemic democracy. This theorem states that democratic decision-making leads us to correct outcomes under certain assumptions. One key assumption is the ‘independence condition’, which requires that voters form their beliefs independently when they vote. This paper examines the role of an opinion leader as an informational source, which potentially violates independence. We demonstrate that voters’ beliefs may be correlated in the presence of the leader, (...) and that the CJT can fail if the leader’s opinions are reliable. This leads us to the following paradoxical observation: for epistemic democracy, good leaders may be bad, while bad leaders may be good. (shrink)

Bioethics, Volume 36, Issue 4, Page 445-452, May 2022.

Arrow’s impossibility theorem states that if an aggregation rule satisfies unrestricted domain, weak Pareto, independence of irrelevant alternatives, and collective rationality, then there exists a dictator. Among others, Arrow’s postulate of collective rationality is controversial. We propose a new axiom for an aggregation rule, decisiveness coherence, which is weaker than collective rationality. It is shown that given the Arrovian axioms other than collective rationality, a dictatorship arises if and only if decisiveness coherence is satisfied. Moreover, we introduce weak versions of (...) decisive coherence and examine these implications. (shrink)

This paper shows that weak Pareto and strong Pareto are equivalent under continuity and strong quasi-concavity. We use a framework that incorporates welfare as well as non-welfare information.

In this paper, we explore the stability of the aggregation procedure of individual preferences. In particular, we propose the stability under the addition of social preference, which is a normative property of democratic collective decision making. We establish impossibility and possibility theorems for non-dictatorial aggregation procedures.

The Trends in International Mathematics and Science Study found that even though children from all East Asian countries outperformed American children, American students reported higher self-evaluation of their math and science abilities than did students from East Asian countries such as China, Korea, and Japan (Mullis, Martin, Gonzalez, & Chrostowski, 2004). Such cross-cultural differences in self-appraisal fit the stereotype of the modest East Asian and contribute to the received view that East Asians have less positive self-concepts than Americans. This view (...) was summarized recently by Heine, Lehman, Markus, and Kitayama (1999) as follows: ‘‘The need for positive self-regard, as it is currently conceptualized, is not a universal, but rather is rooted in significant aspects of North American culture’’ (p. 766; but cf. Sedikides, Gaertner, & Vevea. (shrink)

いかなる方向に臨めば日本が文化的小児病から脱することができるのか、そしてその果てに日本文明の成熟をすら望みうるのか(「西欧の自己懐疑と日本の自己放棄」より)―保守的自由主義の源流、エドマンド・バーク、 「大衆」に関して、それを「奇怪」なる存在と捉えていたキルケゴール、民主主義批判をしたニーチェ...など十五人の思想家たちの言説を、私たちが今を生き抜くための精神的な糧にしようとする画期的な書、待望の文 庫化。.

仏教には本来、社会倫理的な実践が大きな要素として備わっていた。近代的な宗教観のもとで見落とされがちだった日本仏教の倫理性・社会性の側面が、現代社会の中で再び顕わになりつつある。本書は、「正法」理念に着 目しながら、日本仏教の実践思想の系譜を捉え直し、宗派主義の枠を超えた新しい日本仏教史像を描く試みである。.

Population axiology includes two major arguments. The first is the repugnant conclusion, which was originally formulated by Derek Parfit to criticize total utilitarianism. The second is the sadistic conclusion. In this study, I demonstrate that no additively separable principle can avoid both repugnant and sadistic conclusions if individual moral values have no upper bound. This impossibility holds not only for utilitarian principles but also for any population principles that guarantee the separability of people’s well-being. I emphasize the importance of examining (...) non-separable principles in population ethics. (shrink)

We examine a general class of variable-value population principles. Our particular focus is on the extent to which such principles can avoid the repugnant and sadistic conclusions. We show that if a mild limit property is imposed, avoidance of the repugnant conclusion implies the sadistic conclusion. This result generalizes earlier observations by showing that they apply to a substantially larger class of principles. Our second theorem states that, under the limit property, the axiom of mere addition also conflicts with avoidance (...) of the repugnant conclusion. This result is a consequence of a similar observation that appears in the earlier literature. (shrink)

This paper aims to reexamine the axiom of the independence of irrelevant alternatives in the theory of social choice. A generalized notion of independence is introduced to clarify an informational requirement of binary independence which is usually imposed in the Arrovian framework. We characterize the implication of binary independence.

This article considers social choice theory without the Pareto principle. We revisit the trade-off theorem developed by Campbell and Kelly (Econometrica 61:1355–1365, 1993) and generalize their result. By introducing an alternative measure of decisive structure, a dominance relation, we show that if a social welfare function dominates another social welfare function, then the number of pairs of alternatives which social ranking is independently of individual preferences under the former is not more than that under the latter. Moreover, we offer two (...) applications of our main result. (shrink)

This paper is concerned with the problem of group decision making. We introduce the notion of a collective system rule. A collective system rule maps each preference profile to a group-preference system, which is a collection of social preferences on the subsets of the alternatives. By formulating the Arrovian conditions, we show the Arrow-type impossibility theorems. We also discuss how our approach is related to the standard group decision-making process.

In this paper, the independence of irrelevant alternatives and the Pareto principle are simultaneously weakened in the Arrovian framework of social choice. Moreover, we also relax transitivity of social preferences. We show that impossibility remains under weaker versions of Arrow’s original conditions. Our results complement the recent work by Coban and Sanver (Soc Choice Welf 43(4):953–961, 2014).

This paper is concerned with social choice without completeness of social preference. Completeness requires that pairs of alternatives are perfectly comparable. We introduce the concept of minimal comparability, which requires that for any profile, there is some comparable pair of distinct alternatives. Complete silence should be avoided according to this condition. We show that there exists no normatively desirable aggregation rule satisfying minimal comparability.

This paper examines the concept of ‘tsunami-tendenko,’ a guideline suggesting that individuals prioritise their own safety over aiding others during large-scale disasters. Kodama defends tsunami-tendenko against accusations of egoism by arguing that the principle can be justified ethically on consequentialist (or more precisely, utilitarian) grounds. Kodama asserts that attempting to assist others during such disasters heightens the risk of ‘tomo-daore,’ where both the rescuer and the victim may perish. He claims that having people focus solely on saving themselves can maximise (...) the overall number of lives saved. However, we challenge Kodama’s assertion that utilitarianism inherently favours tsunami-tendenko over mutual assistance during disasters. Instead, this paper proposes an alternative ethical foundation for tsunami-tendenko grounded in the ‘antiextinction principle,’ which prioritises minimising the potential for catastrophic outcomes. When considering the ethics of responding to disaster, it is important to distinguish between maximising the number of lives saved (utilitarianism) and minimising the risk of tomo-daore (antiextinction principle). This distinction may be overlooked if the distribution of probabilities is not considered. We conclude that the antiextinction principle aligns more naturally with tsunami-tendenko, emphasising the avoidance of catastrophic outcomes—a concern not always addressed by utilitarianism. Therefore, tsunami-tendenko should be regarded as a societal guideline aimed at preserving community sustainability by averting total destruction. (shrink)

In this study, we propose a new direction of research on the axiomatic analysis of approval voting, which is a common democratic decision method. Its novelty is to examine an infinite population setting, which includes an application to intergenerational problems. In particular, we assume that the set of the population is countably infinite. We provide several extensions of the method of approval voting for this setting. As our main result, axiomatic characterizations of the extensions are offered by revealing a direct (...) link between approval voting and the Borda rule. The characterized methods are natural extensions of the standard approval voting method for the finite-population case and are regarded as minimum requirements for other possible infinite-population extensions, which are reasonably democratic. (shrink)

This paper examines collective decision-making with an infinite-time horizon setting. First, we establish a result on the collection of decisive sets: if there are at least four alternatives and Arrow’s axioms are satisfied on the selfish domain, then the collection of decisive sets forms an ultrafilter. Second, we impose generalized versions of stationarity axiom for social preferences, which are substantially weaker than the standard version. We show that if any of our generalized versions are satisfied in addition to Arrow’s axioms, (...) then some generation is dictatorial. Moreover, we specify a very weak stationarity axiom that guarantees a possibility result. (shrink)

This paper examines social choice theory with the strong Pareto principle. The notion of conditional decisiveness is introduced to clarify the underlying power structure behind strongly Paretian aggregation rules satisfying binary independence. We discuss the various degrees of social rationality: transitivity, semi-transitivity, the interval-order property, quasi-transitivity, and acyclicity.