Spatial evolutionary game theory explains how cooperative traits can survive the intense competition in biological systems. If the spatial distribution allows cooperators to interact with each other frequently, the benefits of cooperation will outweigh the losses due to exploitation by selfish organisms. However, for a cooperative behavior to get established in a system, it needs to be found initially in a sufficiently large cluster to allow a high frequency of intracooperator interactions. Since mutations are rare events, this poses the question (...) of how cooperation can arise in a biological system in the first place. We present a simple model which captures two concepts from genetics that can explain how evolution overcomes the emergence problem. The first concept is, often in nature, a gene may not express its phenotype except under specific environmental conditions, rendering it to be a “silent” gene. The second key idea is that a neutral gene, one that does not harm or improve an organism’s survival chances, can still spread through a population if it is physically near to another gene that is positively selected. Through these two ideas, our model offers a possible solution to the fundamental problem of emergence of cooperation in biological systems. (shrink)

Positive frequency dependent selection is a natural selection regime where the fitness of a phenotype increases with its frequency in the population. Examples can be typically found in the spread of disease tolerance strategies in a population. A characterizing feature of PFDS is that the focal allele may experience favorable selection only when it becomes more frequent in the population, while being selected against when it is rare. In this paper, by applying a solution concept from evolutionary game theory, we (...) hypothesize that the process of emergence of such alleles triggers selection for silence, where the emergence of alleles that can stay unexpressed for a period of time will be favored by selection forces. We illustrate our hypothesis using a mathematical model of a population of single locus diploid organisms with two alleles where a single mutant of an allele that experiences positive frequency dependent selection appears in a population where the other allele is a dominant. The model results show that the longer the silence interval of the new mutant before its expression, the better its chances of getting fixed in the population. However, this effect will be observable only to a certain limit after which further increase in the interval will not have an effect on the expected fixation rate. Two divergences from the simple scenario are also investigated: the nonsynchronous expression of the focal allele and its emergence in a spatial grid limited by a migration bottleneck. In all cases, it is shown that there is an evolutionary pressure inherent in the dynamics of positive frequency dependent selection on the genes to have a delayed expression. It is hypothesized that the regulation systems of such traits will be under selection for either internal silencing mechanisms or to be triggered by an external environmental condition. (shrink)

Since Kit Fine presented his counter-examples to the standard versions of the modal view, many have been convinced that the standard versions of the modal view are not adequate. However, the scope of Fine's argument has not been fully appreciated. In this paper, I aim to carry Fine’s argument to its logical conclusion and argue that once we embrace the intuition underlying his counter-examples, we have to hold that properties obtained, totally or partially, by application of logical operations are not (...) essential to non-logical entities. I also demonstrate that most of the post-Finean versions of the modal view, which were developed to accommodate Fine’s counter-examples, entail that such properties are essential to the entities, and so fail to capture the notion of essence at issue in Fine's counter-examples. Additionally, I explore the consequence of my argument for Fine’s proposed logic of essence. The logic turns out to be inadequate in its present shape as it represents such properties to be essential to the entities. I conclude by developing a modification to the logic to overcome the shortcoming. (shrink)

Since Kit Fine published his famous counter-examples to the modal account of essence, numerous modalists have proposed to avoid the counter-examples by revising the modal account. A sophisticated revision has been put forward by Fabrice Correia. Drawing on themes from Prior’s modality, Correia has introduced a nonstandard conception of metaphysical modality and has proposed to analyze essence in its terms. He has claimed that the analysis is immune to Fine’s counter-examples. In this paper, I argue that there are counter-examples supported (...) by the very intuition underlying Fine’s counter-examples, which are not accommodated by Correia’s account. If my argument is sound, then Correia has not been successful in his defense of modalism. An important corollary of my argument will be that Fine’s consequential conception of essence needs to be modified if it is to capture his own intuitive notion of essence. (shrink)

One common objection against the Principle of Sufficient Reason is that it leads to a highly counterintuitive position, namely, necessitarianism. In this paper, drawing on Avicenna’s modal theory, I differentiate between two versions of necessitarianism: strong necessitarianism and weak necessitarianism. I argue that the modal intuition driving this objection pertains to strong necessitarianism, while the Principle of Sufficient Reason, at most, leads to weak necessitarianism.

The Muʿtazilī theologians, particularly the later Imāmī ones, developed numerous interesting arguments against divine command theory. The arguments, however, have not received the attention they deserve. Some of the arguments have been discussed in passing, and some have not been discussed at all. In this article, I aim to present and analyse the arguments. To that end, I first distinguish between different semantic, ontological, epistemological, and theological theses that were often conflated in the debate, and examine the logical relation among (...) them. Then I go over the Muʿtazila's arguments determining, among other things, which of the theses was targeted by each argument. In presenting the arguments, I focus mainly on the late kalām period, the period falling roughly between the thirteenth and fifteenth centuries of the common era, as the arguments were at their most sophisticated level by this time. (shrink)

Hale has argued that logical necessities are absolute in the sense that there is no competing kind of modality under which they may be false. In this paper, I argue that there are competing kinds of modality, which I call “essentialist modalities,” under which logical necessities may be false. Since it is counter-intuitive to say that logical necessities are not absolute, my argument, if correct, shows that Hale’s characterization of absolute necessity does not adequately capture the intuitive notion of absolute (...) necessity. Then, a qualified version of Hale’s characterization of absolute necessity is proposed. On the qualified version, the absoluteness of logical necessities is no longer defeated by essentialist possibilities. (shrink)

More general form of -neutrosophic ideal is introduced, and their properties are investigated. Relations between -neutrosophic ideal and )-neutrosophic ideal are discussed. Characterizations of )-neutrosophic ideal are discussed, and conditions for a neutrosophic set to be an )-neutrosophic ideal are displayed.

A new lifetime distribution, called exponential doubly Poisson distribution, is proposed with decreasing, increasing, and upside-down bathtub-shaped hazard rates. One of the reasons for introducing the new distribution is that it can describe the failure time of a system connected in the form of a parallel-series structure. Some properties of the proposed distribution are addressed. Four methods of estimation for the involved parameters are considered based on progressively type II censored data. These methods are maximum likelihood, moments, least squares, and (...) weighted least squares estimations. Through an extensive numerical simulation, the performance of the estimation methods is compared based on the average of mean squared errors and the average of absolute relative biases of the estimates. Two real datasets are used to compare the proposed distribution with some other well-known distributions. The comparison indicates that the proposed distribution is better than the other distributions to match the data provided. (shrink)

A main function of common natures in Avicenna’s metaphysics is supposed to be providing an objective ground for the categories. Thus, it is commonly assumed that in his metaphysics things are objectively divided into the categories into which they are because members of each category share the same common nature. However, common natures cannot perform the function unless they are shared, in a real sense of the word, by the members of the respective categories, and it is not clear at (...) all in what real sense Avicenna took common natures to be shared by them. On the one hand, he rejected Platonic and Aristotelian realisms about common natures, the two standard accounts of how common natures are shared by their instances. On the other hand, it is unclear that his alternative account(s) of common natures renders them genuinely common. The primary goal of this paper is to examine whether Avicenna’s common natures can provide an objective ground for the categories. It considers various interpretations of Avicenna's account and argues that they are either incorrect interpretations of Avicenna or do not render common natures genuinely common. It concludes with proposing to look elsewhere in Avicenna’s system to find the objective ground. (shrink)

One of the arguments of the realists to prove the existence of universals in the external world is “abstract reference”. According to this argument, there are many true sentences in a language which apparently relates to universals. In the realists’ view, truth of these sentences can be explicated only when universals exist in the external world. On the basis of his “degree of language” theory, Carnap has criticized the above-mentioned argument and demonstrated that delusion of the existence of universals has (...) resulted from the confusion in regard to different degrees of language. In his view, those sentences concerning to universals are in fact second-order sentences which assert properties with regard to some first-order sentences. But Carnap’s theory suffers from two main objections: firstly, his theory is not successful in the elimination of reference to universals, because on the basis of his theory, only reference to non-linguistic universals would be eliminated but reference to linguistic universals continue to survive. Secondly, supposing that Carnap’s theory is true, translation of the sentences in question would be extremely difficult and complicate. So Wilfred Sellars attempts to response the two objections, and thus, to present a reformed version of Carnap’s theory. In the present article, the author first explains Carnap’s theory; then, it presents the relevant objections; and finally, it offers Sellars’ reformed version of Carnap’s theory. (shrink)

First published in 1985, this title includes contributions from leading economists and addresses many seminal aspects of Keynes' work and methods. This revival will be of particular interest to lecturers and advanced students of economics.

First published in 1985, this title includes contributions from leading economists and addresses many seminal aspects of Keynes' work and methods. This revival will be of particular interest to lecturers and advanced students of economics.

Characterizations of an (∈, ∈)-neutrosophic ideal are considered. Any ideal in a BCK/BCI-algebra will be realized as level neutrosophic ideals of some (∈, ∈)-neutrosophic ideal. The relation between (∈, ∈)-neutrosophic ideal and (∈, ∈)-neutrosophic subalgebra in a BCK-algebra is discussed. Conditions for an (∈, ∈)-neutrosophic subalgebra to be a (∈, ∈)-neutrosophic ideal are provided. Using a collection of ideals in a BCK/BCI-algebra, an (∈, ∈)-neutrosophic ideal is established. Equivalence relations on the family of all (∈, ∈)-neutrosophic ideals are introduced, and (...) related properties are investigated. (shrink)

Social entrepreneurship, individual activities with a social objective, is used in this study as a conceptual tool for empirically examining farmers’ participation in alternative food networks. This study verifies whether their participation is driven by the social entrepreneurship dimension to satisfy social and environmental needs. We develop a more inclusive view of how social entrepreneurship is present among farmers participating in AFNs by using a behavioural approach based on three main psychological constructs: attitude, objective, and behaviour. The empirical results show (...) that two types of farmers participate in AFNs. One type is closer to commercial entrepreneurs; the main attitudes and objectives affecting their behaviour are oriented toward profit maximization and farm progress. The second type is closer to social entrepreneurial activity; the main objectives affecting their behaviour are oriented towards satisfying social and environmental needs. The study’s results offer implications and suggest recommendations concerning social entrepreneurial practices and the motivations of the farmers who participate in AFNs. (shrink)

The notion of int-soft ideal in a pseudo MV -algebra is introduced, and related properties are investigated. Conditions for a soft set to be an int-soft ideal are provided. Characterizations of int-soft ideal are considered. The extension property for implicative int-soft ideal is established.

The focus of this paper is to develop a comprehensive conceptual framework for the relationship between internal employer brand image and talent retention. An extensive and semi-systematic literature review identified a number of antecedents and consequences that have been empirically tested in various cutting-edge research studies that were conducted around the world. The existing literature is reviewed using a topical approach, and 66 research studies, most recent from various repositories, were carefully chosen and reviewed based on the criteria. Such studies (...) have been discerned and synthesized in order to establish a complete and accurate understanding of the phenomenon. Finally, a comprehensive and relatively rich conceptual framework has been proposed for future empirical explanations in various social settings via prospective research. (shrink)

In this article we consider certain elements of the normative theory of Jürgen Habermas in the light of the proposals of Bruce Ackerman, with a view to strengthening a concept of deliberative democracy applied to the legitimation of juridical rules. We do not construct a hierarchy of the two positions, but seek to bring together certain elements to achieve a common project. As the starting point for examining the work of the two authors, we take the scheme proposed by Habermas (...) in Faktizität und Geltung. In this connection, through the work of Ackerman, we intend to fill in some of the gaps that Habermas appears to have left in the theory of radical democracy applied to the law. The work of Ackerman can make a significant contribution to deliberative democracy, to the discourse principle that Habermas defines, and to the contractualist theories from a liberal perspective. The study of these contributions makes possible a critical judgment that enables the legitimation of juridical rules carried out by Habermas to acquire greater practicity. In examining the epistemological status of juridical science and law, we attempt to determine the weight and the performance of normative democracy. In Tarr's view, it is a matter for philosophers to examine direct democracy and its desirability. (shrink)

... all probability, Plato's own statement; made indeed to be read by friends in Syracuse in explanation of the role he had played ...

Accounting for the evolutionary origins of morphological novelty is one of the core challenges of contemporary evolutionary biology. A successful explanatory framework requires the integration of different biological disciplines, but the relationships between developmental biology and standard evolutionary biology remain contested. There is also disagreement about how to define the concept of evolutionary novelty. These issues were the subjects of a workshop held in November 2009 at the University of Alberta. We report on the discussion and results of this workshop, (...) addressing questions about (i) how to define evolutionary novelty and understand its significance, (ii) how to interpret evolutionary developmental biology as a synthesis and its relation to neo-Darwinian evolutionary theory, and (iii) how to integrate disparate biological approaches in general. (shrink)

The present article commences analyzing the origins and influences of the religious discourse on the configuration of the modern constitutional discourse and the contributions of the jus-positivism in the consolidation of this sacred-civil language. The second issue is the definition of the U.S. Constitution as a mixed and not as a democratic constitution, with regard to the influences of Plato, Aristotle, Cicero and Polybius to the Drafters of the first modern constitutional text; stability and equilibrium took preference over democracy in (...) a wide sense. I also analyze how the Drafter’s decision has conditioned the modern constitutional system up to the present. (shrink)

Locke is the first English philosopher to be considered in this series, and that fact of itself is worthy of attention. Philosophy, of course, like science, knows no frontiers and no national boundaries. Yet it is true to say that Locke’s contribution to philosophy is typically and peculiarly English. His moderation, his emphasis upon experience, his tolerant spirit of compromise, his dislike of mystical extravagance and of metaphysical speculation, even that elusive quality of his which people call his “common sense”, (...) are English traits. His very defects, illogicality leading to inconsistency and an awkward disorderliness of thought so abhorrent to the. (shrink)