Reiner Schürmann speaks of the end of Western metaphysics as the end of a mode of thinking that relies on an overriding metaphysical principle that establishes the economies that provide the space for permissible and impermissible actions. In its wake, he proposes a project of an-archy, of living without the reliance to the domination of one central metaphysical concept, but rather of kata physin, of “following the way things enter into mutual relations.” Kenneth Schmitz, in reacting to Schürmann, points out (...) that there are elements in Christian thought that can also provide new patterns of thought and action at the twilight of the end of metaphysics, namely, the notions of: charity, the Trinity, and mystery. I shall take up the second suggestion of Schmitz and attempt to articulate what the Christian notion of the Trinity can contribute to our understanding of thought and action after the end of metaphysics. I argue that through the theological detour of Thomistic Trinitarian thought, we can chart out new patterns of thought and action, specifically on the notion of the tri-personality of the Trinity, leading to the analogical understanding of persons-as-relations. Such a consideration not only provides a sharp rebuttal to Schürmann in his understanding of “hard unity” in terms of metaphysical principles, but it also helps us understand the place of man in the contemporary world: one of charitable relationality. (shrink)

Evaluates trade-offs and uncertainties inherent in achieving sustainable energy, analyzes the major energy technologies, and provides a framework for assessing policy options.

Spontaneous eye blink rate has been linked to attention and memory, specifically working memory. sEBR is also related to striatal dopamine activity with schizophrenia and Parkinson’s disease showing increases and decreases, respectively, in sEBR. A weakness of past studies of sEBR and WM is that correlations have been reported using blink rates taken at baseline either before or after performance of the tasks used to assess WM. The goal of the present study was to understand how fluctuations in sEBR during (...) different phases of a visual WM task predict task accuracy. In two experiments, with recordings of sEBR collected inside and outside of a magnetic resonance imaging bore, we observed sEBR to be positively correlated with WM task accuracy during the WM delay period. We also found task-related modulation of sEBR, including higher sEBR during the delay period compared to rest, and lower sEBR during task phases that place demands on visual attention. These results provide further evidence that sEBR could be an important predictor of WM task performance with the changes during the delay period suggesting a role in WM maintenance. The relationship of sEBR to DA activity and WM maintenance is discussed. (shrink)

This article addresses the way in which therapeutic practice in an English prison creates conditions whereby both prisoners and prison officers are caught up in networks and relationships of power that contribute to the constitution of particular subjects. The development of therapeutic practice, in relation to prisons and probation, is described and contextualised. Subsequently, the practices of group therapy in operation at Grendon prison - a rather unique institution built on principles of therapeutic community – are analysed with a focus (...) on five ”practices of moulding,” namely, naming, confession, assessment and surveillance, tolerance and participation. The argument that psychotherapy, under conditions of imprisonment, is a form of repression or social control is discussed and dismissed as too simple a model to account for the relations of power and constitutive practices that effect all participants, not only prisoners. Members of staff, as well as prisoners, are shown to be caught up in the disciplinary web. Discipline, as opposed to control, is advocated as a more appropriate concept for understanding therapeutic practices in prison. The work of Thomas Mathiesen, on the concept of synoptic power, is introduced to help illustrate these dynamics. The article represents a shift in my own thinking, from scepticism to a pragmatic idealist position, that creates space for institutions like Grendon to be imagined as potential least worst options for people convicted of offences and obliged to serve “time”. It is my hope, argued for in the article, that Grendon can be conceived of as a “visionary space” with emancipatory potential. (shrink)

This book is about what makes law possible. A stranger to contemporary legal practice might think such a book unnecessary, but the eight authors of this book share the view that what makes law possible is under siege today. The authors also share the hope that by exploring how law is a humanistic practice that involves whole persons, the siege will be reversed. The pathbreaking work of University of Michigan Law professor Joseph Vining provides the authors' focus for their varied (...) analyses of how law works not through force but, instead, through affinity.Vining's four books and other writings, spanning four decades, reveal the hidden connections by which men and women freely create and sustain a world of meaning through the phenomena we associate with law. Drawing on legal philosophy, theology, musicology, and other humanistic disciplines, the authors join Vining in discovering how law is, as Vining has written, “evidence of view and belief far stronger than academic statement or introspection can provide.” Law as Vining and the other authors reveal it is evidence of our better selves, not of the totalizing and brutalizing selves humans are capable of becoming, sometimes even under cover of law.In addition to the three editors, the book's authors are Joseph Vining, Rev. John McCausland, Hon. John T. Noonan, Jr., Steven Smith, and James Boyd White.Lawyers and all who care about law, the human future, and what human freedom can do to connect person to person as valued will find much to ponder in the chapters of this book. By avoiding jargon and the cliché, the authors follow Vining's lead in illuminating the deep springs of law's vitality and authority. (shrink)

The American Journal of Bioethics, Volume 12, Issue 5, Page 13-14, May 2012.

Perhaps the most difficult part of the famous inscription from Heraclea is the opening section of the extant text, where from a given form of procedure it is required to determine the subject matter. A solution of this puzzling problem, which I proposed some months ago, has recently been made the subject of an interesting article in this journal by Dr. E. G. Hardy. Mr. Hardy has long been engaged in this field, and has rendered much useful service. In this (...) article, however, he seems to be interested in my views chiefly in their relation to his own theory. This is apparent in his agreements with me. For example, one aim of my study was to identify the professiones of Cicero's letters ad Att. xiii. 33, 1, and ad Fam. xvi. 23, 1, with those provided for in the first section of the inscription. It appeared that the returns mentioned by Cicero were registrations of property, that they were to be made yearly, and that they had their prototype in the annual property census of Egypt. It also seemed clear that Caesar's recensus populi of 46 was modelled on the Egyptian kατ' oίkíαm άπoγραφήiKíαν. With these preliminary conclusions Mr. Hardy is not unwilling to agree. He even goes so far as to say that I have made a good case for ‘a new system of professiones somehow relating to property and introduced in 46.’ He thinks too that the settlement of the frumentations as a part of a more comprehensive legislative scheme would be most appropriate. So far so good, but when it comes to the vital point of admitting a connection between these matters and vv. 1–19 of the Tablet he draws back as if from some fatal step. (shrink)

That Jefferson execrated Plato in an 1814 letter to friend John Adams. In it, he expresses an unsympathetic, hostile view of Plato’s Republic, and the reasons are several. Nonetheless, Plato’s views on what makes government fundamentally sound are, at base, remarkably similar to Jefferson’s both in substance and sentiment, so much so that it is inconceivable to think that Plato’s Republic had little effect on Jefferson’s political thinking. That makes his execration of Plato difficult to understand. This (...) paper is an attempt to show that Jefferson, despite the tenor of his letter to Adams, had much more than a dilettante’s grasp of the political content of Plato’s major work. Jefferson was very likely quite familiar with the work, since his own political philosophy assimilates key substratal Platonic political principles of good, stable governing. His disavowal of the work and execration of Plato, then, is due to a constellation of other factors: Adams’s feelings toward Plato, Jefferson’s views on the corruptions of Jesus’s teachings, his deep-dyed detestation of metempiricism, his view that Plato was an unoriginal thinker, and strong disagreement with Plato’s means to instantiate substratal political principles. (shrink)

Plato noticed a sizeable problem apropos of establishing his republic—that there was always a ready pool of zealous potential rulers, lying in wait for a suitable opportunity to rule on their own tyrannical terms. He also recognized that those persons best suited to rule, those persons with foursquare and unimpeachable virtue, would be least motivated to govern. Ruling a polis meant that those persons, fully educated and in complete realization that the most complete happiness comprises solitary study of things unchanging, (...) would have to compromise their happiness for the wellbeing of their polis and of the people in it. Plato’s solution, in effect that the aristoi would merely recognize their duty to sacrifice personal happiness for the happiness of the polis, has perplexed and continues today to perplex scholars. Like Plato, Jefferson recognized that there was always a pool of eager sharks, ready to govern. His republicanism, comprising a ward system and general education, was founded on the fullest participation of its citizenry, suitably educated and a governing aristoi. The true aristoi, the “natural aristoi”, are the intelligent and virtuous and that government is best which allows for a “pure selection” of the natural aristoi into the governing offices. Nonetheless, as Jefferson’s own life shows, non-parochial governing meant being rent from domestic tranquility, being forced to leave behind one’s personal affairs to decay, and being tossed willy-nilly into the coliseum of nonstop political wrangling. Why would anyone, particularly one wanting to be happy, wish to govern? Thus, Jefferson faced the same problem that Plato faced. How could a state be structured so that the wisest and most virtuous would be motivated to rule? In this paper, I argue that Jefferson, in full recognition of the problem of encouraging the most intelligent and virtuous to govern, the problem of public service, offers a solution that is remarkably Platonic. (shrink)

In this paper, the authors have detected a new effect in the area of geomagnetism, related to the behavior of a magnetic dipole freely floating on water surface. An experiment is described in the present paper in which a magnetic dipole fixed upon a float placed on non- magnetized water surface undergoes displacement along with reorientation caused by fine structure of the earth's magnetic field. This fact can probably be explained by secular decrease of the earth's major dipole moment. Further, (...) a detailed study of the phenomenon may create interesting premises for its practical use, particularly for the analysis of fine structure of geomagnetic field and its time-dependent anomalies. A strange behavior of some sea fish species prior to strong earthquakes may be explained if the fish are assumed as 'live magnetic dipoles'. (shrink)

This paper is an examination of several of Thomas Jefferson's philosophical vignettes in his Notes on the State of Virginia. I begin with some thoughts on the structure of the book. I then turn to several of Jefferson's intriguing philosophical vignettes, concerning the aesthetic, natural explanation, Indians, blacks, education, religion, husbandry, and war. I end with some thoughts on what those vignettes tell us about Jefferson's philosophical frame of mind at the writing of his Notes.

Animals depleting one patch of resources must decide when to leave and switch to a fresh patch. Foraging theory has predicted various decision mechanisms; which is best depends on environmental variation in patch quality. Previously we tested whether these mechanisms underlie human decision making when foraging for external resources; here we test whether humans behave similarly in a cognitive task seeking internally generated solutions. Subjects searched for meaningful words made from random letter sequences, and as their success rate declined, they (...) could opt to switch to a fresh sequence. As in the external foraging context, time since the previous success and the interval preceding it had a major influence on when subjects switched. Subjects also used the commonness of sequence letters as a proximal cue to patch quality that influenced when to switch. Contrary to optimality predictions, switching decisions were independent of whether sequences differed little or widely in quality. (shrink)

In a letter to Benjamin Rush, Jefferson includes a syllabus—a comparative account of the merits of Jewish morality, ancient philosophy, and the precepts of Jesus. Using the syllabus as a guide, this paper is a critical examination of the influence of ancient ethical and religious thinking on Jefferson’s ethical and religious thinking—viz., Jefferson’s views of the ethics and religion of the Hebrews, the ancient philosophers, and Jesus.

Roman Frigg and others have developed a general epistemological argument designed to cast doubt on the capacity of a broad range of mathematical models to generate “decision relevant predictions.” In this article, we lay out the structure of their argument—an argument by analogy—with an eye to identifying points at which certain epistemically significant distinctions might limit the force of the analogy. Finally, some of these epistemically significant distinctions are introduced and defended as relevant to a great many of the predictive (...) mathematical modeling projects employed in contemporary climate science. (shrink)

Much epistemological theorizing is the attempt to specify what makes for meritorious cognition, but epistemologists have not, despite meritorious effort, achieved unity when it comes to picking out the feature and principles that are distinctive of epistemic normativity. In this essay we explain why this is the inevitable outcome. We isolate important but overlooked variations in the link between epistemological theorizing and the idea of epistemic unification, and then argue that much epistemological theorizing is misguided because it aims toward complete (...) epistemic unification when only partial epistemic unification, at best, is possible. But our arguments — based on work in moral epistemology and philosophical psychology — stop short of epistemological eliminativism, and thus we stake out a middle ground between philosophers such as Descartes, the earlier Alston, Audi, and the earlier BonJour on one hand and Rorty, Fish, and Patricia Churchland on the other. (shrink)

Scholars today are divided on the motivation behind what is often called Jefferson’s “moral agrarianism”. On the one hand, some scholars take Jefferson at his word when he mentions that agrarianism is a moral vision. For these individuals, Jefferson’s agrarianism is a moral vision and an indispensible part of the good life. On the other hand, other scholars maintain that Jefferson’s moral agrarianism is merely a bit of propaganda that insidiously sheaths a political or economic ideal. (...) For them, Jefferson is through and throughout a politician, and expressions of agrarianism as a moral ideal amount to mere cant. In this paper, I examine arguments for and against Jefferson’s moral agrarianism. I defend the position that Jefferson was an aboveboard moral agrarianist and that the ideal of agrarianism was not just one that was suited for Americans, given their surfeit of land and want of laborers, but an ideal that also applied universally. I end with thoughts on Jefferson’s recognition of the rise of manufacturing in American cities throughout his life. (shrink)

1. In her latest book (Jefferson, 2022), “Are Mental Disorders Brain Disorders?”, Anneli Jefferson (AJ) argues that mental disorders can be considered brain disorders when they involve brain dysfun...

When talk of philosophy of pedagogy comes up today, it is common to hear the names of Aristotle, Thomas Jefferson, John Dewey, or Paulo Freire, but the name of Paul Goodman, who campaigned vigorously for pedagogical reform much of his life, is seldom mentioned. In spite of neglect of his work, Goodman had much to say on pedagogical practice that is rich, poignant, and relevant today. In consequence, it is unfortunate that he is seldom read and discussed today. This (...) essay is an attempt to fill in the gap in the scholarship. I begin by presenting an elaboration of Goodman's key insights. I then offer a critical analysis of those pedagogical insights. (shrink)

Eusociality is the form of animal social organization with a reproductive division of labor, most prominently known from ants and bees. Here I ask the question why this enormously successful form of social organization is missing in the largest and most diverse group of vertebrates, the teleost fishes. I first briefly review the phylogenetic distribution and likely evolutionary origins of eusociality. Then, after an equally very brief review of the diverse life history strategies of teleosts, I conclude that it is (...) not the lack of evolutionary pre-adaptations which is keeping teleosts from becoming eusocial. Rather, I argue, that the absence of eusocial fish is caused by a number of differences between aquatic (chiefly marine) and terrestrial ecosystems: (1) Greater offspring dispersal in aquatic ecosystems reduces the role of kin-selection. (2) Lesser predictability of the environment at larger timescales in marine ecosystems disfavors eusociality. (3) A briefer impact of resource pulses in aquatic ecosystems will cause less evolutionary pressure towards cooperation, and eventually eusociality. Finally, I conclude by predicting that the most likely places to find eusocial fishes will be the deep-water regions of the ocean and the African rift lakes. (shrink)

The excessive and unsustainable exploitation of our marine resources has led to the promotion of marine reserves as a fisheries management tool. Marine reserves, areas in which fishing is restricted or prohibited, can offer opportunities for the recovery of exploited stock and fishery enhancement. This study examines the impact of the creation of marine protected areas, from both economic and biological perspectives. The consequences of reserve establishment on the long-run equilibrium fish biomass and fishery catch levels are evaluated. We (...) include reserve size as control variable to maximize catch at equilibrium. A continuous time model is used to simulate the effects of reserve size on fishing catch. Fish movements between the sites is assumed to take place at a faster time scale than the variation of the stock and the change of the fleet size. We take advantage of these two time scales to derive a reduced model governing the dynamics of the total fish stock and the fishing effort. Simulation results suggest that the establishment of a protected marine reserve will always lead to an increase in total fish biomass, an optimal size of a marine reserve can achieve to maximize the catch at equilibrium. (shrink)

Intuitions play an important role in contemporary philosophy. It is common for theories in epistemology, morality, semantics and metaphysics to be rejected because they are inconsistent with a widely and firmly held intuition. Our goal in this paper is to explore the role of epistemic intuitions in epistemology from a naturalistic perspective. Here is the question we take to be central: (Q) Ought we to trust our epistemic intuitions as evidence in support of our epistemological theories? We will understand this (...) question as employing an epistemic ‘ought’ – insofar as we aim at developing a correct epistemological theory, ought we to trust our epistemic intuitions as evidence for or against our epistemological theories? As it stands, (Q) needs further clarification. Whether something is trustworthy is relative to what (a) what it is and (b) what we’re asking it to do. Sam might trust Marie but not George to care for his children, while he might trust both to care for his pet fish. So in order to address (Q), we first need to explore two questions: What are epistemic intuitions? And what sort of epistemological theories do we want? We will take up each of these questions in the following sections. (shrink)

In a letter to Benjamin Rush, Jefferson includes a syllabus—a comparative account of the merits of Jewish morality, ancient philosophy, and the precepts of Jesus. Using the syllabus as a guide, this paper is a critical examination of the influence of ancient ethical and religious thinking on Jefferson’s ethical and religious thinking—viz., Jefferson’s views of the ethics and religion of the Hebrews, the ancient philosophers, and Jesus.

The application of the precautionary principle to an area of environmental protection, such as nature conservation, requires commitment to the idea that full scientific proof of a causal link between a potentially damaging operation and a long term environmental impact is not required. Adoption of the principle in Government statements related to sustainable development should therefore be seen in this context. The paper addresses the particular case of marine fish farming in Scotland where the principle was advocated but not (...) upheld in practice. In the light of this experience there is a need for educators and philosophers, ethicists and concerned scientists to ensure that the principle is more widely interpreted and understood. (shrink)

The paper addresses the use of heterogeneous ensembles of intelligent unmanned vehicles in such a perspective field of innovations as an unmanned fishery. The issues of joint activity of unmanned vehicles of different types in fishing operations based on intelligent technologies are investigated. The “smart fishing” approach based on the joint fishing operation model is proposed. The operational framework that includes missions, roles, and activity scenarios embedded in the discretized spatial model is presented. The scenario activities are considered as the (...) sequences of pentad that determine executing specific functions concerning the specified waypoint, timepoints, and the states of vehicles. The definition of the plan as the scenario prototype that needs adjusting to the conditions of the situational context is proposed. The coordination problem regarding the joint activities of the unmanned vehicles and their scenarios is defined and the coordination framework based on the distributed common board model and coordination primitives is presented. The prototype of the intelligent scenario-based system including the implementation of both operational and coordination frameworks developed for the control of unmanned vehicles is described. This system makes unmanned vehicles capable to absorb all the latest advances in intelligent technologies to perform smart fishing operations jointly in a large heterogeneous group. The proposed approach to smart fishing using intelligent technologies makes it possible to detach fishermen from the fishing activities dangerous to their life and health, to reduce significantly poaching and illegal fishing, to increase the overall efficiency of fishing operations, and even to save the marine ecosystem. (shrink)

Donald T. Campbell argued that the organization of university departments shaped the boundaries among specialties. This article extends his argument in two ways. First, specialties are also shaped by other institutions, such as sponsors and learned societies. Second, the intersection among specialties is shaped by the complexity of the problems that research addresses. Specialization of research is a way to deal with the complexity of nature. One way of doing this is to erect specialties that focus on different aspects of (...) nature, and which do not overlap in subject matter. This view is the basis of Campbell’s “fish-scale” model of relations among specialties, and assumes that nature is descriptively complex in the sense of William C. Wimsatt . But specialties often overlap and are thus interactively complex as well. Here I argue that a kind of interactive complexity—collaborative complexity—arises when research on a problem must take the not-yet-established contents of multiple specialties into account. Such compound problems are exemplified by attempts to explain historical particulars, such as particular adaptations in single species, e.g., masculinization in Spotted Hyenas. (shrink)

Since 9/11, citizens of all nations have been searching for a democratic public philosophy that provides practical and inspiring answers to the problems of the twenty-first century. Drawing on the wisdom of past and present pragmatist thinkers, Judith M. Green maps a contemporary form of citizenship that emphasizes participation and cooperation and reclaims the critical role of social movements and nongovernmental organizations. Starting with empowering processes of storytelling, truth and reconciliation, and collaborative vision-questing that allow individuals to give voice and (...) new meaning to their loss, anxiety, and hope, Green frames cooperative inquiries to guide transformative actions. From this "second strand" of the democratic experience, leaders and participating citizens can help to shape a more desirable democratic future. In dialogue with Richard Rorty, Judith Butler, James Baldwin, Martin Luther King Jr., Elie Wiesel, Viktor Frankl, Cornel West, and other contemporary thinkers, Green defines the need for deeper understanding and fulfillment of the potentials of the democratic ideal. Drawing insights from Thomas Jefferson, Walt Whitman, William James, John Dewey, Jane Adams, and other earlier thinkers, Green frames a pragmatist understanding of emerging realities and possibilities, growing wells of shared truths, multifaceted histories, and mutually transformative experiences of citizenship. Employing examples from America's complex history and from recent world events, Green locates four sites for effective citizen activism: government at all levels, nonprofit organizations, issue-focused campaigns and social movements, and daily urban living. Green shows how citizens can revive social hope and deepen the democratic experience by drawing on their own knowledge and developing their capabilities through inclusive civic participation. (shrink)

Hegel's very first acknowledged publication was, among other things, an attack on Fichte. In 1801, Hegel was still laboring in almost complete obscurity, while Fichte was an international sensation, though already somewhat past the peak of his meteoric career. In the 1801 Differenzschrift, Hegel cut his teeth by criticizing Fichte's already widelycriticised Wissenschaftslehre, and by demonstrating that Schelling's philosophical system was not simply to be equated with it. Fichte himself never bothered to respond to Hegel's criticisms; indeed he never publicly (...) acknowledged their existence. This was not because he was unconcerned with criticisms of his views; quite the contrary. But at the time he had bigger fish to fry. He responded to Jacobi's criticisms, and to Schelling's; he replied in great detail to critical questions raised by Reinhold, and with vituperative intensity to objections raised by skeptics and purportedly loyal Kantians. But Hegel's Differenzschrift was left without a Fichtean rebuttal. This is a pity, both because of the missed opportunity to illuminate by controversy central issues at stake in the post-Kantian period, but also because it made it easier for Hegel simply to reiterate his youthful criticism as if it were the last word. And reiterate it he did: in one form or another Hegel's early criticisms of Fichte reappear at every subsequent stage of his career: in the Phenomenology, in the Science of Logic, in the Encyclopaedia, as the final chapter in Hegel's History of Philosophy, and in countless other minor works and documents from the Nachlass and correspondence. (shrink)

In this paper it is argued that no CSR program can be successful in a development context in general, and in South Africa in particular, unless skills development and therefore empowerment is integrated in every part of the program. The Chinese proverb, “give a man a fish and he will eat for a day; teach him to fish and he will eat for a lifetime,” is the theme of this paper. While it is good to provide people with (...) financial and other means in order to help them, sustainable development cannot be achieved if people are not equipped with the necessary skills to use these means, and thereby empowered to provide for themselves and others in the future. (shrink)

Hegel’s very first acknowledged publication was, among other things, an attack on Fichte.1 In 1801, Hegel was still laboring in almost complete obscurity, while Fichte was an international sensation, though already somewhat past the peak of his meteoric career. In the 1801 Differenzschrift, Hegel cut his teeth by criticizing Fichte’s already widely-criticized Wissenschaftslehre, and by demonstrating that Schelling’s philosophical system was not simply to be equated with it. Fichte himself never bothered to respond to Hegel’s criticisms; indeed he never publicly (...) acknowledged their existence. This was not because he was unconcerned with criticisms of his views; quite the contrary. But at the time he had bigger fish to fry. He responded to Jacobi’s criticisms, and to Schelling’s; he replied in great detail to critical questions raised by Reinhold, and with vituperative intensity to objections raised by skeptics and purportedly loyal Kantians. But Hegel’s Differenzschrift was left without a Fichtean rebuttal. This is a pity, both because of the missed opportunity to illuminate by controversy central issues at stake in the post-Kantian period, but also because it made it easier for Hegel simply to reiterate his youthful criticism as if it were the last word. And reiterate it he did: in one form or another Hegel’s early criticisms of Fichte reappear at every subsequent stage of his career: in the Phenomenology, in the Science of Logic, in the Encyclopaedia, as the final chapter in Hegel’s History of Philosophy, and in countless other minor works and documents from the Nachlass and correspondence. (shrink)

Environmental change requires individuals and institutions to facilitate adaptive governance. However, facilitating adaptive governance may be difficult because resource users' perceptions of desirable ways of life vary. These perceptions influence preferences related to environmental governance and may stem from the ways individuals subjectively value their work and their connections to their environment. This paper uses a value-based approach to examine individual and institutional preferences for adaptive governance in Carelmapu, Chile. We show that two groups had different value frames rooted in (...) divergent ontologies which influenced their actions related to adaptive governance, creating conflict. (shrink)

We study the viability domains of bio-economic constraints for fishing model of hermaphrodite population, displaying three stages, juvenile, female and male. The dynamic of this model is subject to two constraints: an ecological constraint ensuring the stock perennity, and an economic constraint ensuring a minimum revenue for fishermen. Using viability kernel, we find out a viability domain which simultaneously guarantees a minimum stock level and a minimum income for fleets.