Blurb: Thoreau wrote that we have professors of philosophy but no philosophers. Can't we have both? Why doesn't philosophy hold a more central place in our lives? Why should it? Eloquently opposing the analytic thrust of philosophy in academia, noted pluralist philosopher Bruce Wilshire answers these questions and more in an effort to make philosophy more meaningful to our everyday lives. Writing in an accessible style he resurrects classic yet neglected forms of inquiring and communicating. In a series of personal (...) essays, Wilshire describes what is wrong with the current state of philosophy in American higher education, namely the cozy but ultimately suffocating confinements of professionalism. He reclaims the role of the philosopher as one who, like Socrates, would goad us out of self-contentedness into a more authentic way of being and knowing. Table of Contents Preface 1. Nihilistic Consequences of Analytic Philosophy 2. ” The Ph.D. Octopus”: William James's Prophetic Grasp of the Failures of Academic Professionalism 3. The Pluralist Rebellion in the American Philosophical Association 4. Phenomenology in the United States 5. Nature or Nurture?: The Significance of Indigenous Thought 6. Conceptual Problems in Grasping Genocide 7. Henry Bugbee: Philospher of Intimacy 8. William James on the ” Spiritual” 9. Looking for Bek Acknowledgments Index. (shrink)

In this paper we explore material simplicity, defined as the virtue disposing us to act appropriately within the sphere of our consumer decisions. Simplicity is a conscientious and restrained attitude toward material goods that typically includes (1) decreased consumption and (2) a more conscious consumption; hence (3) greater deliberation regarding our consumer decisions; (4) a more focused life in general; and (5) a greater and more nuanced appreciation for other things besides material goods, and also for (6) material goods themselves. (...) It is to be distinguished from simple-mindedness, a return to nature, or poverty. Simplicity overlaps with traditional virtues such as temperance, frugality, and wisdom, and sustains and enables traditional virtues such as justice and generosity. Simplicity is a virtue because it furthers human flourishing, both individual and social, and sustains nature’s ecological flourishing. For analytic purposes, we consider six areas in which simplicity can make important contributions: (1) basic individual flourishing, (2) basic societal flourishing, (3) individual freedom or autonomy, (4) the acquisition of knowledge, (5) living meaningfully, and (6) preserving and protecting nonhuman beings. The proven failure of materialism to secure subjective happiness or objective flourishing argues for the practice of voluntary simplicity and for the radical reform of modern consumer societies. (shrink)

Business ethics is a topic receiving much attention in the literature. However, the term 'business ethics' is not adequately defined. Typical definitions refer to the rightness or wrongness of behavior, but not everyone agrees on what is morally right or wrong, good or bad, ethical or unethical. To complicate the problem, nearly all available definitions exist at highly abstract levels. This article focuses on contemporary definitions of business ethics by business writers and professionals and on possible areas of agreement among (...) the available definitions. Then a definition is synthesized that is broad enough to cover the field of management in a sense as full as most managers might conceive of it. (shrink)

The U.S. and Canadian health care systems are more similar than is commonly believed. This article debunks some of the powerful myths about these health care systems and opens up the discussion for greater policy learning from both sides of the border. Cross-border comparisons can yield a number of lessons from common policy challenges such as cost control, physician organization and payment, and the organization of health coverage and services for Native Americans and Indigenous Canadians.

This paper seeks to show Kant’s importance for the formal distinction between descriptive natural history and a developmental history of nature that entered natural history discussions in the late eighteenth century. It is argued that he developed this distinction initially upon Buffon’s distinctions of ‘abstract’ and ‘physical’ truths, and applied these initially in his distinction of ‘varieties’ from ‘races’ in anthropology. In the 1770s, Kant appears to have given theoretical preference to the ‘history’ of nature [Naturgeschichte] over ‘description’ of nature (...) [Naturbeschreibung]. Following Kant’s confrontations with Johann Herder and Georg Forster in the late 1780s, Kant weakened the epistemic status of the ‘history of nature’ and gave theoretical preference to ‘description of nature’. As a result, Kant’s successors, such as Goethe, could draw from Kant either a justification for a developmental history of nature, or, as this paper argues, a warrant from the critical philosophy for denying the validity of the developmental history of nature as anything more than a ‘regulative’ idea of reason. (shrink)

The doctrines and teachings of the Church of Jesus Christ of Latter-day Saints support and even demand a strong environmental ethic. Such an ethic is grounded in the inherent value of all souls and in God’s commandment of stewardship. Latter-day Saint doctrine declares that all living organisms have souls and explicitly states that the ability of creatures to know some degree of satisfaction and happiness should be honored. God’s own concern for the well-being and progress of all life, and His (...) sacrifice through Jesus Christ, illustrate the generous way that He expects His children to exercise their brief stewardship of this world. In addition, the important role nature has played in the religious lives of Latter-day Saint members, from the Prophet Joseph Smith to the present day, argues strongly for wilderness preservation as a spiritual resource for future generations. (shrink)

This article re-examines the theoretical basis for environmental and heritage interpretation in tourist settings in the light of hermeneutic philosophy. It notes that the pioneering vision of heritage interpretation formulated by Freeman Tilden envisaged a broadly educational, ethically informed and transformative art. By contrast, current cognitive psychological attempts to reduce interpretation to the monological transmission of information, targeting universal but individuated cognitive structures, are found to be wanting. Despite growing signs of diversity, this information processing approach to interpretation remains dominant. (...) The article then presents the alternative paradigm of hermeneutics through the works of Schleiermacher, Dilthey, Heidegger and Gadamer, to provide a broader interpretation of interpretation. This not only captures the essence of Tilden’s definition but construes heritage interpretation as a more inclusive, culturally situated, critically reflexive and dialogical practice. (shrink)

To properly understand behavior, we must obtain both ultimate and proximate explanations. Put briefly, ultimate explanations are concerned with why a behavior exists, and proximate explanations are concerned with how it works. These two types of explanation are complementary and the distinction is critical to evolutionary explanation. We are concerned that they have become conflated in some areas of the evolutionary literature on human behavior. This article brings attention to these issues. We focus on three specific areas: the evolution of (...) cooperation, transmitted culture, and epigenetics. We do this to avoid confusion and wasted effort—dangers that are particularly acute in interdisciplinary research. Throughout this article, we suggest ways in which misunderstanding may be avoided in the future. (shrink)

The first on the topic of environmental virtue ethics, this book seeks to provide the definitive anthology that will both establish the importance of environmental virtue in environmental discourse and advance the current research on environmental virtue in interesting and original ways. The selections in this collection, consisting of ten original and four reprinted essays by leading scholars in the field, discuss the role that virtue and character have traditionally played in environmental discourse, and reflect upon the role that it (...) should play in the future. (shrink)

Social work is a contested tradition, torn between the demands of social governance and autonomy. Today, this struggle is reflected in the division between the dominant, neoliberal agenda of service provision and the resistance offered by various critical perspectives employed by disparate groups of practitioners serving diverse communities. Critical social work challenges oppressive conditions and discourses, in addition to addressing their consequences in individuals’ lives. However, very few recent critical theorists informing critical social work have advocated revolution. A challenging exception (...) can be found in the work of Cornelius Castoriadis (1922–97), whose explication of ontological underdetermination and creation evades the pitfalls of both structural determinism and post-structural relativism, enabling an understanding of society as the contested creation of collective imaginaries in action and a politics of radical transformation. On this basis, we argue that Castoriadis’s radical-democratic revisioning of revolutionary praxis can help in reimagining critical social work’s emancipatory potential. (shrink)

Niche construction refers to the activities of organisms that bring about changes in their environments, many of which are evolutionarily and ecologically consequential. Advocates of niche construction theory (NCT) believe that standard evolutionary theory fails to recognize the full importance of niche construction, and consequently propose a novel view of evolution, in which niche construction and its legacy over time (ecological inheritance) are described as evolutionary processes, equivalent in importance to natural selection. Here, we subject NCT to critical evaluation, in (...) the form of a collaboration between one prominent advocate of NCT, and a team of skeptics. We discuss whether niche construction is an evolutionary process, whether NCT obscures or clarifies how natural selection leads to organismal adaptation, and whether niche construction and natural selection are of equivalent explanatory importance. We also consider whether the literature that promotes NCT overstates the significance of niche construction, whether it is internally coherent, and whether it accurately portrays standard evolutionary theory. Our disagreements reflect a wider dispute within evolutionary theory over whether the neo-Darwinian synthesis is in need of reformulation, as well as different usages of some key terms (e.g., evolutionary process). (shrink)

The term 'fascism' continues to be very much in currency in Philippines society. To the Filipino people, its meaning is often drawn from pained memory of wholesale deprivation of democratic rights and large-scale human rights abuses. Yet, to many, the fear of fascism has still to give way to a deeper understanding of this menace. This may hold true even among those belonging to the progressive movement. One Marxist philosopher and theoretician who gave extended treatment of the issues surrounding the (...) character and conditions giving rise to fascism was Nicos Poulantzas, whose theory is employed here to interrogate the debates about fascism in the post-Marcos Philippines context. (shrink)

The mass movement of people across the globe constitutes a major feature of world politics today. -/- Whatever the cause of the movement - often war, famine, economic hardship, political repression or climate change - the governments of western capitalist states see this 'torrent of people in flight' as a serious threat to their stability and the scale of this migration indicates a need for a radical re-thinking of both political theory and practice, for the sake of political, social and (...) economic justice. -/- This book argues that there is at present a serious gap between the legal and social practices of immigration and naturalisation in liberal democratic states and any theoretical justification for such practices that can be made within the tradition of liberal political philosophy. How can liberal states develop institutions of democratic citizenship and at the same time justifiably exclude 'outsiders' from participating in those institutions? The book examines various responses to this contradiction within the liberal tradition, and finds none of them satisfactory - there are no consistently liberal justifications for immigration control and this has serious implications both for liberal practice and theory. (shrink)

Writing in EIA 22, no. 1, Mathias Risse presented a novel way to think about the problem of immigration in the context of global justice, adopting the standpoint of the common ownership of the earth. The following Exchange is in response to that essay.

Composition as identity, as I understand it, is a theory of the composite structure of reality. The theory’s underlying logic is irreducibly plural; its fundamental primitive is a generalized identity relation that takes either plural or singular arguments. Strong versions of the theory that incorporate a generalized version of the indiscernibility of identicals are incompatible with the framework of plural logic, and should be rejected. Weak versions of the theory that are based on the idea that composition is merely analogous (...) to identity are too weak to be interesting, lacking in metaphysical consequence. I defend a moderate version according to which composition is a kind of identity, and argue that the difference is metaphysically substantial, not merely terminological. I then consider whether the notion of generalized identity, though fundamental, can be elucidated in modal terms by reverse engineering Hume’s Dictum. Unfortunately, for realists about possible worlds, such as myself,... (shrink)

: The transplantation of adult human neural stem cells into prenatal non-humans offers an avenue for studying human neural cell development without direct use of human embryos. However, such experiments raise significant ethical concerns about mixing human and nonhuman materials in ways that could result in the development of human-nonhuman chimeras. This paper examines four arguments against such research, the moral taboo, species integrity, "unnaturalness," and human dignity arguments, and finds the last plausible. It argues that the transfer of human (...) brain or retinal stem cells to nonhuman embryos would not result in the development of human-nonhuman chimeras that denigrate human dignity, provided such stem cells are dissociated. The article provides guidelines that set ethical boundaries for conducting such research that are consonant with the requirements of human dignity. (shrink)

The first on the topic of environmental virtue ethics, this book seeks to provide the definitive anthology that will both establish the importance of environmental virtue in environmental discourse and advance the current research on environmental virtue in interesting and original ways. The selections in this collection, consisting of ten original and four reprinted essays by leading scholars in the field, discuss the role that virtue and character have traditionally played in environmental discourse, and reflect upon the role that it (...) should play in the future. (shrink)

The question of education for democratic ‘empowerment and liberation’, and how this might guide pedagogic practice is seldom raised and extremely challenging for social work education today. This chapter takes up the proposition that social work, through its educational practices, ‘can’ deliver on its promise of ‘democratic practice’ if democracy is understood as a process and not a predefined product. We argue that such a process and its embodiment in institutions cannot exist without the formation of radically democratic subjects, people (...) (including social workers) capable of questioning dominant social forms and of creating new forms and practices. Accordingly, this chapter explores the educational implications for social work of the work of the revolutionary theorist, Cornelius Castoriadis (1921–1997). Castoriadis’ philosophy accords a crucial role to democratic pedagogy (paideía) as an essential form of praxis in the creation of a radically democratic, egalitarian and sustainable society. In particular, we examine his idea (against (neo)liberal individualisation) that ‘autonomy’ is simultaneously an individual and social project that begins in, and is always dependent upon, individual and collective self-reflection. This argument is illustrated by examples from the authors’ classroom experiences of teaching both critical reflection and critical social theory to social work students in Australian universities, on the premise that both are indispensable in social work education as a democratic practice for ‘empowerment and liberation’. The chapter outlines a brief discussion of Castoriadis, his main ideas and the pedagogic dimensions of his philosophy before bringing the latter to bear on the authors’ teaching experiences. (shrink)

It follows from Humean principles of plenitude, I argue, that island universes are possible: physical reality might have 'absolutely isolated' parts. This makes trouble for Lewis's modal realism; but the realist has a way out. First, accept absolute actuality, which is defensible, I argue, on independent grounds. Second, revise the standard analysis of modality: modal operators are 'plural', not 'individual', quantifiers over possible worlds. This solves the problem of island universes and confers three additional benefits: an 'unqualified' principle of compossibility (...) can be accepted; the possibility of nothing can be accommodated; and the identity of indiscernible worlds can be decisively refuted. (shrink)

This volume contains eighteen papers, three with new postscripts, that were written over the past 35 years. Five of the papers have not been previously published. Together they provide a comprehensive account of modal reality—the realm of possible worlds—from a Humean perspective, with excursions into neighboring topics in metaphysics. Part 1 sketches an account of reality as a whole, both the mathematical and the modal, defending a form of plenitudinous realism: every consistent proposition is true of some portion of reality. (...) Part 2 presents and defends a realist theory of concrete possible worlds with an absolute ontological distinction between the actual and the merely possible. Part 3 presents and defends a Humean account of modal plenitude, formulating and endorsing principles of recombination, of plenitude of possible structures, and of plenitude of alien contents. Part 4 applies the Humean account to truthmaking, mereology, spacetime, and quantities. I argue that holding fast to Humean strictures leads to views that differ in radical ways from those put forth by contemporary metaphysicians. (shrink)

This paper is a critical study of Kant’s antinomy of saving faith. In the first section, I sketch aspects of Kant’s philosophical account of sin and atonement that help explain why he finds saving faith problematic from the moral point of view. I proceed in the next section to give a detailed exposition of Kant’s remarkable antinomy and of his proposal for resolving it theoretically. In the third and final section, I argue that alternative ways of resolving the antimony both (...) respond to the deepest of Kant’s moral concerns and comport better with the traditional Christian conviction that saving faith can have for its object the historical individual Jesus Christ. (shrink)

In this chapter, I survey what I call Lewisian approaches to modality: approaches that analyze modality in terms of concrete possible worlds and their parts. I take the following four theses to be characteristic of Lewisian approaches to modality. (1) There is no primitive modality. (2) There exists a plurality of concrete possible worlds. (3) Actuality is an indexical concept. (4) Modality de re is to be analyzed in terms of counterparts, not transworld identity. After an introductory section in which (...) I motivate analyzing modality in terms of possible worlds, I devote one section to each of these four theses. For each thesis, I take Lewis’s interpretation and defense as my starting point. I then consider and endorse alternative ways of accepting the thesis, some of which disagree substantially with Lewis’s interpretation or defense. There is more than one way to be a Lewisian about modality. (shrink)

Phillip Cary argues that Augustine invented or created the concept of self as an inner space--as space into which one can enter and in which one can find God. This concept of inwardness, says Cary, has worked its way deeply into the intellectual heritage of the West and many Western individuals have experienced themselves as inner selves. After surveying the idea of inwardness in Augustine's predecessors, Cary offers a re-examination of Augustine's own writings, making the controversial point that in (...) his early writings Augustine appears to hold that the human soul is quite literally divine. Cary goes on to contend that the crucial Book 7 of the Confessions is not a historical report of Augustine's "conversion" experience, but rather an explanation of his intellectual development over time. (shrink)

In this paper, I critique two conceptions of mechanisms, namely those put forth by Stuart Glennan (Erkenntnis 44:49–71, 1996; Philosophy of Science 69:S342–S353, 2002) and Machamer et al. (Philosophy of Science 67:1–25, 2000). Glennan’s conception, I argue, cannot account for mechanisms involving negative causation because of its interactionist posture. MDC’s view encounters the same problem due to its reificatory conception of activities—this conception, I argue, entails an onerous commitment to ontological dualism. In the place of Glennan and MDC, I propose (...) a “modified conception” of mechanisms, which (a) obviates the problem of negative causation by reinterpreting MDC’s activities according to a “descriptivist” account, and (b) avoids MDC’s problem by postulating a monistic ontology of entities. Thus, by solving these problems, my modified conception offers a cogent, more adequate alternative to Glennan’s and MDC’s conceptions of mechanisms. (shrink)

According to David Lewis, a realist about possible worlds must hold that actuality is relative: the worlds are ontologically all on a par; the actual and the merely possible differ, not absolutely, but in how they relate to us. Call this 'Lewisian realism'. The alternative, 'Leibnizian realism', holds that actuality is an absolute property that marks a distinction in ontological status. Lewis presents two arguments against Leibnizian realism. First, he argues that the Leibnizian realist cannot account for the contingency of (...) actuality. Second, he argues that the Leibnizian realist cannot explain why skepticism about one's own actuality is absurd. In this paper, I mount a defense of Leibnizian realism. (shrink)

I argue for an environmental virtue ethics which specifies human excellence and flourishing in relation to nature. I consider Henry David Thoreau, Aldo Leopold, and Rachel Carson as environmental virtue ethicists, and show that these writers share certain ethical positions that any environmental virtue ethics worthy of the name must embrace. These positions include putting economic life in its proper,subordinate place within human life as a whole; cultivating scientific knowledge, while appreciating its limits; extending moral considerability to the nonhuman world; (...) and supporting wilderness protection. I argue that Thoreau, Leopold, and Carson themselves exemplify the potential for cultivating excellence in engagement with wild nature: their lives are among our most powerful arguments for its preservation. (shrink)

I am a realist of a metaphysical stripe. I believe in an immense realm of "modal" and "abstract" entities, of entities that are neither part of, nor stand in any causal relation to, the actual, concrete world. For starters: I believe in possible worlds and individuals; in propositions, properties, and relations (both abundantly and sparsely conceived); in mathematical objects and structures; and in sets (or classes) of whatever I believe in. Call these sorts of entity, and the reality they comprise, (...) metaphysical. In contrast, call the actual, concrete entities, and the reality they comprise, physical. Physical and metaphysical reality together comprise all that there is. In this paper, it is not my aim to defend realism about any particular metaphysical sort of entity. Rather, I ask quite generally whether and how any brand of realism about metaphysical sorts of entity could be justified? (shrink)

Was Plato a Pythagorean? Plato's students and earliest critics thought so, but scholars since the nineteenth century have been more skeptical. With this probing study, Phillip Sidney Horky argues that a specific type of Pythagorean philosophy, called "mathematical" Pythagoreanism, exercised a decisive influence on fundamental aspects of Plato's philosophy. The progenitor of mathematical Pythagoreanism was the infamous Pythagorean heretic and political revolutionary Hippasus of Metapontum, a student of Pythagoras who is credited with experiments in harmonics that led to innovations (...) in mathematics. The innovations of Hippasus and other mathematical Pythagoreans, including Empedocles of Agrigentum, Epicharmus of Syracuse, Philolaus of Croton, and Archytas of Tarentum, presented philosophers like Plato with novel ways to reconcile empirical knowledge with abstract mathematical theories. Plato and Pythagoreanism demonstrates how mathematical Pythagoreanism established many of the fundamental philosophical questions Plato dealt with in his central dialogues, including Cratylus, Phaedo, Republic, Timaeus, and Philebus. In the process, it also illuminates the historical significance of the mathematical Pythagoreans, a group whose influence on the development of philosophical and scientific methods has been obscured since late antiquity. The picture that results is one in which Plato inherits mathematical Pythagorean method only to transform it into a powerful philosophical argument about the essential relationships between the cosmos and the human being. (shrink)

The article explicates a notion of prudence according to which an agent acts prudently if he acts so as to satisfy not only his present preferences, but his past and future preferences as well. A simplified decision-theoretic framework is developed within which three analyses of prudence are presented and compared. That analysis is defended which can best handle cases in which an agent's present act will affect his future preferences.

This paper identifies three claims that feature prominently in recent discussions concerning the experience of silence: that experiences of silence are the most “negative” of perceptions, that we do not hear silences because those silences cause our experiences of silence, and that to hear silence is to hear a temporal region devoid of sound. The principal proponents of this approach are Phillips and Soteriou, and here I present a series of objections to common elements of their attempts to place these (...) three claims within an account of experience of silence. The final section of the paper returns to the first of the three claims and argues that, in fact, there is no good reason to accept it as initially formulated. However, when properly formulated, the claim ceases to offer support for Phillips’s and Soteriou’s approach to experience of silence. (shrink)

In the recent literature on the nature of sound, there is an emerging consensus rejection of what might be thought of as the scientifically informed commonsense position: that sounds, whatever else they may be, must be entities that mediate between the source of the sound and the subject hearing it. This paper offers an argument for such "medial" theories of sound. This argument is intended to shift attention from the two considerations that have dominated the debate thus far: the relevant (...) scientific facts about audition and the spatial phenomenology of auditory experience. (shrink)

If realism about possible worlds is to succeed in eliminating primitive modality, it must provide an 'analysis' of possible world: nonmodal criteria for demarcating one world from another. This David Lewis has done. Lewis holds, roughly, that worlds are maximal unified regions of logical space. So far, so good. But what Lewis means by 'unification' is too narrow, I think, in two different ways. First, for Lewis, all worlds are (almost) 'globally' unified: at any world, (almost) every part is directly (...) linked to (almost) every other part. I hold instead that some worlds are 'locally' unified: at some worlds, parts are directly linked only to "neighboring" parts. Second, for Lewis, each world is (analogically) 'spatio-temporally' unified; every world is 'spatio-temporally' isolated from every other. I hold instead: a world may be unified by nonspatio-temporal relations; every world is 'absolutely' isolated from every other. If I am right, Lewis's conception of logical space is impoverished: perfectly respectable worlds are missing. (shrink)

Darwin's art collection : the prints, drawings, and photographs Darwin collected in the 1860s and 70s -- Illustrations and illusion : strategies Darwin used in illustrating his books -- Art, experience, and observation : Darwin's knowledge of art history and use of illustration in his books -- Darwin and the passions : how passion manuals informed Darwin's research -- Photography and evolution meet : connections between photography and biology in the 1860s -- Method to their madness : how photography in (...) mental hospitals influenced Darwin -- Laughing and crying : Darwin's quest for pictures of expressive babies -- Darwin's eyes and ears : the artists who guided Darwin's search for pictures -- Darwin's art photographer : Oscar Rejlander, Darwin's favorite photographer -- Rejlander's performances : posing for Darwin's pictures -- Alice, eugenics, and the spirit world : the aftermath of Darwin's experiments. (shrink)

In this paper I argue that holes are not objects, but should instead be construed as properties or relations. The argument proceeds by first establishing a claim about angles: that angles are not objects, but properties or relations. It is then argued that holes and angles belong to the same category, on the grounds that they share distinctive existence and identity conditions. This provides an argument in favour of categorizing holes as one categorizes angles. I then argue that a commitment (...) to the existence of properties to be identified with holes provides sufficient resources to account for true claims about holes. (shrink)

According to the Intergovernmental Panel on Climate Change, human population growth is one of the two primary causes of increased greenhouse gas emissions and accelerating global climate change. Slowing or ending population growth could be a cost effective, environmentally advantageous means to mitigate climate change, providing important benefits to both human and natural communities. Yet population policy has attracted relatively little attention from ethicists, policy analysts, or policy makers dealing with this issue. In part, this is because addressing population matters (...) means wading into a host of contentious ethical issues, including family planning, abortion, and immigration. This article reviews the scientific literature regarding voluntary population control's potential contribution to climate change mitigation. It considers possible reasons for the failure of climate ethicists, analysts, and policy makers to adequately assess that contribution or implement policies that take advantage of it, with particular reference to the resistance to accepting limits to growth. It explores some of the ethical issues at stake, considering arguments for and against noncoercive population control and asking whether coercive population policies are ever morally justified. It also argues that three consensus positions in the climate ethics literature regarding acceptable levels of risk, unacceptable harms, and a putative right to economic development, necessarily imply support for voluntary population control. (shrink)

Which mathematical structures are possible, that is, instantiated by the concrete inhabitants of some possible world? Are there worlds with four-dimensional space? With infinite-dimensional space? Whence comes our knowledge of the possibility of structures? In this paper, I develop and defend a principle of plenitude according to which any mathematically natural generalization of possible structure is itself possible. I motivate the principle pragmatically by way of the role that logical possibility plays in our inquiry into the world.