Many philosophers believe that a deflationist theory of truth must conservatively extend any base theory to which it is added. But when applied to arithmetic, it's argued, the imposition of a conservativeness requirement leads to a serious objection to deflationism: for the Gödel sentence for Peano Arithmetic is not a theorem of PA, but becomes one when PA is extended by adding plausible principles governing truth. This paper argues that no such objection succeeds. The issue turns on how we (...) understand the notion of logical consequence implicit in any conservativeness requirement, and whether we possess a categorical conception of the natural numbers. I offer a disjunctive response: if we possess a categorical conception of arithmetic, then deflationists have principled reason to accept a rich notion of logical consequence according to which the Gödel sentence follows from PA. But if we do not, then the reasons for requiring the derivation of the Gödel sentence lapse, and deflationists are free to accept a conservativeness requirement stated proof-theoretically. Either way, deflationism is in the clear. (shrink)

Truth is often considered to be a logico-linguistic tool for expressing indirect endorsements and infinite conjunctions. In this article, I will point out another logico-linguistic function of truth: to enable and validate what I call a blind argument, namely, an argument that involves indirectly endorsed statements. Admitting this function among the logico-linguistic functions of truth has some interesting consequences. In particular, it yields a new type of so-called conservativeness argument, which poses a new type of threat to deflationism about (...) truth. (shrink)

My contribution to the symposium on Goedel’s philosophy of mathematics at the spring 2006 Association for Symbolic Logic meeting in Montreal. Provisional version: references remain to be added. To appear in an ASL volume of proceedings of the Goedel sessions at that meeting.

We formulate a Π1 sentence τ which is a version of the Tableau consistency of GlΔ0. The sentence τ is true and is provable in GlΔ0 + exp. We construct a model M of GlΔ0+Ω1+τ+BGs1 which has no proper end-extension to a model of GlΔ0+Ω1+τ. Also we prove that GlΔ0+Ω1+τ is not Π1 conservative over GlΔ0+τ.

This introduction to biological conservation assesses the value judgments at the heart of conservation. The author elaborates on such questions as: how much habitat does an endangered species require?; does this particular species deserve to be saved?; who will pay for its upkeep?; and much more.

A conservation principles tell us that some quantity, quality, or aspect remains constant through change. Such principles appear already in ancient and medieval natural philosophy. In one important strand of Greek cosmology, the rotatory motion of the celestial orbs is eternal and immutable. In optics, from at least the time of Euclid, the angle of reflection is equal to the angle of incidence when a ray of light is reflected. According to some versions of the medieval impetus theory of motion, (...) impetus remains in a projected body (and the associated motion persists) permanently unless the body is subject to outside interference. These examples could be multiplied. But it was in the seventeenth century that conservation principles began to play an absolutely central role in scientific theories. Each of Galileo Galilei, René Descartes, Christiaan Huygens, Gottfried Leibniz, and Isaac Newton founded his approach to physics upon the principle of inertia—that unless interfered with a body will undergo uniform rectilinear motion. A multitude of other conservation principles gained currency during the seventeenth century—some still with us, some long ago left behind. Descartes provides an interesting example of an author who attempted to derive all of his physical principles from conservation laws (Principles of Philosophy, see especially articles 36 to 42 of Part II). Descartes believed that the principles of his physics could be derived from the immutability of God, supplemented only by very weak assumptions about the existence of change in the world. He claims, in fact, that we ought to postulate the strongest conservation laws consistent with such change. These include. (shrink)

We discuss two desirable properties of deflationary truth theories: conservativeness and maximality. Joining them together, we obtain a notion of a maximal conservative truth theory - a theory which is conservative over its base, but can't be enlarged any further without losing its conservative character. There are indeed such theories; we show however that none of them is axiomatizable, and moreover, that there will be in fact continuum many theories of this sort. It turns out in effect that the (...) deflationist still needs some additional principles, which would permit him to construct his preferred theory of truth. (shrink)

_Conservative Reductionism_ sets out a new theory of the relationship between physics and the special sciences within the framework of functionalism. It argues that it is wrong-headed to conceive an opposition between functional and physical properties and to build an anti-reductionist argument on multiple realization. By contrast, all properties that there are in the world, including the physical ones, are functional properties in the sense of being causal properties, and all true descriptions that the special sciences propose can in principle (...) be reduced to physical descriptions by means of functional reduction, despite multiple realization. The book develops arguments for from the metaphysics of properties and the philosophy of physics. These arguments lead to a conservative ontological reductionism. It then develops functional reduction into a fully-fledged, conservative theory reduction by means of introducing functional sub-types that are coextensive with physical types, illustrating that conservative reductionism by means of case studies from biology. (shrink)

Parents can benefit their offspring by conserving resources that the offspring stand to inherit. Thus, inheritance of resources should promote the evolution of propensities to conserve. But inheritance also has another, less obvious effect: it can reduce the fertility of the conserver’s grandchildren, thus reducing the expected number of great-grandchildren. Consequently, inheritance of resources promotes the evolution of conservation less than might be supposed.

A conservation law in physics can be either a constraint on the kinds of interaction there could be or a coincidence of the kinds of interactions there actually are. This is an important, unjustly neglected distinction. Only if a conservation law constrains the possible kinds of interaction can a derivation from it constitute a scientific explanation despite failing to describe the causal/mechanical details behind the result derived. This conception of the relation between “bottom-up” scientific explanations and one kind of “top-down” (...) scientific explanation is motivated by several examples from classical and modern physics. (shrink)

Conservativeness has been proposed as an important requirement for deflationary truth theories. This in turn gave rise to the so-called ‘conservativeness argument’ against deflationism: a theory of truth which is conservative over its base theory S cannot be adequate, because it cannot prove that all theorems of S are true. In this paper we show that the problems confronting the deflationist are in fact more basic: even the observation that logic is true is beyond his reach. This seems (...) to conflict with the deflationary characterization of the role of the truth predicate in proving generalizations. However, in the final section we propose a way out for the deflationist — a solution that permits him to accept a strong theory, having important truth-theoretical generalizations as its theorems. (shrink)

Effective altruism is a growing humanitarian movement with a track record of success in evaluating the effectiveness of charitable spending across a wide range of projects. We suggest ways in which the foundations of this movement can be applied to the complex world of conservation.

We develop a conceptual framework that connects biological heredity and organization. We refer to heredity as the cross-generation conservation of functional elements, defined as constraints subject to organizational closure. While hereditary objects are functional constituents of biological systems, any other entity that is stable across generations—and possibly involved in the recurrence of phenotypes—belongs to their environment. The central outcome of the organizational perspective consists in extending the scope of heredity beyond the genetic domain without merging it with the broad category (...) of cross-generation stability. After discussing some implications, we conclude with a reflection on the relationship between stability and variation. 1Introduction2From Extended Heredity to Cross-generation Stability 2.1Extending the scope of heredity: A brief state of the art2.2Rethinking heredity: Conceptual challenges3Biological Heredity in Light of Organization 3.1Biological organization within organisms and beyond3.2Extending organization in time3.3What is biological heredity?4Implications and Objections 4.1Heredity as a specific kind of cross-generation stability4.2Heredity at various levels of description4.3Non-functional and dysfunctional objects5Conclusions: From Conservation to Variation. (shrink)

Deflationists argue that ‘true’ is merely a logico-linguistic device for expressing blind ascriptions and infinite generalisations. For this reason, some authors have argued that deflationary truth must be conservative, i.e. that a deflationary theory of truth for a theory S must not entail sentences in S’s language that are not already entailed by S. However, it has been forcefully argued that any adequate theory of truth for S must be non-conservative and that, for this reason, truth cannot be deflationary :493–521, (...) 1998; Ketland in Mind 108:69–94, 1999). We consider two defences of conservative deflationism, respectively proposed by Waxman :429–463, 2017) and Tennant :551–582, 2002), and argue that they are both unsuccessful. In Waxman’s hands, deflationists are committed either to a non-purely expressive notion of truth, or to a conception of mathematics that does not allow them to justifiably exclude non-conservative theories of truth. Tennant’s conservative deflationism fares no better: if deflationist truth must be conservative over arithmetic, it can be shown to collapse into a non-conservative variety of deflationism. (shrink)

: "Conservative" bioethics is informed by a rich view of human personhood, a decent respect for the well-considered views of people across the political spectrum, and a philosophy of the state carefully calibrated to ensure that imperfect people can live together in community. The deepest disagreements between conservatives and liberals are rooted in different ways of understanding the moral ideal of equality.

This paper shows how to conservatively extend classical logic with a transparent truth predicate, in the face of the paradoxes that arise as a consequence. All classical inferences are preserved, and indeed extended to the full (truth—involving) vocabulary. However, not all classical metainferences are preserved; in particular, the resulting logical system is nontransitive. Some limits on this nontransitivity are adumbrated, and two proof systems are presented and shown to be sound and complete. (One proof system allows for Cut—elimination, but the (...) other does not.). (shrink)

Conservation biology emerged as an organized academic discipline in the United States in the 1980s though much of its theoretical framework was originally developed in Australia. Significant differences of approach in the two traditions were resolved in the late 1990s through the formulation of a consensus framework for the design and adaptive management of conservation area networks. This entry presents an outline of that framework along with a critical analysis of conceptual issues concerning the four theoretical problems that emerge from (...) it: (i) place prioritization for conservation action; (ii) the selection of surrogates for biodiversity in conservation planning; (iii) the assessment of vulnerability of conservation areas; and (iv) the synchronization of incommensurable criteria including socio-economic constraints on conservation planning. (shrink)

Religious conservatives in the U.S. have frequently opposed public-health measures designed to combat STDs among minors, such as sex education, condom distribution, and HPV vaccination. Using Rawls’s method of conjecture, I will clear up what I take to be a misunderstanding on the part of religious conservatives: even if we grant their premises regarding the nature and source of sexual norms, the wide-ranging authority of parents to enforce these norms against their minor children, and the potential sexual-disinhibition effects of the (...) above public-health measures, their opposition to at least one of these measures, HPV vaccination, cannot be justified. In fact, their comprehensive doctrines, when properly interpreted, should lead them to back this measure and thereby draw closer to a policy consensus with other citizens regarding teenage sexual health. (shrink)

This paper discusses two conservative ways of treating evidence. (I) Closing inquiry involves discounting evidence bearing on one's belief unless it is particularly strong evidence; (II) biased assimilation involves dedicating more investigative resources to scrutinizing disconfirming evidence (than confirming evidence), thereby increasing the chances of finding reasons to dismiss it. It is natural to worry that these practices lead to irrational biases in favor of one's existing beliefs, and that they make one's epistemic condition significantly path-sensitive by giving a bigger (...) role to batches of evidence obtained earlier in the course of inquiry compared with those subsequently acquired. However, I argue that both practices are demanded by considerations of practical rationality. I also argue that, contrary to initial appearances, there is little reason to worry about the effects of these practices on the dynamics of one's beliefs. (shrink)

The conservative, mainly Anglo-Saxon, critique of “social engineering” in Enlightenment thinking, which goes back to Edmund Burke and David Hume, among others, has recently resurfaced in the works of Michael Oakeshott, Roger Scruton, and Friedrich Hayek. This article focuses on their conservative critiques and more specifically on two common issues: the unintended negative consequences of political planning, and the institutions in civil society that act as a positive counterpart to this form of engineering.

The practice of conservation assumes that current persons have some obligations to future generations, but these obligations are complicated by a number of philosophical problems, chief among which is what Derek Parfit calls the Non-Identity Problem. Because our actions now will affect the identities of persons to be born in the distant future, we cannot say that those actions either benefit or harm those persons. Thus, a causal link between our acts and their consequences for particular persons is severed, and (...) the justification for conservation duties toward future generations undermined. I argue for an alternative justification for conservation in the capacity of foresight, which requires us to act not only upon duties that we have now, but also upon those that we will predictably have in the future. In this way, the future generations problem, at least as applied to conservation issues, is overcome. (shrink)

An algebraic block-diagonalization of the Dirac Hamiltonian in a time-independent external field reveals a charge-index conservation law which forbids the physical phenomena of the Klein paradox type and guarantees a single-particle nature of the Dirac equation in strong external fields. Simultaneously, the method defines simpler quantum-mechanical objects—paulions and antipaulions, whose 2-component wave functions determine the Dirac electron states through exact operator relations. Based on algebraic symmetry, the presented theory leads to a new understanding of the Dirac equation physics, including new (...) insight into the Dirac measurements and a consistent scheme of relativistic quantum mechanics of electron in the paulion representation. Along with analysis of the mathematical anatomy of the Klein paradox falsity, a complete set of paradox-free eigenfunctions for the Klein problem is obtained and investigated via stationary solutions of the Pauli-like equations with respective paulion Hamiltonians. It is shown that the physically correct Dirac states in the Klein zone are characterized by the total particle reflection from the potential step and satisfy the fundamental charge-index conservation law. (shrink)

We systematically study conservation theorems on theories of semi-classical arithmetic, which lie in-between classical arithmetic $\mathsf {PA}$ and intuitionistic arithmetic $\mathsf {HA}$. Using a generalized negative translation, we first provide a structured proof of the fact that $\mathsf {PA}$ is $\Pi _{k+2}$ -conservative over $\mathsf {HA} + {\Sigma _k}\text {-}\mathrm {LEM}$ where ${\Sigma _k}\text {-}\mathrm {LEM}$ is the axiom scheme of the law-of-excluded-middle restricted to formulas in $\Sigma _k$. In addition, we show that this conservation theorem is optimal in the (...) sense that for any semi-classical arithmetic T, if $\mathsf {PA}$ is $\Pi _{k+2}$ -conservative over T, then ${T}$ proves ${\Sigma _k}\text {-}\mathrm {LEM}$. In the same manner, we also characterize conservation theorems for other well-studied classes of formulas by fragments of classical axioms or rules. This reveals the entire structure of conservation theorems with respect to the arithmetical hierarchy of classical principles. (shrink)

On estime souvent que les Grecs avaient des phénomènes économiques une approche triviale et non scientifique. Ce point de vue est en partie motivé par ce que l’économiste et historien de la pensée économique J.A. Schumpeter et l’historien de la Grèce antique M.I. Finley considèrent être l’excessive préoccupation des penseurs grecs pour les « vaines » considérations domestiques de nature matérielle, au détriment de l’analyse scientifique des phénomènes économiques. Contre une telle interprétation, l’hypothèse présentée ici est que cette préoccupation répond (...) au souci de la conservation des biens qui, avec leur acquisition et leur bon usage, est l’une des trois activités principales de l’art économique ou oikonomique. L’examen détaillé des deux opérations de conservation que sont le rangement et la gestion, en lien avec les divers aspects du Bien économique qui leur sont associés, permet de le montrer. (shrink)

Conservatives commonly claim that systems of formal education are biased against conservative ideology. I argue that this claim is incorrect, but not because there is no bias against conservatives in formal education. A wide swath of psychological evidence linking personality and ideology indicates that conservatives and liberals differ in their learning orientations, that is, in the values, motivations, and beliefs they bring to learning tasks. These differences in operative epistemologies explain many demographic phenomena relating educational achievement and political ideology. Systems (...) of formal education thus disadvantage conservatives, especially in the later stages of formal education. Conservatives are therefore ‘selected against’ in the process of formal education, not due to their values or ideology but because their learning orientations are not especially conducive to academic success beyond a certain point. However, because the bias against conservatives in not ideological in origin, a case cannot be made that conservatives are victims of institutional injustice. This bias against conservatives in formal education could be mitigated were the purposes of formal education radically modified (the education of the military class in Plato’s Republic serves as a model). But such a model of formal education would ill serve the needs of modern, industrialized, information-driven societies. (shrink)

Philosophers have paid little attention to the distinction between conservation and preservation, apparently because they have accepted John Passmore’s suggestion that conservationism is an expression of anthropocentric motives and that “true” preservationism is an expression of nonanthropocentric motives. Philosophers have therefore concentrated their efforts on this distinction in motives. This reduction,however, is insensitive to important nuances of environmentalist objectives: there are a wide variety of human reasons for preserving natural ecosystems and wild species. Preservationist policies represent a concem to protect (...) biological diversity from the simplifying effects of human management and are motivated by the full range of values (consumptive, aesthetic, scientific, and moral) attached to a diverse biota.Conservationists and preservationists differ mainly in their emphasis on resilience measures versus predictability measures of stability, respectively. The distinction between anthropocentric and nonanthropocentric motives loses importance as emphasis is placed on the longest term values humans place on the proteetion of biological diversity. (shrink)

Few disputes in the annals of US environmentalism enjoy the pedigree of the conservation-preservation debate. Yet, although many scholars have written extensively on the meaning and history of conservation and preservation in American environmental thought and practice, the resonance of these concepts outside the academic literature has not been sufficiently examined. Given the significance of the ideals of conservation and preservation in the justification of environmental policy and management, however, we believe that a more detailed analysis of the real-world use (...) and understanding of these ideas is needed. In this paper, we describe the results of a qualitative, semantic study of the concepts of conservation and preservation undertaken in the context of the Chattahoochee National Forest (CNF), located in northern Georgia (USA). Thirty in-depth interviews were conducted with scientists and north Georgia residents either interested or involved in the future management of the forest. Respondents were asked to define conservation and preservation in their own words and to indicate which approach they felt was more appropriate for the management of the CNF. Qualitative content analysis was used to elicit a set of recurring themes for each foundational concept. Taken together, these themes help to flesh out the meaning of conservation and preservation for citizens and scientists today, and illustrate the evolving nature of two of the more significant and venerable ideas animating US environmental policy and management. (shrink)

Many approaches to the semantics of generic sentences posit an unpronounced quantifier gen. However, while overt quantifiers are conservative, gen does not seem to be. A quantifier Q is conservative iff instances of the following schemas are equivalent: Q As are F and Q As are As that are F. All ravens are black is obviously equivalent to All ravens are ravens that are black, yet ravens are black is not equivalent to ravens are ravens that are black. This may (...) cast doubt on theviability of quantificational analyses of generics. This paper proposes a theory of why such “conservativity” generics are problematic that is compatible with the conservativity of gen and also accounts for perennially troublesome examples such as books are paperbacks and bees are workers. (shrink)

The Exclusion Argument for physicalism maintains that since (1) every physical effect has a sufficient physical cause, and (2) cases of causal overdetermination are rare, it follows that if (3) mental events cause physical events as frequently as they seem to, then (4) mental events must be physical in nature. In defence of (1), it is sometimes said that (1) is supported if not entailed by conservation laws. Against this, I argue that conservation laws do not lend sufficient support to (...) (1) to render its denial ‘unscientific’, and that those who accept (3) and deny (4) may consequently respond to the Exclusion Argument by denying (1) without thereby setting themselves at odds with current science. I also argue that conservation laws are compatible with (3) and the negation of (4), and that one can therefore accept conservation laws and (3) while denying both (1) and (4). (shrink)

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)

Conservation scientists are arguing whether naturalness provides a reasonable imperative for conservation. To clarify this debate and the interpretation of the term natural, I analyze three management strategies – ecosystem preservation, ecosystem restoration, and ecosystem engineering – with respect to the naturalness of their outcomes. This analysis consists in two parts. First, the ambiguous term natural is defined in a variety of ways, including (1) naturalness as that which is part of nature, (2) naturalness as a contrast to artifactuality, (3) (...) naturalness as an historical independence from human actions, and (4) naturalness as possession of certain properties. After that, I analyze the different conceptions with respect to their implications for the three management strategies. The main conclusion is that there exists no single conception of naturalness that could distinguish between the outcomes of the three management methods. Therefore, as long as the outcomes of the different methods are regarded as being of a different value in conservation, we should either abandon the idea of naturalness as the guiding concept in conservation or use the term natural only in the ways that take both its historical and feature dependent meanings into consideration. (shrink)

Tracing the historical roots of modern conservation thought & practice, this book explores current perspectives from evolutionary & community ecology, conservation biology, anthropology, political ecology, economics, and policy.

Conservativity in generalized quantifiers is linked to presupposition filtering, under a propositions-as-types analysis extended with dependent quantifiers. That analysis is underpinned by modeltheoretically interpretable proofs which inhabit propositions they prove, thereby providing objects for quantification and hooks for anaphora.

An eloquent introduction to the ethical and philosophical values at stake in biological conservation, this book familiarizes readers with the general issues and possible solutions to the problems societies face in simultaneously conserving nature and promoting culture.

Misconceptions about energy conservation abound due to the gap between physics and secondary school chemistry. This paper surveys this difference and its relevance to the 1690s–2010s Leibnizian argument that mind-body interaction is impossible due to conservation laws. Justifications for energy conservation are partly empirical, such as Joule’s paddle wheel experiment, and partly theoretical, such as Lagrange’s statement in 1811 that energy is conserved if the potential energy does not depend on time. In 1918 Noether generalized results like Lagrange’s and proved (...) a converse: symmetries imply conservation laws and vice versa. Conservation holds if and only if nature is uniform. The rise of field physics during the 1860s–1920s implied that energy is located in particular places and conservation is primordially local: energy cannot disappear in Cambridge and reappear in Lincoln instantaneously or later; neither can it simply disappear in Cambridge or simply appear in Lincoln. A global conservation law can be inferred in some circumstances. Einstein’s General Relativity, which stimulated Noether’s work, is another source of difficulty for conservation laws. As is too rarely realized, the theory admits conserved quantities due to symmetries of the Lagrangian, like other theories. Indeed General Relativity has more symmetries and hence more conserved energies. An argument akin to Leibniz’s finally gets some force. While the mathematics is too advanced for secondary school, the ideas that conservation is tied to uniformities of nature and that energy is in particular places, are accessible. Improved science teaching would serve the truth and enhance the social credibility of science. (shrink)

In this essay, I examine the controversy concerning the advocacy of ethical values in conservation biology. First, I argue, as others have, that conservation biology is a science laden with values both ethical and non-ethical. Second, after clarifying the notion of advocacy at work, I contend that conservation biologists should advocate the preservation of biological diversity. Third, I explore what ethical grounds should be used for advocating the preservation of ecological systems by conservation biologists. I argue that conservation biologists should (...) defend their preservationist positions on instrumentalist grounds alone if the context of discussion and debate is a scientific one. (shrink)

Scientists in anthropology, geography, and other fields within social sciences and humanities have long suggested that the environments in which people live deeply influence their cultural value systems and practices. Shota Shibasaki, Ryosuke Nakadai, and Yo Nakawake have built on this idea, demonstrating that local ecological characteristics shape the appearance of trickster animals in folklore. Based on their finding and the SM3D (Serendipity-Mindsponge-3D) knowledge management framework, we discuss how the individuals’ or groups’ ability to create cultural products depends on the (...) availability and accessibility of information from the surrounding environment. Due to biodiversity loss and climate change, such valuable resources for cultural creativity have been diminished. Thus, it is crucial to adopt biodiversity preservation and climate action as fundamental values of a progressive and humane culture. Only then can we continue to preserve and enhance the creative cultural capacity of society. (shrink)

Conservation can occur anywhere regardless of scale, political jurisdiction, or landownership. We present a framework to help managers at protected areas practice conservation at the scale of relationships. We focus on relationships between stakeholders and protected areas and between managers and other stakeholders. We provide a synthesis of key natural resources literature and present a case example to support our premise and recommendations. The purpose is 4-fold: 1) discuss challenges and threats to conservation and protected areas; 2) outline a relationship-scale (...) approach to address conservation threats; 3) describe the tools and techniques that can be used to implement this approach; and 4) present a case example from rural Alaska, USA, to illustrate relationship-scale conservation. Our case example illustrates how aspects of this approach to conservation were applied to address a wildlife population decline. Tools needed to implement relationship-scale conservation include 1) collecting and documenting narratives of place; 2) measuring and monitoring trust and commitment; and 3) identifying and mitigating threats. We recommend that planners and managers, working with their research partners, redefine and refocus their goals and objectives to include these practices. Doing so will enable them to gain substantial applied knowledge about their stakeholders and foster and maintain place relationships as desired outcomes of conservation. The ultimate outcome is a better prognosis for long-term global survival of protected areas and biodiversity. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. (shrink)

This chapter introduces the two main philosophical questions that are raised by the prospect of extinct species being brought back from the dead—namely, the ‘Authenticity Question’ and the ‘Ethical Question’. It distinguishes different types of de-extinction, and different methods by which de-extinction can be accomplished. Finally, it examines the aims of wildlife conservation with a view to whether they are compatible with de-extinction, or not.