Researchers tracking social trends have discovered a remarkable labor-saving device called the computer. They sit down before the instrument, call up a search engine, enter a key word that they believe represents the trend, and count the number of articles aroused by that key word. They track these numbers over a period of time and even graph them. Those who dislike a certain concept are happy to report the concept's rise and fall. Such has occurred with two articles, one of (...) which appeared in CQ, reporting the rise and fall of medical futility. We are impressed with the power of this research methodology, which seems capable of eliminating concepts, even when our own more labor-intensive yet apparently less perceptive daily experience finds evidence of their existence all around us. (shrink)

Previous studies have documented the fallibility of attempts by surrogates and physicians to act in a substituted judgment capacity and predict end-of-life treatment decisions on behalf of patients. We previously reported that physicians misperceive their patients' preferences and substitute their own preferences for those of their patients with respect to four treatments: cardiopulmonary resuscitation (CPR) in the event of cardiac arrest, ventilator for an indefinite period of time, medical nutrition and hydration for an indefinite period of time, and hospitalization in (...) the event of pneumonia. (shrink)

Previous studies have documented the fallibility of attempts by surrogates and physicians to act in a substituted judgment capacity and predict end-of-life treatment decisions on behalf of patients. We previously reported that physicians misperceive their patients' preferences and substitute their own preferences for those of their patients with respect to four treatments: cardiopulmonary resuscitation in the event of cardiac arrest, ventilator for an indefinite period of time, medical nutrition and hydration for an indefinite period of time, and hospitalization in the (...) event of pneumonia. (shrink)

Schneiderman, Teetzel, and Gilmer offer an amusing but misleading response to my article on medical futility. Although I did make note of the falloff in citations to medical futility in Medline and Bioethicsline after 1995, my analysis focused on the precipitous rise in professional publications on the concept in the period from 1988 to 1995—a trend confirmed by the authors' own search results. I certainly did not argue, either explicitly or implicitly, that the discussion of medical futility was over. (...) I made limited use of this citation survey—to raise a question about what sparked so much professional debate after 1988. This seems to me an entirely appropriate methodology. (shrink)

Economics is probably the most subtle, precise and powerful of the social sciences and its theories have deep philosophical import. Yet the dominant alliance between economics and philosophy has long been cheerfully simple. This is the textbook alliance of neo-Classicism and Positivism, so crucial to the defence of orthodox economics against by now familiar objections. This is an unusual book and a deliberately controversial one. The authors cast doubt on assumptions which neo-Classicists often find too obvious to defend or, indeed, (...) to mention. They set out to disturb an influential concensus and to champion an unpopular cause. Although they go deeper into both philosophy and economics than is usual in interdisciplinary works, they start from first principles and the text is provokingly clear. This will be a stimulating book for all economic theorists and philosophers interested in the philosophy of science and social science. (shrink)

In this field guide, I distinguish five separate senses with which the term ‘mechanism’ is used in contemporary philosophy of science. Many of these senses have overlapping areas of application but involve distinct philosophical claims and characterize the target mechanisms in relevantly different ways. This field guide will clarify the key features of each sense and introduce some main debates, distinguishing those that transpire within a given sense from those that are best understood as concerning distinct senses. The ‘new mechanisms’ (...) sense is at the center of most of these contemporary debates and will be treated at greater length; subsequent senses of mechanism will be primarily distinguished from this one. In part I of this paper, I distinguish two senses of the term ‘mechanism’, both of which are explicitly hierarchical and nested in character, such that any given mechanism is comprised of smaller sub-mechanisms, in turn comprised of yet smaller sub-sub-mechanisms and so on. While both of the senses discussed here are anti-reductive, they differ in their focus on scientific practice versus metaphysics, in the degree of regularity they attribute to mechanisms, and in terms of their relationships to the discussions of mechanisms in the history of philosophy and science. (shrink)

With recent controversies surrounding the eligibility of athletes with disorders of sex development and hyperandrogenism, as well as continued discussion of the conditions transgender athletes must meet to compete in high-performance sport, a wide array of scholars representing a diverse range of disciplines have weighed in on both the appropriateness of classifying athletes into the female and male categories and the best practices of doing so. In response to cases of high-profile athletes’ sex being called into question, the International Olympic (...) Committee, the International Association of Athletics Federations, and the National Collegiate Athletics Association, among others, published or updated policies addressing who is eligible to compete in the women’s sport category and under what conditions. This paper addresses the areas in which philosophical reasoning and ethical analysis can contribute to reopened debates about the surveillance of the women’s category in sport. Emphasis is placed on determining where the onus of responsibility should fall for ensuring the new policies are followed. (shrink)

Even though the evidence‐based medicine movement (EBM) labels mechanisms a low quality form of evidence, consideration of the mechanisms on which medicine relies, and the distinct roles that mechanisms might play in clinical practice, offers a number of insights into EBM itself. In this paper, I examine the connections between EBM and mechanisms from several angles. I diagnose what went wrong in two examples where mechanistic reasoning failed to generate accurate predictions for how a dysfunctional mechanism would respond to intervention. (...) I then use these examples to explain why we should expect this kind of mechanistic reasoning to fail in systematic ways, by situating these failures in terms of evolved complexity of the causal system(s) in question. I argue that there is still a different role in which mechanisms continue to figure as evidence in EBM: namely, in guiding the application of population‐level recommendations to individual patients. Thus, even though the evidence‐based movement rejects one role in which mechanistic reasoning serves as evidence, there are other evidentiary roles for mechanistic reasoning. This renders plausible the claims of some critics of evidencebased medicine who point to the ineliminable role of clinical experience. Clearly specifying the ways in which mechanisms and mechanistic reasoning can be involved in clinical practice frames the discussion about EBM and clinical experience in more fruitful terms. (shrink)

This paper articulates an account of causation as a collection of information-theoretic relationships between patterns instantiated in the causal nexus. I draw on Dennett’s account of real patterns to characterize potential causal relata as patterns with specific identification criteria and noise tolerance levels, and actual causal relata as those patterns instantiated at some spatiotemporal location in the rich causal nexus as originally developed by Salmon. I develop a representation framework using phase space to precisely characterize causal relata, including their degree (...) of counterfactual robustness, causal profiles, causal connectivity, and privileged grain size. By doing so, I show how the philosophical notion of causation can be rendered in a format that is amenable for direct application of mathematical techniques from information theory such that the resulting informational measures are causal informational measures. This account provides a metaphysics of causation that supports interventionist semantics and causal modeling and discovery techniques. (shrink)

A finer-grained delineation of a given explanandum reveals a nexus of closely related causal and non- causal explanations, complementing one another in ways that yield further explanatory traction on the phenomenon in question. By taking a narrower construal of what counts as a causal explanation, a new class of distinctively mathematical explanations pops into focus; Lange’s characterization of distinctively mathematical explanations can be extended to cover these. This new class of distinctively mathematical explanations is illustrated with the Lotka-Volterra equations. There (...) are at least two distinct ways those equations might hold of a system, one of which yields straightforwardly causal explanations, but the other of which yields explanations that are distinctively mathematical in terms of nomological strength. In the first, one first picks out a system or class of systems, finds that the equations hold in a causal -explanatory way; in the second, one starts with the equations and explanations that must apply to any system of which the equations hold, and only then turns to the world to see of what, if any, systems it does in fact hold. Using this new way in which a model might hold of a system, I highlight four specific avenues by which causal and non- causal explanations can complement one another. (shrink)

Although Socrates’ use of induction and epagogic argumentation in Plato’s dialogues is well studied, scholarship on Platonic methodology lacks a clear account of Plato’s own view of epagōgē. In this paper, I refute Richard Robinson’s claim that Plato had no awareness of epagōgē, arguing that the “method of collection” serves as Plato’s theory of dialectical induction. Using the evidence of both the Statesman and the Sophist, I maintain that the abstraction characteristic of collection may be ‘purified’ of its empirical origins (...) in its dialectical application to the inquiry into forms. In addition to providing a unifying thread from Socratic to Platonic and, finally, Aristotelian epagōgē, this view also offers evidence for the consistency of dialectical methodology within the dialogues. (shrink)

A finer-grained delineation of a given explanandum reveals a nexus of closely related causal and non-causal explanations, complementing one another in ways that yield further explanatory traction on the phenomenon in question. By taking a narrower construal of what counts as a causal explanation, a new class of distinctively mathematical explanations pops into focus; Lange’s characterization of distinctively mathematical explanations can be extended to cover these. This new class of distinctively mathematical explanations is illustrated with the Lotka–Volterra equations. There are (...) at least two distinct ways those equations might hold of a system, one of which yields straightforwardly causal explanations, and another that yields explanations that are distinctively mathematical in terms of nomological strength. In the first case, one first picks out a system or class of systems, and finds that the equations hold in a causal–explanatory way. In the second case, one starts with the equations and explanations that must apply to any system of which the equations hold, and only then turns to the world to see of what, if any, systems it does in fact hold. Using this new way in which a model might hold of a system, I highlight four specific avenues by which causal and non-causal explanations can complement one another. _1_. Introduction _2._ Delineating the Boundaries of Causal Explanation _2.1._ Why construe causal explanation narrowly? The land of explanation versus grain-focusing _2.2._ Reasons to narrow the scope of causal explanation _3._ Broadening the Scope of Mathematical Explanation _4._ Lotka–Volterra: Same Model, Different Explanation Types _4.1._ General biocide in the Lotka–Volterra model _4.2._ Two ways a model can hold, yielding causal versus mathematical explanations _5._ Four Complementary Relationships between Mathematical and Causal Explanation _5.1._ Slight reformulations of explananda _5.2._ Causal distortion of idealized mathematical models _5.3._ Partial explanations requiring supplementation _5.4._ Explanatory dimensionality _6._ Conclusion. (shrink)

Throughout 2019, retired athletes Martina Navratilova, Sharron Davies, Kelly Holmes and Paula Radcliffe all spoke publically about what they perceive to b...

Humean accounts of laws are often contrasted with governing accounts, and recent developments have added pragmatic versions of Humeanism. This paper offers Mitchell's pragmatist, perspectival account of laws as a third option. The differences between these accounts come down to the role of modality. Mitchell's bottom-up account allows for subtle gradations of modal content to be conveyed by laws. The perspectival character of laws is not an accident or something to be eventually eliminated - it is part of how this (...) modal content is conveyed. I conclude with a discussion of the metaphysical commitments in Humeanism as requiring a perspectiveless view of the manifold from outside, and how Mitchell's situated account is better able to account for the substantive notion of possibility involved in scientific laws. (shrink)

In this field guide, I distinguish five separate senses with which the term ‘mechanism’ is used in contemporary philosophy of science. Many of these senses have overlapping areas of application but involve distinct philosophical claims and characterize the target mechanisms in relevantly different ways. This field guide will clarify the key features of each sense and introduce some main debates, distinguishing those that transpire within a given sense from those that are best understood as concerning two distinct senses. The ‘new (...) mechanisms’ sense is the primary sense from which other senses will be distinguished. In part II of this field guide, I consider three further senses of the term that are ontologically ‘flat’ or at least not explicitly hierarchical in character: equations in structural equation models of causation, causal-physical processes, and information-theoretic constraints on states available to systems. After characterizing each sense, I clarify its ontological commitments, its methodological implications, how it figures in explanations, its implications for reduction, and the key manners in which it differs from other senses of mechanism. I conclude that there is no substantive core meaning shared by all senses, and that debates in contemporary philosophy of science can benefit from clarification regarding precisely which sense of mechanism is at stake. (shrink)

Within the cognitive sciences, most researchers assume that it is the job of linguists to investigate how language is represented, and that they do so largely by building theories based on explicit judgments about patterns of acceptability – whereas it is the task of psychologists to determine how language is processed, and that in doing so, they do not typically question the linguists' representational assumptions. We challenge this division of labor by arguing that structural priming provides an implicit method of (...) investigating linguistic representations that should end the current reliance on acceptability judgments. Moreover, structural priming has now reached sufficient methodological maturity to provide substantial evidence about such representations. We argue that evidence from speakers' tendency to repeat their own and others' structural choices supports a linguistic architecture involving a single shallow level of syntax connected to a semantic level containing information about quantification, thematic relations, and information structure, as well as to a phonological level. Many of the linguistic distinctions often used to support complex syntactic structure are instead captured by semantics; however, the syntactic level includes some specification of “missing” elements that are not realized at the phonological level. We also show that structural priming provides evidence about the consistency of representations across languages and about language development. In sum, we propose that structural priming provides a new basis for understanding the nature of language. (shrink)

How regular do mechanisms need to be, in order to count as mechanisms? This paper addresses two arguments for dropping the requirement of regularity from the definition of a mechanism, one motivated by examples from the sciences and the other motivated by metaphysical considerations regarding causation. I defend a broadened regularity requirement on mechanisms that takes the form of a taxonomy of kinds of regularity that mechanisms may exhibit. This taxonomy allows precise explication of the degree and location of regular (...) operation within a mechanism, and highlights the role that various kinds of regularity play in scientific explanation. I defend this regularity requirement in terms of regularity’s role in individuating mechanisms against a background of other causal processes, and by prioritizing mechanisms’ ability to serve as a model of scientific explanation, rather than as a metaphysical account of causation. It is because mechanisms are regular, in the expanded sense described here, that they are capable of supporting the kinds of generalizations that figure prominently in scientific explanations. (shrink)

The reduction of grounding to causation, or each to a more general relation of which they are species, has sometimes been justified by the impressive inferential capacity of structural equation modelling, causal Bayes nets, and interventionist causal modelling. Many criticisms of this assimilation focus on how causation is inadequate for grounding. Here, I examine the other direction: how treating grounding in the image of causation makes the resulting view worse for causation. The distinctive features of causal modelling that make this (...) connection appealing are distorted beyond use by forcing them to fit onto grounding. The very inferential strength that makes causation attractive is only possible because of a narrow construal of what counts as a causal relation; as soon as that broadens, the inferential capacity markedly diminishes. Making causation suitable for application to grounding spoils what was appealing about causation for this task in the first place. However, grounding need not appeal to causation: causal modelling does not have exclusive claim to structural equation modeling or other formal techniques of modelling structure. I offer a case in favour of a different kind of metaphysical frugality, which tend towards narrow, more restrictive construals of relations like causation or grounding, because then each relation behaves more homogenously. This more homogenous behavior delivers stronger inferential power per relation even though there may be more relations to which one is committed. (shrink)

William James’ Principles of Psychology, in which he made famous the ‘specious present’ doctrine of temporal experience, and Edmund Husserl’s Zur Phänomenologie des inneren Zeitbewusstseins, were giant strides in the philosophical investigation of the temporality of experience. However, an important set of precursors to these works has not been adequately investigated. In this article, we undertake this investigation. Beginning with Reid’s essay ‘Memory’ in Essays on the Intellectual Powers of Man, we trace out a line of development of ideas about (...) the temporality of experience that runs through Dugald Stewart, Thomas Brown, William Hamilton, and finally the work of Shadworth Hodgson and Robert Kelly, both of whom were immediate influences on James (though James pseudonymously cites the latter as ‘E.R. Clay’). Furthermore, we argue that Hodgson, especially his Metaphysic of Experience (1898), was a significant influence on Husserl. (shrink)

Leuridan (2010) argued that mechanisms cannot provide a genuine alternative to laws of nature as a model of explanation in the sciences, and advocates Mitchell’s (1997) pragmatic account of laws. I first demonstrate that Leuridan gets the order of priority wrong between mechanisms, regularity, and laws, and then make some clarifying remarks about how laws and mechanisms relate to regularities. Mechanisms are not an explanatory alternative to regularities; they are an alternative to laws. The existence of stable regularities in nature (...) is necessary for either model of explanation: regularities are what laws describe and what mechanisms explain. (shrink)

I present three reasons why philosophers of science should be more concerned about violations of causal faithfulness (CF). In complex evolved systems, mechanisms for maintaining various equilibrium states are highly likely to violate CF. Even when such systems do not precisely violate CF, they may nevertheless generate precisely the same problems for inferring causal structure from probabilistic relationships in data as do genuine CF-violations. Thus, potential CF-violations are particularly germane to experimental science when we rely on probabilistic information to uncover (...) the DAG, rather than already knowing the DAG from which we could predict the right experiments to ‘catch out’ the hidden causal relationships. (shrink)

Twentieth century philosophers introduced the distinction between “objective rightness” and “subjective rightness” to achieve two primary goals. The first goal is to reduce the paradoxical tension between our judgments of what is best for an agent to do in light of the actual circumstances in which she acts and what is wisest for her to do in light of her mistaken or uncertain beliefs about her circumstances. The second goal is to provide moral guidance to an agent who may be (...) uncertain about the circumstances in which she acts, and hence is unable to use her standard moral principle directly in deciding what to do. This paper distinguishes two important senses of “moral guidance”; proposes criteria of adequacy for accounts of subjective rightness; canvasses existing definitions for “subjective rightness”; finds them all deficient; and proposes a new and more successful account. It argues that each comprehensive moral theory must include multiple principles of subjective rightness to address the epistemic situations of the full range of moral decision-makers, and shows that accounts of subjective rightness formulated in terms of what it would reasonable for the agent to believe cannot provide that guidance. (shrink)

Recently two distinct forms of rule-utilitarianism have been introduced that differ on how to measure the consequences of rules. Brad Hooker advocates fixed-rate rule-utilitarianism, while Michael Ridge advocates variable-rate rule-utilitarianism. I argue that both of these are inferior to a new proposal, optimum-rate rule-utilitarianism. According to optimum-rate rule-utilitarianism, an ideal code is the code whose optimum acceptance level is no lower than that of any alternative code. I then argue that all three forms of rule-utilitarianism fall prey to two fatal (...) problems that leave us without any viable form of rule-utilitarianism. (shrink)

Structural priming offers a powerful method for experimentally investigating the mental representation of linguistic structure. We clarify the nature of our proposal, justify the versatility of priming, consider alternative approaches, and discuss how our specific account can be extended to new questions as part of an interdisciplinary programme integrating linguistics and psychology as part of the cognitive sciences of language.

Although justice is a central principle in clinical ethics, work that centers social justice is often marginalized in clinical ethics. In addition to institutional barriers that may be preventing clinical ethicists from becoming the activists that Meyers argues we should be, we must also recognize the barriers embedded in the field of clinical ethics itself. As clinical ethicists, we have an opportunity to support anti‐racism work in particular by altering our own organizational structures to be more inclusive and reflective of (...) the Black, Indigenous, and other communities of color we serve, enhancing clinical ethics education and training by making critical theories foundational, and decolonizing our clinical ethics consultation tools and practices. (shrink)

Background In end-of-life situations, the phrase “do everything” is sometimes invoked by physicians, patients, or substitute decision-makers, though its meaning is ambiguous. We examined instances of the phrase “do everything” in the archive of the Ontario Consent and Capacity Board in Canada, a tribunal with judicial authority to adjudicate physician–patient conflicts in order to explore its potential meanings. Methods We systematically searched the CCB’s online public archive from its inception to 2018 for any references to “do everything” in the context (...) of critical care medicine and end-of-life care. Two independent assessors reviewed decisions, collected characteristics, and identified key themes. Results Of 598 cases in the archive, 41 referred to “do everything” in end-of-life situations. The phrase was overwhelmingly invoked by SDMs, typically to advocate for life-prolonging measures that contradicted physician advice. Physicians generally related “doing everything” to describe the interventions they had already performed, using it to recommend focusing on patients’ quality of life. SDMs were generally reluctant to accept death, whereas physicians found prolonging life at all costs to be morally distressing. The CCB did not interpret appeals to “do everything” legally but followed existing laws by deferring to patients’ prior wishes whenever known, or to concepts of “best interests” when not. The CCB generally recommended against life-prolonging measures in these cases, focusing on patients’ “well-being” and “best interests.” Conclusions In this unique sample of cases involving conflict surrounding resuscitation and end-of-life care, references to “do everything” highlighted conflicts over quantity versus quality of life. These appeals were associated with signs of cognitive distress on the behalf of SDMs who were facing the prospect of a patient’s death, whereas physicians identified moral distress related to the prolongation of patients’ suffering through their use of life-sustaining interventions. This divergence in perspectives on death versus suffering was consistently the locus of conflict. These findings support the importance of tools such as the Serious Illness Conversation Guide that can be used by physicians to direct conversations on the patients’ goals, wishes, trade-offs, and to recommend a treatment plan that may include palliative care. Trial Registration Not applicable. (shrink)

Geoengineering has been broadly and helpfully defined as “the intentional manipulation of the earth's climate to counteract anthropogenic climate change or its warming effects” (Corner and Pidgeon , 26). Although there exists a rapidly growing literature on the ethics of geoengineering, very little has been written about its gender dimensions. The authors consider four contexts in which geoengineering appears to have important gender dimensions: (1) the demographics of those pushing the current agenda, (2) the overall vision of control it involves, (...) (3) the design of the particular technologies, and (4) whom geoengineering will most affect and benefit. After detailing these four gender dimensions, we consider three ways in which the geoengineering discourse could be enriched if it became more sensitive to issues of gender. These include increasing the focus on the concrete other, recognizing the socially transformative potential of geoengineering technologies, and engaging in value-sensitive design. Although ultimately remaining agnostic on the desirability of geoengineering, the paper brings gender considerations into a discussion from which they have been conspicuously absent. (shrink)

Ellis argues that certain essential properties of objects in the world not only determine the nature of these objects but also how they will behave in any situation. In this paper I will critique Ellis's essentialism from the perspective of the philosophy of chemistry, arguing that our current knowledge of chemistry in fact does not lend itself to essentialist interpretations and that this seriously undercuts Ellis's project. In particular I will criticize two key distinctions Ellis draws between internal vs. external (...) properties and essential vs. accidental properties, showing that at the chemical level such distinctions are insupportable. If essential properties only exist at the level of sub-atomic physics, then Ellis's hopes that essentialism will provide a theoretical basis for a philosophy of chemistry are at best hopes for a very distant future, since the argument that chemical structure and dynamics can be explained at the quantum level derived is purely from analogy to much simpler systems than those chemists actually study. This suggests that we have very little scientific evidence that scientific essentialism is a viable ontology. †To contact the author, please write to: Department of Philosophy, University of Notre Dame, Notre Dame, IN 46556; e-mail: [email protected]. (shrink)

Given the technological constraints of long-duration space travel and planetary settlement, off-Earth humans will likely need to employ food systems very different from their terrestrial counterparts, and newly emerging food technologies are being developed that will shape novel food systems in these off-Earth contexts. Projected off-Earth food systems may therefore potentially “alienate” their users in new ways compared to Earth-based food systems. They will be susceptible to alienation in ways that are similar to such potential on Earth, where there are (...) points of overlap between off-Earth food systems and any of the multitudes of ways in which food systems on Earth are structured. They will also be susceptible to new forms of alienation, as we encounter scenarios that are genuinely structurally novel to humanity. These are especially important to consider since there are comparatively fewer analyses of these food systems where they differ from existing ones. We propose five non-exhaustive sources of value beyond nutrition our individual relationships with a food may possess: gustatory, social, cultural, epistemic, and authorial value. Using these, we offer examples of ways in which an off-Earth food system may exacerbate or alleviate alienation for humans in long-term off-Earth food systems. (shrink)

This chapter examines the philosophical discussion concerning the relationship between time, memory, attention, and consciousness, from Locke through the Scottish Common Sense tradition, in terms of its influence on James' development of the specious present doctrine. The specious present doctrine is the view that the present moment in experience is non punctate, but instead comprises some nonzero amount of time; it contrasts with the mathematical view of the present, in which the divide between past and future is merely a point (...) or a line with no thickness. The anonymous source for the term 'specious present' is revealed as a retired businessman-turned-amateur philosopher. The more likely source for the idea itself is a little-known philosopher, Shadworth Hollway Hodgson, who was not merely a significant influence on James but also on Husserl's development of the tripartite account of internal time consciousness. I conclude by demonstrating how James' changing views on the relationship between concepts and experience meant that by the later period of his writings, including those in which he develops his own views on pragmatism, James would have not merely noted the contrast between a mathematical conception of the present and our actual experience of it, he would have taken a further step and condoned the thick experience of the present as demonstrating the inadequacy of the intellectualized mathematical characterization. (shrink)

What should we do if we cannot figure what morality requires of us? Holly M. Smith argues that the best moral codes solve this problem by offering two tiers, one of which tells us what makes acts right and wrong, and the other of which provides user-friendly decision guides. She opens a path towards resolving a deep problem of moral life.

This paper explores the degree of privacy athletes can expect and demand in the era of genetic technology in sport. Detecting genetic enhancements in sport, and consequently doping violations, using genetic tests is problematic because testing requires access to athletes' genetic information, and accessing genetic information creates many potential privacy issues and concerns throughout the world. Whether it is morally acceptable to subject athletes to the tests used to detect genetic modifications in sport is taken up in this paper, and (...) I argue that the elite sport movement faces an ethical dilemma since rules prohibit athletes from utilising certain substances, methods and procedures, but the testing methods needed to ensure compliance with the rules are controversial and at odds with a reasonable expectation of privacy. (shrink)