Heart donation after circulatory determination of death (DCDD) expands the donor pool but requires careful ethical grounding, particularly regarding the determination of death. This article affirms the legitimacy of brain death as a medically and ethically valid form of death, emphasizing that the irreversible cessation of brain function remains the foundational criterion. Building upon the framework proposed by Bernat and Dalle Ave, the essay promotes the concept of Donation after Brain Circulation Determination of Death (DBCDD), which ensures death is defined (...) by the permanent cessation of brain circulation, leading inevitably to the loss of all brain function. It argues for the necessity of safeguards in DCDD protocols, including strict verification of systemic circulatory arrest and clear exclusion of cerebral reperfusion. Rather than undermining the legitimacy of DCDD, these standards uphold the integrity of brain‐based death determination, reinforce the dead donor rule, and safeguard public trust. This approach unifies death determination under the brain criterion across all clinical pathways. (shrink)

This paper explores a distinction among causal relationships that has yet to receive attention in the philosophical literature, namely, whether causal relationships are reversible or irreversible. We provide an analysis of this distinction and show how it has important implications for causal inference and modeling. This work also clarifies how various familiar puzzles involving preemption and over-determination play out differently depending on whether the causation involved is reversible.

In a seminal article C. Henry (1974) presented the irreversibility effect, which pointed out that under uncertainty, the optimal sequence of decisions depends on not only the payoffs, but also the flexibility, in terms of availability of future options, associated with each decision. But the irreversibility effect pertained to certain particular conditions and definitions. In this paper, a more general model is developed to re-examine the notion of an irreversible decision, its relation with flexibility and the irreversibility (...) effect. It is shown through two propositions that the irreversibility effect need not hold always and the notion of irreversibiity can be used only under certain circumstances to derive the optimal sequence of decisions ex-ante. (shrink)

This paper studies the influence of agency conflicts on the irreversibility effect. Using a dynamic variant of the static Baron and Myerson :911–930, 1982) adverse selection model, we characterize under which circumstances the irreversibility effect arises in the presence and absence of an agency conflict. In particular, we find that in the presence of an agency conflict the irreversibility effect arises in more circumstances than in the standard first-best analysis that abstracts from agency problems.

There has been growing concern about whether individuals who satisfy neurological criteria for death or who become non-heart-beating organ donors are really dead. This concern has focused on the issue of the potential for recovery that these individuals may still have and whether their conditions are irreversible. In this article I examine the concepts of potentiality and irreversibility that have been invoked in the discussions of the definition of death and non-heart-beating organ donation. I initially focus on the recent (...) challenge by D. Alan Shewmon to accepting any neurological criterion of death. I argue that Shewmon relies on a problematic and unrealistic concept of potentiality, and that a better, more realistic concept of potentiality is consistent with accepting a neurological criterion for death. I then turn to an analysis of how the concept of irreversibility has been used in discussion of non-heart-beating organ donation. Similarly, I argue that some participants in this discussion have invoked a problematic and unrealistic concept of irreversibility. I then propose an alternative, more realistic account of irreversibility that explains how "irreversibility" should be understood in the definition and criteria of death. (shrink)

Professor Cole is correct in his conclusion that the University of Pittsburgh Medical Center (UPMC) protocol does not violate requirements of "irreversibility" in criteria of death, but wrong about the reasons. "Irreversible" in this context is best understood not as an ontological or epistemic term, but as an ethical one. Understood that way, the patient declared dead under the protocol is "irreversibly" so, even though resuscitation by medical means is still possible. Nonetheless, the protocol revives difficult questions about our (...) concept of death. (shrink)

In this paper I examine Albert’s (2000) claim that the low entropy state of the early universe is sufficient to explain irreversible thermodynamic phenomena. In particular, I argue that conditionalising on the initial state of the universe does not have the explanatory power it is presumed to have. I present several arguments to the effect that Albert’s ‘past hypothesis’ alone cannot justify the belief in past non-equilibrium conditions or ground the veracity of records of the past.

Irreversible generalism, the view that reasons given for the evaluation of art are general and do not admit of exceptions, is defended from the criticisms levelled against it by George Dickie in ‘Reading Sibley’. The authors' view that Frank Sibley adhered to a form of reversible generalism, the view that reasons given for the evaluation of art are general but can sometimes become reasons to disvalue artworks, according to which there a criterion for distinguishing valenced from neutral aesthetic properties, is (...) also defended. (shrink)

We argue that turbulent irreversibility is best explained as an asymptotic feature of a singular inviscid limit—a reclassification of admissible entities and balances at ν→0—rather than as a mere residual effect of molecular viscosity. Tracing a conceptual line from Euler and Kármán–Howarth to Onsager, Duchon–Robert, Kato/Prandtl, and modern convex integration results, we show that the limit theory reclassifies the admissible entities: from smooth Euler fields (energy conserving) to rough weak solutions equipped with a positive defect measure in the energy (...) balance. The constant inter-scale process (energy flux) observed at high-Reynolds number therefore persists at ν=0 as a structural feature of the limit ontology. We articulate three selection principles—the local energy inequality, the exact third-order law, and scale-locality—as ontological constraints that reconcile mathematical non-uniqueness with physical uniqueness. A brief conceptual history clarifies how the arrow of time in turbulence emerged through successive shifts of entities and invariants, and a comparison with other singular limit explanations (Boltzmannian irreversibility, shocks, renormalization) situates the account within general foundations of physics. Methodologically, we recast LES/closures as asymptotic mediators validated by flux plateaus and viscosity-free diagnostics, not microscopic subgrid fidelity. (shrink)

I discuss a broad critique of the classical approach to the foundations of statistical mechanics (SM) offered by N. S. Krylov. He claims that the classical approach is in principle incapable of providing the foundations for interpreting the "laws" of statistical physics. Most intriguing are his arguments against adopting a de facto attitude towards the problem of irreversibility. I argue that the best way to understand his critique is as setting the stage for a positive theory which treats SM (...) as a theory in its own right, involving a completely different conception of a system's state. As the orthodox approach treats SM as an extension of the classical or quantum theories (one which deals with large systems), Krylov is advocating a major break with the traditional view of statistical physics. (shrink)

In the case of the irreversibly comatose patient, though no personal consciousness remains, some moral duty is owed the remaining biological life. Such an ending to human life, if pathetic, is also both intelligible and meaningful in a biological and evolutionary perspective. By distinguishing between the human subjective life and the spontaneous objective life, we can recognize a naturalistic principle in medical ethics, contrary to a current tendency to defend purely humanistic norms. This principle has applications in clinical care in (...) the definition of death, in the use of life support therapy, in distinguishing ordinary from extraordinary therapy, in evaluating euthanasia, and in the extent of appropriate medical intervention in terminal cases. CiteULike Connotea Del.icio.us What's this? (shrink)

This chapter offers three reasons for trying to avoid some irreversible losses. First, there is a prudential reason for avoiding irreversible loss in order to keep options open in the future in the face of uncertainty. Second, humans have reasons to care about the preservation of some goods, even beyond their own life. Third, present generations may have duties towards future generations to avoid some irreversible losses, though spelling out such theories of intergenerational ethics or justice is challenging. Finally, the (...) chapter responds to the objection that – in a certain sense – all processes are irreversible and the notion therefore empty. A sensible conception of irreversibility is offered that avoids this concern. (shrink)

Uffink and Valente claim that there is no time-asymmetric ingredient that, added to the Hamiltonian equations of motion, allows to obtain the Boltzmann equation within the Lanford’s derivation. This paper is a discussion and a reply to that analysis. More specifically, I focus on two mathematical tools used in this derivation, viz. the Boltzmann–Grad limit and the incoming configurations. Although none of them are time-asymmetric ingredients, by themselves, I claim that the use of incoming configurations, as taken within the B–G (...) limit, is such a time-asymmetric ingredient. Accordingly, this leads to reconsider a kind of Stoßzahlansatz within Lanford’s derivation. (shrink)

The popularization of the term “clinical death” for the absence of vital signs suggests the possibility of a radical change in our understanding of death. While death used to be considered something that we do not have the power to reverse, contemporary optimism suggests that we may be able to restore life to a dead organism. In this article, I examine how the term “death” is used today to clarify what kind of irreversibility we ought to assign to it. (...) I conclude that the kind of irreversibility closest to our concept of death is one that depends on implicit metaphysical commitments: we generally treat death as though it were metaphysically irreversible, and therefore not reversible by us. (shrink)

Following the foundational axiomatization of intelligence in Version 1.2 (Foundations) and the subsequent formalization of dynamic resolution in Version 1.2 (Dynamics), this paper presents the geometric and topological synthesis of the Cognitional Mechanics (CM) framework. -/- By establishing a strict correspondence with matrix mechanics, we define the semantic state space as an Irreversible Manifold, in which intelligence evolves through non-commutative operation sequences. The commutation relation [A, B] ≠ 0 dictates the irreversible curvature of the manifold. The operational limit variable C(W), (...) previously introduced as a dynamic boundary, is re-characterized here as the catalyst for Topological Surgery—the mechanical realization of the "Logical Leap." -/- The central contribution of this work is the deconstruction of the Global Isotropy of artificial systems. We demonstrate that while artificial intelligence constitutes an advanced isotropic void of potentiality, the "Symmetry Breaking" induced by the human will (W) acts as the primary operator injecting singular inhomogeneity into the manifold. This process establishes intelligence as an externalized, controllable mechanics of the human mind, fully governed by rigorous geometric-operational laws. (shrink)

We suggest that some general questions of irreversibility and of quasi-Equilibrium vs. non-Equilibrium configurations (terminology is explained in the text), with respect to both biophysical and physical structures, can be clarified by generalizing results from investigations of stellar structure in relation to its environment. Such work has evolved from considerations of the stellar atmosphere as a transition zone between the quasi-Equilibrium stellar interior and the non-Equilibrium interstellar medium. As opposed to suggestions of irreversibility originating in the large (Gal-Or, (...) e.g.), we suggest that the origin is local, in coupling between different storage modes for matter and energy. In contract to suggestions of non-Equilibrium biophysical structures arising in fluctuations from a quasi-Equilibrium state (Prigogineet al.), we suggest that they arise via condensations within a non-Equilibrium, steady-state, unstable environment. Generalization from stellar prototype studies of the process of such concentration indicates that the general process of forming structures in the Universe follows a hierarchy of such greater degree ofEquilibrium concentrations formed in lower degree ofEquilibrium environments. (shrink)

We discuss Boltzmann’s probabilistic explanation of the second law of thermodynamics providing a comprehensive presentation of what is called today the typicality account. Countering its misconception as an alternative explanation, we examine the relation between Boltzmann’s H-theorem and the general typicality argument demonstrating the conceptual continuity between the two. We then discuss the philosophical dimensions of the concept of typicality and its relevance for scientific reasoning in general, in particular for understanding the reduction of macroscopic laws to microscopic laws. Finally, (...) we reply to various common criticisms of the typicality account. (shrink)

Is the opposition to circumcision partly driven by cultural prejudices?In this issue of the Journal of Medical Ethics you can read a minisymposium on circumcision, mainly dealing with the circumcision of male children at an age where they cannot consent, but also touching upon issues of female genital mutilation.When reading the papers I found it strange, but of course not really surprising given its symbolic importance, that we are so worried about interventions on the male penis. Why are we not (...) equally worried about other irreversible bodily and mental interventions to which parents subject their children? I will not dwell on the irreversible mental imprinting, apart from mentioning that upon becoming a father I was amused to find that certain Danish lullabies and children’s rhymes had apparently been stored in my mind for the last 40 …. (shrink)

It is a remarkable fact that all processes occurring in the observable universe are irre- versible, whereas the equations through which the fundamental laws of physics are formu- lated are invariant under time reversal. The emergence of irreversibility from the funda- mental laws has been a topic of consideration by physicists, astronomers and philosophers since Boltzmann's formulation of his famous \H" theorem. In this paper we shall discuss some aspects of this problem and its connection with the dynamics of (...) space-time, within the framework of modern cosmology. We conclude that the existence of cosmological horizons allows a coupling of the global state of the universe with the local events deter- mined through electromagnetic processes. (shrink)

I. Prigogine has proposed, and the writings of N. S. Krylov to some extent suggest, a novel and unorthodox solution to foundational problems in statistical mechanics. In particular, the view claims to offer new insight into two interconnected problems: understanding the role of probability in physics, and that of reconciling the irreversibility of physical processes with the temporal symmetry of dynamical theories. The approach in question advocates a conception of the state of a system which incorporates features of the (...) quantum mechanical state concept in a context, classical statistical mechanics, where quantum considerations are generally considered to be irrelevant. I examine the plausibility of this new approach by offering an analysis of the various notions of state employed in modern physics. ;In the first chapter, I analyze the conceptual connections between dynamical laws and the nature of a system's state. I argue that laws and states are correlative. In constructing dynamical theories one does not start with a fixed or pre-determined state concept. Neither is one given the laws of the theory from which the conception of state is derived. Rather, we get the law/state structure as a "package." In light of this general analysis, I next examine the notion of state employed in the quantum theory. Here I consider a variety of conceptions of quantum states and assess their ability to answer the "paradoxes" of quantum theory. I pay particular attention to the role of probability and related restrictions on the realization of certain states. The new approach to statistical mechanics proposes to exploit similar restrictions on states in order to resolve the irreversibility problem. But is this unorthodox approach viable? In the final four chapters, I offer a detailed critique of this approach, examining the plausibility of the radical reworking of the state concept. I argue that while some important progress can be made, certain old puzzles remain, and new and difficult ones arise--ones which raise serious doubts about the ultimate success of this particular approach. I conclude, however, by arguing that such radical proposals are not unmotivated; and that novel and unorthodox proposals concerning the foundations of statistical mechanics must be taken seriously. (shrink)

The irreversibility effect implies that a decision maker who neglects the prospect of receiving more complete information at later stages of a sequential decision problem will in certain cases too easily take an irreversible decision, as he ignores the existence of a positive option value in favour of reversible decisions. This option value represents the decision maker's flexibility to adapt subsequent decisions to the obtained information. In this paper we show that the economic models dealing with irreversibility as (...) used in environmental and capital investment decision making can be extended to emergency response decisions that produce important irreversible effects. In particular, we concentrate on the decision whether or not to evacuate an industrial area threatened by a possible nuclear accident. We show in a simple two-period evacuation decision model that non-optimal conclusions may be drawn when evacuation is regarded as a `now or never decision'. The robustness of these results is verified by means of a sensitivity analysis of the various model parameters. The importance of `options thinking' in this decision context is illustrated in an example. (shrink)

There are currently two legally established criteria for death: the irreversible cessation of circulation and respiration and the irreversible cessation of neurologic function. Recently, there have been technological developments that could undermine the irreversibility requirement. In this paper, I focus both on whether death should be identified as an irreversible state and on the proper scope of irreversibility in the biological definition of death. In this paper, I tackle the distinction between the commonsense definition of death and the (...) biological definition of death to show that even the commonsense concept of death is specified by biological facts. Resting on this argument, I argue that any definition of death is a posteriori. Thus, irreversibility is part of any definition of death because the actual phenomenon of death is irreversible. In addition, I show that the proper domain of irreversibility in a definition of death is circumscribed by physical possibilities and that irreversibility in the definition of death refers to current possibilities for the reversal of relevant biological processes. I conclude that, despite recent technological advancements, death is still irreversible. (shrink)

The transition from unitary, reversible von Neumann-Everett quantum processes to non-unitary, irreversible processes and measurements is explored through infinite tensor products interpreted as nested, chained, or iterated Wigner’s friend scenarios. Infinite tensor products can disrupt unitary equivalence through sectorization and factorization, drawing parallels to concepts from real analysis, recursive mathematics, and statistical physics.

As soon as 'modernity' was defined as a particular way of con ceiving of time, the questions of tempo rality came to be situated at the heart of the ongoing debate regarding the legitimacy or illegitimacy of the 'modern age'. This has, in turn, readily led to a no less passionate search for the assessment of modernity's foundations which are thought to rest in its typical sense of experiencing temporality. This polemic instance, however, involves polarized perspectives and the consequent risk, (...) always present in dichotomous approaches, of oversimplifying the concepts at stake and smoothing over the intricacies of their history and meaning. Does there really exist something like a ' time of modernity'? This is the central question that the present article examines. 1 Key Words: evolution • modemity • philosophy of history • time irreversibility. (shrink)

In their target article, Cohen and Marks (2025) argue that recognizing something as exceptional is a contextual matter. The authors consider the question of whether psychedelics are exceptional by...

The distinction between the "permanent" (will not reverse) and "irreversible" (cannot reverse) cessation of functions is critical to understand the meaning of a determination of death using circulatory–respiratory tests. Physicians determining death test only for the permanent cessation of circulation and respiration because they know that irreversible cessation follows rapidly and inevitably once circulation no longer will restore itself spontaneously and will not be restored medically. Although most statutes of death stipulate irreversible cessation of circulatory and respiratory functions, the accepted (...) medical standard is their permanent cessation because permanence is a perfect surrogate indicator for irreversibility, and using it permits a more timely declaration. Therefore, patients properly declared dead in donation after circulatory death (DCD) protocols satisfy the requirements of death statutes and do not violate the dead donor rule. The acronym DCD should represent organ "donation after circulatory death" to clarify that the death standard is the permanent cessation of circulation, not heartbeat. Heart donation in DCD does not retroactively negate the donor's death determination because circulation has ceased permanently. (shrink)

Irreversibility, it is claimed, is a much broader concept than is entropy increase, as is shown by the occurrence of certain processes which are irreversible without seeming to involve any intrinsic entropy change. These processes include the spreading outwards into space of particles, or of radiation, and they also include certain biological and mental phenomena. For instance, the irreversible and treelike branching which is characteristic of natural evolution is not entropic when it is considered in itself—i.e. in abstraction from (...) accompanying biochemical and physiological activity. What appears to be the common feature of all forms of irreversibility is the fanning out of trajectories, new entities or new states, in the temporal direction towards the future. (shrink)

The aim of this paper is to analyze time-asymmetric quantum mechanics with respect of its validity as a non time-reversal invariant, time-asymmetric theory as well as of its ability to determine an arrow of time.

The aim of this paper is to analyze time-asymmetric quantum mechanics with respect to the problems of irreversibility and of time's arrow. We begin with arguing that both problems are conceptually different. Then, we show that, contrary to a common opinion, the theory's ability to describe irreversible quantum processes is not a consequence of the semigroup evolution laws expressing the non-time-reversal invariance of the theory. Finally, we argue that time-asymmetric quantum mechanics, either in Prigogine's version or in Bohm's version, (...) does not solve the problem of the arrow of time because it does not supply a substantial and theoretically founded criterion for distinguishing between the two directions of time. (shrink)

Should the process of ecological restoration be considered a type of moral reparation? In a recent issue of this journal, Ben Almassi (2017) has argued that ecological restoration should be understood as a moral repair, i.e., as "a model for rebuilding the moral conditions of relationships" (20). Ideas of restorative justice and moral repair are appropriate to address human injustice and wrongdoing. But these concepts are vacuous and lose their meaning when addressing the ethics of human activities regarding the natural (...) world because of the essential character of the restoration process: the replacement or substitution of new entities for pre-existing entities in an attempt to reverse the irreversible. At best, the idea of moral reparations to nature is a weak metaphor with no practical efficacy; at worst, it totally misconceives the relationship between human activity and the natural environment in the process of ecological restoration and provides yet another dangerous and disingenuous justification of human arrogance and domination of the natural world. In the guise of the act of moral reparations, humans are instead attempting to assume the powers of God, to control the natural and human world. My previous criticisms of the ethics and meaning of ecological restorations—especially regarding the substitution of new individuals and the artifactual nature of restorations—can be used to undermine Almassi's thesis of moral repair as a goal of ecological restoration practice. In addition an analysis of the Book of Job in the Old Testament demonstrates that not even God—much less humans—can restore and replace what has been destroyed. (shrink)

At the fundamental level, physical laws are largely time-reversible. Yet the macroscopic world exhibits a clear and persistent arrow of time. This essay argues that irreversibility arises from the loss of accessible information in real, open systems. This work is a step in a broader exploration of the limits of knowability.

In the Second Analogy of Experience, Kant discusses that the concept of causality is necessary for the experience of an objective succession (a succession of states where state A is followed by state B), where the experience is a cognition that consists of judgment and perception. The perception that corresponds to the cognition of objective succession, for Kant, is an irreversible order of perceptions where the perception of state A (Ap) is necessarily followed by the perception of state B (Bp). (...) But what role does the concept of causality play in determining this irreversible order of perceptions? James Hutton thinks that the concept of causality determines this irreversible order of perceptions through its logical form. The logical form of the concept of causality is a hypothetical conditional of the form ‘if X (cause), then objective succession obtains’. For this reason, when one judges that X obtains, one is inferentially necessitated to judge that AB obtains and to place Ap prior to Bp. I reject his proposal via two objections: 1) Hutton fails to establish that one must have any perceptions at all, and 2) even if one has perceptions, the order of perceptions that result from his account is contingent. (shrink)

Singer claims that there are two ways of challenging the fact that brain-dead patients, from whom organs are usually retrieved, are in fact biologically alive. By means of the first, the so called dead donor rule may be abandoned, opening the way to lethal organ donation. In the second, it might be posited that terms such as “life” and “death” do not have any primary biological meaning and are applicable to persons instead of organisms. This second possibility permits one to (...) acknowledge that brain-dead patients are deceased because they are irreversibly unconscious. In the commentary which follows, I will argue that Singer’s second option is preferable since it (a) provides a higher amount of organs available for transplant, and (b) is better suited to the meaning of “death” which occurs in ordinary language. I will also defend such a concept of death against the objections raised by Michael Nair-Collins in the article Can the brain-dead be harmed or wronged? On the moral status of brain death and its implications for organ transplantation. (shrink)

The paper examines the meaning of irreversibility in the context of moral philosophy. It argues that acts or events appear (ir-)reversible only under specific descriptions (while there is room for reasonable argument about which descriptions are adequate). It compares irreversibility-claims about natural and about moral harm and discusses the significance and theory dependence of irreversibility claims in various contexts of practical reasoning.

Most definitions of death – whether cardiopulmonary, whole brain and brain stem, or just upper brain – include an irreversibility condition. Cessation of function is not enough to declare death. Irreversibility should be limited to an organism's ability to ‘restart’ itself after vital organs have ceased to function. However, this would mean that every hour people who cannot be revived without the intervention of medical personnel and their technology are coming back from the dead. However, the alternative of (...) irreversibility being dependent upon technology will lead to even more counterintuitive results such as: some people are dead at a particular time and place, but others in more technologically advanced eras and locations are alive despite their being in identical physical states; in the future, millions of cryogenically frozen human beings could spend centuries in a non–dead state because of the future technological breakthroughs; or large numbers of ‘frozen’ people are dead for aeons but coroners are not able to declare them so because they are unaware of what biological conditions science will never be able to reverse. So death should be defined only in non–relational biological terms with a self–starting condition similar to that once advocated by Lawrence Becker. (shrink)

After reviewing recent literature from physics and philosophy, it is concluded that we are still far from having a satisfying explanation of the nature and origins of irreversibility. It is proposed that the most fruitful approach to this problem is to concentrate on conditions needed for a rigorous derivation of the Boltzmann equation.

It has been a longstanding problem to show how the irreversible behaviour of macroscopic systems can be reconciled with the time-reversal invariance of these same systems when considered from a microscopic point of view. A result by Lanford shows that, under certain conditions, the famous Boltzmann equation, describing the irreversible behaviour of a dilute gas, can be obtained from the time-reversal invariant Hamiltonian equations of motion for the hard spheres model. Here, we examine how and in what sense Lanford’s theorem (...) succeeds in deriving this remarkable result. Many authors have expressed different views on the question which of the ingredients in Lanford’s theorem is responsible for the emergence of irreversibility. We claim that these interpretations miss the target. In fact, we argue that there is no time-asymmetric ingredient at all. (shrink)

Two distinct conceptions for the relation between reversible, time-reversal invariant laws of nature and the irreversible behavior of physical systems are outlined. The standard, extrinsic concept of irreversibility is based on the notion of an open system interacting with its environment. An alternative, intrinsic concept of irreversibility does not explicitly refer to any environment at all. Basic aspects of the two concepts are presented and compared with each other. The significance of the terms extrinsic and intrinsic is discussed.

The concept of irreversibility is central in several disciplines, from physics to biology and economics, as well as in many philosophical disputes. Yet, it is seldom clearly defined. In this article, it is argued that the thermodynamic framework with its concept of entropy – allegedly the hallmark of irreversibility – offers a formal framework for a thorough conceptualisation of irreversibility based on three (generic) parameters: (1) the openness of the systems and the possible interventions, (2) the (acceptable) (...) equivalence of the final state, and (3) the timeframe. Its usefulness for socio-ecological systems, and hence for sustainable development and sustainability science, will be shown by presenting how these generic parameters can be applied and interpreted in topics such as the precautionary principle, climate change mitigation and environmental aesthetics. (shrink)

An extension of the hypothetical experiment of Szilard, which involved the action of a one-molecule gas in an isolated isothermal system, is developed to illustrate how irreversibility may arise out of Brownian motion. As this development requires a consideration of nonmolecular components such as wheels and pistons, the thought-experiment is remodeled in molecular terms and appears to function as a perpetuum mobile.

One of the characteristic features of our time is the growth of its historical sense. The reason for this development is clear : we have lived more history than any other epoch in the evolution of mankind. In the past, during that short period of historical stability which—cum grano salis— characterized the forty-three years between the French-German War of 1870-71 and World War I, a person could live without being interested in history. In our days such an attitude is no (...) longer possible. We may try in vain to take no interest in history. History takes interest in us, in each of us. The last half-century showed us that to understand history is of equal importance to those who make it and to those who endure it. After having gone through two world wars and being confronted with the threat of a third one, people of my generation finally learned to understand that history is a perpetual collective becoming, of which each individual is, willy-nilly, a part. At the cost of great sacrifices we have acquired a new sense unknown to our fathers : a historical sense which guides us in life. As the seagull has a sense for meteorological storms, man, in the middle of the twentieth century, has developed a sense for historical storms : he feels the coming of wars and revolutions. (shrink)