Oaksford and Chater (1994) proposed to analyse the Wason selection task as an inductive instead of a deductive task. Applying Bayesian statistics, they concluded that the cards that participants tend to select are those with the highest expected information gain. Therefore, their choices seem rational from the perspective of optimal data selection. We tested a central prediction from the theory in three experiments: card selection frequencies should be sensitive to the subjective probability of occurrence for individual cards. In Experiment 1, (...) expected frequencies of the p- and the q-card were manipulated independently by concepts referring to large vs. small sets. Although the manipulation had an effect on card selection frequencies, there was only a weak correlation between the predicted and the observed patterns. In the second experiment, relative frequencies of individual cards were manipulated more directly by explicit frequency information. In addition, participants estimated probabilities for the four logical cases and of the conditional statement itself. The experimental manipulations strongly affected the probability estimates, but were completely unrelated to card selections. This result was replicated in a third experiment. We conclude that our data provide little support for optimal data selection theory. (shrink)
Sober and Wilson have recently claimed that evolutionary theory can do what neither philosophy nor experimental psychology have been able to, namely, "break the deadlock" in the egoism vs. altruism debate with an argument based on the reliability of altruistic motivation. I analyze both their reliability argument and the experimental evidence of social psychology in favor of altruism in terms of the folk-psychological "laws" and inference patterns underlying them, and conclude that they both rely on the same patterns. I expose (...) the confusions that have led Sober and Wilson to defend a reliability argument while rejecting the experimental evidence of social psychology. (shrink)
Views on the evolution of altruism based upon multilevel selection on structured populations pay little attention to the difference between fortuitous and deliberate processes leading to assortative grouping. Altruism may evolve when assortative grouping is fortuitously produced by forces external to the organism. But when it is deliberately produced by the same proximate mechanism that controls altruistic responses, as in humans, exploitation of altruists by selfish individuals is unlikely and altruism evolves as an individually advantageous trait. Groups formed with altruists (...) of this sort are special, because they are not affected by subversion from within. A synergistic process where altruism is selected both at the individual and at the group level can take place. (shrink)
Dual aspect theory has conceptual advantages over alternative mind-body notions, but difficulties of its own. The nature of the underlying psychophysical ground, for one, remains problematic either in terms of the principle of complementarity or if mind and matter are taken to be aspects of something like energy, movement, or information. Moreover, for a dual aspect theory to be plausible it should avoid the four perils of all mind-body theories: epiphenomenalism, reductionism, gross panpsychism, and the problems of emergence. An alternative (...) dual aspect theory, patterned process theory, is introduced and defended in neurological and individuality terms. The concept is grounded in a brain model of hierarchies wherein consciousness is conceived to be a cognitive aspect of the highest emergent brain inter-module activity, which is situated in the context of a living organism coping with a changing environment. The notion of individuals as psychophysical units unfolding as patterned processes is shown to constitute an integrative approach to brain, consciousness, and behavior that can avoid the conceptual perils and meet the ontological requirements of dual aspect reality and thereby advance the foundations of an integrative mind-body science. (shrink)
Economic theory has tended to reduce all social bonds and relations to forms of contract, whereas social theory has seen contracts as opposed to, and destructive of, genuine social bonds. Bruni sees these contrapositions as ideological (‘left’ against ‘right’, p. xi). His main goal is to overcome them; to show that three forms of reciprocity, covering the ideological spectrum from left to right, are complementary and simultaneously required in a healthy society. These three forms are, in his words: ‘(1) the (...) reciprocity of contract or ‘cautious’; (2) the reciprocity of friendship or philia and (3) the ‘unconditional’ reciprocity, the one more controversial . . .’ (p. x). (shrink)
Botanical preparations used by shamans in rituals for divination, prophecy, and ecstasy contain widely different psychoactive compounds, which are incorrectly classified under a single denomination such as “hallucinogens,” “psychedelics,” or “entheogens.” Based on extensive ethnopharmacological search, I proposed a psychopharmacological classification of magic plants in 1979. This paper re-evaluates this taxonomy in the context of consciousness research. Several groups of psychodysleptic magic plants are proposed: (1) hallucinogens—psilocybin mushrooms, mescaline cacti, dimethyltryptamine snuffs, and the synthetic ergoline lysergic acid diethylamide induce strong (...) perceptual changes, affective intensification, and cognitive enhancement. Their ethnobotanical uses include long lasting divination rituals, prophecy, and sacramental practice. (2) Trance-inducers—ergoline Convolvulaceae and South American Banisteriopsis produce quietness, abstraction, lethargy, mild sensorial and cognitive changes, and salient visual imagery changes used in trance rituals and specific divination practices. (3) Cognodysleptics—marijuana (tetrahydrocannabinol) and other terpene-containing plants induce changes in thought, imagination, and affective functions and are used in short-term divination or oneiromancy. (4) Deliriants—tropane-containing Solanaceae, wild tobacco, and Amanita muscaria (muscimol) induce a delirium characterized by dim and clouded consciousness, stupor, confusion, disorientation, perception distortion, difficulties in recollection, anxiety, irritability, excitation, and behavioral disorganization employed in sorcery, purification, or exorcism rituals. The core mental effects required for a drug to be used in shamanistic rituals include light-headedness, enhanced imagery, and experience intensification. This constellation was the reason why, in his classification of psychoactive compounds, the pioneer German psychopharmacologist Louis Lewin established in 1924 a group of drugs under the appropriate name of Phantastica. (shrink)
Recent developments in evolutionary game theory argue the superiority of punishment over reciprocity as accounts of large-scale human cooperation. I introduce a distinction between a behavioral and a psychological perspective on reciprocity and punishment to question this view. I examine a narrow and a wide version of a psychological mechanism for reciprocity and conclude that a narrow version is clearly distinguishable from punishment, but inadequate for humans; whereas a wide version is applicable to humans but indistinguishable from punishment. The mechanism (...) for reciprocity in humans emerges as a meta-norm that governs both retaliation and punishment. I make predictions open to empirical investigation to confirm or disconfirm this view. (shrink)
Altruism is a central concept in evolutionary biology. Evolutionary biologists still disagree about its meaning (E.O. Wilson 2005; Fletcher et al. 2006; D.S. Wilson 2008; Foster et al. 2006a, b; West et al. 2007a, 2008). Semantic disagreement appears to be quite robust and not easily overcome by attempts at clarification, suggesting that substantive conceptual issues lurk in the background. Briefly, group selection theorists define altruism as any trait that makes altruists losers to selfish traits within groups, and makes groups of (...) altruists fitter than groups of non-altruists. Inclusive fitness theorists reject a definition based on within- and between-group fitness. Traits are altruistic only if they cause a direct and absolute fitness loss to the donor. The latter definition is more restrictive and rejects as cases of altruism behaviors that are accepted by the former. Fletcher and Doebeli (2009) recently proposed a simple, direct and individually based fitness approach, which they claim returns to first principles: carriers of the genotype of interest “must, on average, end up with more net direct fitness benefits than average population members.” This seductively simple proposal uses the concept of assortment to explain how diverse kinds of altruists end up on average with more net fitness than their non-altruistic rivals. In this paper I shall argue that their approach implies a new concept of altruism that contrasts with and improves on the concept of the inclusive fitness approach. (shrink)
The syllogism and the predicate calculus cannot account for an ontological argument in Descartes' Fifth Meditation and related texts. Descartes' notion of god relies on the analytic-synthetic distinction, which Descartes had identified before Leibniz and Kant did. I describe how the syllogism and the predicate calculus cannot explain Descartes' ontological argument; then I apply the analytic-synthetic distinction to Descartes’ idea of god.
Is morality biologically altruistic? Does it imply a disadvantage in the struggle for existence? A positive answer puts morality at odds with natural selection, unless natural selection operates at the level of groups. In this case, a trait that is good for groups though bad (reproductively) for individuals can evolve. Sociobiologists reject group selection and have adopted one of two horns of a dilemma. Either morality is based on an egoistic calculus, compatible with natural selection; or morality continues tied to (...) psychological and biological altruism but not as a product of natural selection. The dilemma denies a third possibility—that psychological altruism evolves as a biologically selfish trait. I discuss the classical treatments of the paradox by Charles Darwin ([1871] 1989) and Robert Trivers (1971), focusing on the role they attribute to social emotions. The upshot is that both Darwin and Trivers sketch a natural-selection process relying on innate emotional mechanisms that render morality adaptive for individuals as well as for groups. I give additional reasons for viewing it as a form of natural, instead of only cultural, selection. (shrink)
Los sociobiólogos han defendido una posición "calvinista" que se resume en la siguiente fórmula: si la selección natural explica las actitudes morales, no hay altruismo genuino en la moral; si la moral es altruista, entonces la selección natural no puede explicarla. En este ensayo desenmascaro los presupuestos erróneos de esta posición y defiendo que el altruismo como equidad no es incompatible con la selección natural. Rechazo una concepción hobbesiana de la moral, pero sugiero su empleo en la interpretación de la (...) psicología de los primates no humanos y en un modelo de progresión evolutiva que habría llevado a la moralidad como adaptación pasando por la razón instrumental. /// Sociobiologists have endorsed a "Calvinist" position captured in the following formula: if natural selection explains moral attitudes, morality is not genuinely altruistic; if morality is altruistic, then natural selection cannot explain it. I expose the false presuppositions behind this claim and argüe that altruism as fairness is not incompatible with natural selection. I reject a Hobbesian view of morality as an instrumental endorsement of fairness norms, but suggest its use to interpret primate psychology and to model an evolutionary progression ending in moral capacities as adaptations. (shrink)
Classical evolutionary explanations of social behavior classify behaviors from their effects, not from their underlying mechanisms. Here lies a potential objection against the view that morality can be explained by such models, e.g. Trivers’reciprocal altruism. However, evolutionary theory reveals a growing interest in the evolution of psychological mechanisms and factors them in as selective forces. This opens up perspectives for evolutionary approaches to problems that have traditionally worried moral philosophers. Once the ability to mind-read is factored-in among the relevant variables (...) in the evolution of moral abilities and counted among the selection pressures that have plausibly shaped our nature as moral agents, an evolutionary approach can contribute, so I will argue, to the solution of a long-standing debate in moral philosophy and psychology concerning the basic motivation for moral behavior. (shrink)
There has been relatively little empirical research into the causes of research misconduct. To begin to address this void, the authors collected data from closed case files of the Office of Research Integrity (ORI). These data were in the form of statements extracted from ORI file documents including transcripts, investigative reports, witness statements, and correspondence. Researchers assigned these statements to 44 different concepts. These concepts were then analyzed using multidimensional scaling and cluster analysis. The authors chose a solution consisting of (...) seven clusters: (1) personal and professional stressors, (2) organizational climate, (3) job insecurities, (4) rationalizations A, (5) personal inhibitions, (6) rationalizations B and, (7) personality factors. The authors discuss the implications of their findings for policy and for future research. (shrink)
Burning fossil fuel in the North American continent contributes more to the CO2 global warming problem than in any other continent. The resulting climate changes are expected to alter food production. The overall changes in temperature, moisture, carbon dioxide, insect pests, plant pathogens, and weeds associated with global warming are projected to reduce food production in North America. However, in Africa, the projected slight rise in rainfall is encouraging, especially since Africa already suffers from severe shortages of rainfall. For all (...) regions, a reduction in fossil fuel burning is vital. Adoption of sound ecological resource management, especially soil and water conservation and the prevention of deforestation, is important. Together, these steps will benefit agriculture, the environment, farmers, and society as a whole. (shrink)
Scientific-technological innovation (particularly in the field of transgenic foods and cloning), scientific journalism and public opinion all share a complex relationship. The rupture of internal consensus among the scientific community, the role played by scientific journalists as "mediators" and the differentiation between what can be referred to as the "informed public" or "epistemological leaders" and the rest of the population were the starting point for our research on the impact of news related to biotechnological advances. In this paper we will (...) show the principal characteristics of the discourse on this type of news among what we can call the "informed public". From there, we will establish a set of strategies for improving the level of scientific-technological alphabetisation in our complex societies. (shrink)
The current ethical structure for collaborative international health research stems largely from developed countries' standards of proper ethical practices. The result is that ethical committees in developing countries are required to adhere to standards that might impose practices that conflict with local culture and unintended interpretations of ethics, treatments, and research. This paper presents a case example of a joint international research project that successfully established inclusive ethical review processes as well as other groundwork and components necessary for the (...) conduct of human behavior research and research capacity building in the host country. (shrink)
Individual and group selection are usually conceived as opposed evolutionary processes. Though cases of synergy are occasionally recognized, the evolutionary importance of synergy is largely ignored. However, synergy is the plausible explanation for the evolution of collectives as higher level individuals i.e., collectives acting as adaptive units, e.g., genomes and colonies of social insects. It rests on the suppression of the predictable tendency of evolutionary units to benefit at the expense of other units or of the wholes they contribute to (...) build. It plausibly explains human cooperation and morality: the molding of human groups into adaptive units. (shrink)
The architecture of brain, consciousness, and behavioral processes is shown to be formally similar in that all three may be conceived and depicted as Petri net patterned processes structured by a series of elements occurring or becoming active in stochastic succession, in parallel, with different rhythms of temporal iteration, and with a distinct qualitative manifestation in the spatiotemporal domain. A patterned process theory is derived from the isomorphic features of the models and contrasted with connectionist, dynamic system notions. This empirically (...) derived formulation is considered to be optimally compatible with the dual aspect theory in that the foundation of the diverse aspects would be a highly structured and dynamic process, the psychophysical neutral “ground” of mind and matter posed (but not properly determined) by dual aspect and neutral monist theories. It is methodologically sound to approach each one of these processes with specific tools and to establish concurrences in real time between them at the organismic level of analysis. Such intra-level and inter-perspective correlations could eventually constitute psychophysical bridge-laws. A mature psychology of consciousness is necessary to situate and verify the bridges required by a genuine mind-body science. (shrink)
Drawing on the work of John Rawls and Thomas Pogge, I argue that the U.S. is in part responsible for the immigration of Mexicans and Central Americans into the U.S. By seeking to further its national interests through its foreign policies, the U.S. has created economic and politically oppressive conditions that Mexican and Central American people seek to escape. The significance of this project is to highlight the role of the U.S. in illegal immigration so that we may first acknowledge (...) our responsibility in order to seek lasting humane solutions. (shrink)
The subject of this paper is the new theory of political liberalism, developed by people like jJohn Rawls and Charles Larmore. This is a quite specific subject and it should not be confused with another and more usual meaning attached to the same expression. This more conventional meaning of political liberalism is primarily a form of liberalism which stresses the political sphere - the state - as opposed to the economic sphere - the marketplace. However, the new theory of political (...) liberalism is not in opposition to economic liberalism in this way. Instead, the adjective political refers to the fact that this recent defence of liberalism avoids reliance on comprehensive and controversial religious, metaphysical, epistemological, and moral views. In this sense, political liberalism is a theory of argumentative restraint regarding the defence of liberal justice. (shrink)
This essay represents a critical reading, appreciation and assessment of responses written by Susan Abraham, Conrad T. Gromada, and Michael Barnes to my book On Being Human: U.S Hispanic and Rahnerian Perspectives (Orbis Books, 2001). The essay addresses the following three themes: 1) Rahner’s Ignatian heritage and its relation to the U.S. Hispanic appropriation of the preferential option for the poor and marginalized, 2) Rahner’s understanding of one mediator and many human mediations, and 3) Rahner’s transcendental theological approach in relation (...) to the experience of contemporary manifestations of atheism in the U.S. These themes highlight aspects of my book that Abraham, Gromada, and Barnes found fertile ground for engaging in theological conversation. First, with respect to Rahner’s Ignatian spirituality, I argue that the Ignatian understanding of indiferencia can be correlated with the preferential option for the poor and marginalized. Second, with respect to Rahner’s understanding of one mediator and many mediations, I explore other ways in which my book could contextualize Rahner’s approach. Finally, I underscore the historical moment in Rahner’s transcendental theological approach (the mystery of God encountered in, with, and under historical realities) and point to a contemporary implication of this understanding (e.g., practical atheism). (shrink)
Background Non-therapeutic trials in which terminally ill cancer patients are asked to undergo procedures such as biopsies or venipunctures for research purposes, have become increasingly important to learn more about how cancer cells work and to realize the full potential of clinical research. Considering that implementing non-therapeutic studies is not likely to result in direct benefits for the patient, some authors are concerned that involving patients in such research may be exploitive of vulnerable patients and should not occur at all, (...) or should be greatly restricted, while some proponents doubt whether such restrictions are appropriate. Our objective was to explore clinician-researcher attitudes and concerns when recruiting patients who are in advanced stages of cancer into non-therapeutic research. Methods We conducted a qualitative exploratory study by carrying out open-ended interviews with health professionals, including physicians, research nurses, and study coordinators. Interviews were audio-recorded and transcribed. Analysis was carried out using grounded theory. Results The analysis of the interviews unveiled three prominent themes: 1) ethical considerations; 2) patient-centered issues; 3) health professional issues. Respondents identified ethical issues surrounding autonomy, respect for persons, beneficence, non-maleficence, discrimination, and confidentiality; bringing to light that patients contribute to science because of a sense of altruism and that they want reassurance before consenting. Several patient-centered and health professional issues are having an impact on the recruitment of patients for non-therapeutic research. Facilitators were most commonly associated with patient-centered issues enhancing communication, whereas barriers in non-therapeutic research were most often professionally based, including the doctor-patient relationship, time constraints, and a lack of education and training in research. Conclusions This paper aims to contribute to debates on the overall challenges of recruiting patients to non-therapeutic research. This exploratory study identified general awareness of key ethical issues, as well as key facilitators and barriers to the recruitment of patients to non-therapeutic studies. Due to the important role played by clinicians and clinician-researchers in the recruitment of patients, it is essential to facilitate a greater understanding of the challenges faced; to promote effective communication; and to encourage educational research training programs. (shrink)
La experiencia de musulmanes, judíos y cristianos ante el sufrimiento, la muerte y la enfermedad tiene muchos puntos en común que es necesario y urgente resaltar. El libro está dividido entres partes que corresponden a las tres tradiciones analizadas. Consta de treinta artículos escritos por veintisiete autores. Participan profesores no sólo de las Universidades de Comillas, Deusto y Granada sino del Instituto Bíblico de Roma, de la Universidad Gregoriana de Roma, de la Universidad de Munich, de la Universidad Complutense de (...) Madrid, del Seminario Evangélico Unido de Teología (SEUT) y de la Facultad de Teología de Catalunya. Colaboran, por supuesto, sacerdotes católicos, pastores protestantes, un rabino y el secretario del Consejo Europeo de Mezquitas. Sin duda, nos encontramos ante una gran aportación en el campo de la Bioética y en la reflexión en torno al dolor, la enfermedad y la muerte. (shrink)
It is discussed in this paper on the existence and the consistency of a concept of human nature in Nietzsche’s work that would not relapse into the extreme readings neither of the biologicism nor of the historicism. For it it’s carried out an interpretation that joins Nietzsche’s consideration of the nature and the history about the matrix concept of the ahistorical, which will lead the initial reflection on the culture to an analysis in ontological-formal terms of the man’s nature and (...) his anchorage in the nature of the world. (shrink)
La Bioética es una joven disciplina con apenas tres décadas de recorrido en nuestro país. Durante todo este tiempo, la Cátedra de Bioética de la Universidad Pontificia Comillas ha contribuido activamente a la reflexión, diálogo y divulgación de la Bioética. Este año, ha querido celebrar su XXV Seminario Interdiciplinar reuniendo a las principales instituciones y autores que han sido y son referentes ineludibles en esta reflexión bioética. Este libro recoge la mirada histórica del mucho y buen trabajo realizado en todo (...) este tiempo, la situación actual de esta disciplina que intenta servir a una sociedad en continuo cambio y las perspectivas de futuro que se plantean las principales instituciones que hoy por hoy dan forma a la Bioética española. (shrink)
Abstract The architecture of brain, consciousness, and behavioral processes is shown to be formally similar in that all three may be conceived and depicted as Petri net patterned processes structured by a series of elements occurring or becoming active in stochastic succession, in parallel, with different rhythms of temporal iteration, and with a distinct qualitative manifestation in the spatiotemporal domain. A patterned process theory is derived from the isomorphic features of the models and contrasted with connectionist, dynamic system notions. This (...) empirically derived formulation is considered to be optimally compatible with the dual aspect theory in that the foundation of the diverse aspects would be a highly structured and dynamic process, the psychophysical neutral ?ground? of mind and matter posed (but not properly determined) by dual aspect and neutral monist theories. It is methodologically sound to approach each one of these processes with specific tools and to establish concurrences in real time between them at the organismic level of analysis. Such intra?level and inter?perspective correlations could eventually constitute psychophysical bridge?laws. A mature psychology of consciousness is necessary to situate and verify the bridges required by a genuine mind?body science. (shrink)
In this paper I submit that, if one takes seriously the distinction between citizenship rights and human rights, the list of the latter must be minimized. Many of the rights that we are used to call human rights are, in fact, citizenship rights and they belong to a history of citizenship in some specific states around the world. Thelist of human rights must be much shorter than the list of citizenship rights, whatever that list may be in accordance with the (...) grounds attributed to human rights by different philosophical approaches. My plea for a qualification of which rights should count as human rights and the idea of a short list challenges the consensus among international lawyers. Nevertheless, it does not aim at a critique of human rights as such. On the contrary, the general intention of the very idea of a short list is to strengthen the moral force of human rights in order to make them meaningful in different political contexts. (shrink)
La celebración de fiestas en honor a los santos patronos de las comunidades andinas es una de las manifestaciones de religiosidad más extendidas desde Colonia. Másallá de entenderla como una manifestación en continuidad directa con las prácticas cúlticas del Tawantinsuyo o la ritualidad católica española, consideramos que esta festividad es un fenómeno emergente que debe ser analizado en su especificidad. El objetivo de este artículo es analizar la figura del santo y su eficacia simbólico-ritual en la fiesta patronal andina desarrollada (...) durante el periodo colonial (XVI-XVII). A partir del análisis de una serie de crónicas coloniales, intentaremos mostrar que las especificidades rituales de la fiesta y de la operación del santo como símbolo icónico dominante permiten comprender su eficacia simbólica, así como también la co-existencia de diversas interpretaciones y escenificaciones rituales que darían cuenta de la agencialidad ritual de la comunidad. The celebration of festivities in honor of the patron saints of the Andean communities is one of the most widespread manifestations of religiosity from the Colony. Beyond understood as a manifestation in direct continuity with the cultic practices of the Catholic ritual Tawantinsuyo or Spanish, we believe that this festival is an emerging phenomenon that must be analyzed in its specificity. The aim of this paper is to analyze the figure of the saint and their efficacy in symbolic ritual Andean fiesta developed during the colonial period (XVI-XVII). From the analysis of a series of colonial chronicles, try to show that the specific rituals of celebration and operation saint as provide insight dominant iconic symbol symbolic effectiveness, as well as the co-existence of different interpretations and stagings rituals give account of agency community ritual. (shrink)
Miguel Díaz has succeeded quite well not only in providing support for popular Hispanic religion through an analysis of ideas from Karl Rahner, but skillfully meets several possible objections or alternatives. Nonetheless, the more sophisticated forms of Hispanic theology must also be sustained, if only to address adequately the transcendental atheism that the current and subsequent generation of Latino/a college students will encounter.
In the context of acknowledging the contrast between Marian devotional life and eucharistic theology, this response to Díaz’s book makes several connections between the two, including a glimpse into Rahner’s own devotional piety. While affirming and approving the overall content of this study by Díaz, the respondent uses a more recent article by Rahner to suggest four topics that might have enhanced the book: 1) how Marian devotion is founded on the doctrine of the communion of the saints; 2) how (...) Mary’s unimportance and marginalized position enhanced her unique acceptance of grace for the sake of all humanity; 3) how Rahner’s emphasis on women’s equality can figure in the present theological conversation about the relevance of Jesus’ maleness; and 4) how there is room inthe church for a variety of individual and cultural approaches to the theology of grace and to the devotional life of the faithful. (shrink)
The philosophical tradition of liberal political thought has come to see tolerance as a crucial element of a liberal political order. However, while much has been made of the value of toleration, little work has been done on individual-level motivations for tolerant behavior. In this article, we seek to develop an account of the rational motivations for toleration and of where the limits of toleration lie. We first present a very simple model of rational motivations for toleration. Key to this (...) model is an application of David Ricardo’s model of trade to thinking about toleration. This model supports the claim that we always have reasons to be as tolerant as possible. We then explore why we do not always see tolerant attitudes in the actual world, and point to some potential preconditions for toleration that the initial model does not capture. Subsequently, we examine a more detailed model that allows us to investigate more carefully the conditions under which tolerant behavior can be rewarded. We conclude by arguing that a consideration of self-interested motivations for toleration is essential to the success of a robust theory of toleration for a diverse society, but that even this approach has its limitations. (shrink)
The debates over the future of human population and the earth’s environment, and similar large issues, usually take place without reference to explicit models. Debate would be clarified if such models were employed. We propose that the logistic equation and its extensions like the generalized logistic and the Lotka-Volterra equations, so familiar to ecologists, can easily be modified to model the important "macro" questions that motivated the three thinkers of our title. The long term rate of population growth must normally (...) be controlled by the rate of improvement in K, the carrying capacity of the earth. K will in turn be controlled by the rate of technological progress. The present situation, in which technological improvement (but also perhaps environmental deterioration) are increasing at rates above r, the Malthusian intrinsic rate of natural increase, is probably unique in human history. Can present levels of human prosperity and population growth be sustained? What processes are most likely to determine the answer to this and similar questions? We here sketch a model that endogenizes technological progress and environmental deterioration in the logistic framework. We discuss extensions of the logistic approach to multiple populations, such as other species, and sub-populations, such as human social classes, using the Lotka-Volterra equations. (shrink)
