One commendable aspect of the ruminations by H.L.A Hart on legal positivism, which quite a few contemporary philosophers of law have not fully absorbed, is that he recognised the diversity of the points of contention that have pitted the devotees of positivism against the devotees of natural-law theories. Whereas some present-day philosophers of law are inclined to refer to “the separability thesis” of legal positivism – with the definite article “the” as a signal that there is one defining point of dispute between legal positivists and their opponents – Hart knew that there is no single such thesis. Natural-law theorists have in fact postulated numerous connections between law and morality which putatively clinch the character of law as an inherently moral phenomenon, and legal positivists have posed challenges to each of those connections or to the claim that any unchallenged connection serves to establish the inherently moral character of law.

This paper first recapitulates the objections by H.L.A. Hart to the ways in which John Austin’s command model of law obfuscated the importance and the very existence of power-conferring laws. Although those objections are familiar in the world of contemporary legal philosophy, their insightfulness is highlighted here because they contrast so sharply with Hart’s own neglect of power-conferring laws at some key junctures in his theorizing. In the second half of this paper, I ponder a few of the junctures where Hart failed to heed the admonitions which he had so deftly leveled against Austin.

We describe an ultra-wide-bandwidth, low-frequency receiver recently installed on the Parkes radio telescope. The receiver system provides continuous frequency coverage from 704 to 4032 MHz. For much of the band (${\sim}60\%$), the system temperature is approximately 22 K and the receiver system remains in a linear regime even in the presence of strong mobile phone transmissions. We discuss the scientific and technical aspects of the new receiver, including its astronomical objectives, as well as the feed, receiver, digitiser, and signal processor design. We describe the pipeline routines that form the archive-ready data products and how those data files can be accessed from the archives. The system performance is quantified, including the system noise and linearity, beam shape, antenna efficiency, polarisation calibration, and timing stability.

Crop yields can be similar in organic and conventional systems even when weed biomass is greater in organic systems. Greater weed tolerance in organic systems may be due to differences in management-driven soil fertility properties. The goal of this experiment was to determine whether soil collected from a long-term organic cropping system with a diverse crop rotation and organic fertility inputs would support higher soil nitrogen (N) resource partitioning, as indicated by overyielding of corn–weed mixtures, than a cropping system with a less diverse crop rotation and inorganic N inputs. A replacement series greenhouse experiment was conducted using corn : smooth pigweed and corn : giant foxtail proportions of 0 : 1, 0.25 : 0.75, 0.5 : 0.5, 0.75 : 0.25, and 1 : 0 and harvested at 29, 40, or 48 d after experiment initiation (DAI). The monoculture density of corn was 4 plants pot−1 and the monoculture density of each weed species was 36 plants pot−1. Corn was consistently more competitive than both weed species at 40 and 48 DAI when soil inorganic N was limiting to growth. Corn–smooth pigweed mixtures had greater shoot biomass and shoot N content than expected based on the shoot biomass and shoot N content of monocultures (i.e., overyielding) at the onset of soil inorganic N limitation, providing some evidence for N resource partitioning. However, soil management effects on overyielding were infrequent and inconsistent among harvest dates and corn–weed mixtures, leading us to conclude that management-driven soil fertility properties did not affect corn–weed N resource partitioning during the early stages of corn growth.

If there is one doctrine distinctively associated with legal positivism, it is the separability of law and morality. Both in opposition to classical natural-law thinkers and in response to more recent theorists such as Ronald Dworkin and Lon Fuller, positivists have endeavored to impugn any number of ostensibly necessary connections between the legal domain and the moral domain. Such is the prevailing view of legal positivism among people familiar with jurisprudence. During the past couple of decades, however, that prevailing view has come into question among some estimable legal positivists. In particular, Joseph Raz and his followers have queried the importance and the very tenability of an insistence on the separability of law and morality. The present article maintains that the traditional view of legal positivism is correct and that the recent skepticism about it on the part of some positivists is unfounded. When the notion of the disjoinability of law and morality is understood properly as a large array of theses, it proves to be resistant to the challenges that have been mounted against it.

In the course of evolving an extensive theory of natural law, John Finnis declares that certain goods are self-evident. Among these basic values, the good of knowledge lends itself to a special argument—an argument directed against people who assail the ranking of knowledge as a good. Finnis maintains that anyone who seriously denies the goodness of truth or knowledge must contradict herself flagrantly in the act of putting forth her position. Skeptics therefore exclude themselves from participating genuinely in a debate over truth’s value. Although their self-disqualification never tout seul establishes the goodness of knowledge, it “should persuade the sceptic[s] to cut short idle doubting” (NLNR at 75; see also “Scepticism” at 267). Or so Finnis believes.

In Law’s Empire, Ronald Dworkin combines his role as a legal theorist with his role as a political theorist. He sets forth a view of jurisprudence and law as modes or fields of interpretation, and he likewise propounds the notion that our current law can best be interpreted as a system pointing to the ideal of equality-of-resources. Nowhere does Dworkin’s combination of views emerge more piquantly than within his chapter entitled “The Common Law.” There Dworkin grants that much of English and American common law has had the effect of simulating markets—in other words, the effect of allocating productive forces in ways that would have come about via costless bargains among all relevant people. But he disputes the added thesis that the judicial simulation should be interpreted as the maximizing of wealth. Pitting himself against the economic approach to legal matters, Dworkin holds that we can best understand market-simulation as the achievement or pursuit of equality.

This essay maintains that the question in its title is really three sets of questions: a conceptual inquiry, a moral/political inquiry, and an empirical inquiry. After devoting some attention to the relevant conceptual issues, the essay ponders in detail the moral/political issues. It suggests some answers to the germane moral/political questions, and it takes pains to distinguish those questions from other lines of inquiry with which they might be confused. Although only animals and dead people are mentioned in the title, the essay also considers whether infants, comatose people, lunatics, future generations, groups, trees, and natural phenomena such as rivers should be classified as potential holders of legal rights.

Analyses of the social contract described by Thomas Hobbes have proceeded in three major directions. First, some readers naturally have felt that Hobbes viewed the primal charter as a genuine outcome of events which truly occurred. Other exegetes have contended that the story of the formation of the social contract was a deliberate fiction—either an artful narrative designed to elicit orderliness, or a heuristic model designed to spark hypothetical reasoning about what would have occurred in a primeval context with specified conditions. Still other analysts affirm that Hobbes used the tale of the social contract as a warning against the evils that plague a society which descends into civil strife.

In what follows, we must position ourselves in an obscure passage, a passage from the hostilities of nature to the serenity of civilized life. It is precisely here, at the dawn of social existence, that David Hume located the beginnings of law. His search for origins would eventuate in a narrative describing the spread of public peace by way of the greatest obstacle to such peace: unslacking self-interest. (That is what some refer to as an economy of means.) Along the route, language entered into his story with such prominence that it cannot safely be disregarded. We shall have to read Hume’s narrative as a narrative – that is, as a textual framing – if we hope to do justice to its arguments (about justice). To cross the gap between nature and society, we shall have to discover that the gap does not lie simply between them, but also lies within each of them. More specifically, we shall have to find that nature is perforce hollowed out by culture.

No one familiar with Ronald Dworkin’s work can fail to be aware of his view that jurisprudence and law are both fundamentally enterprises of moral justification. Throughout his writings, Dworkin has resolutely set himself against the legal-positivist insistence on the separability of law and morality. The present essay critically explores the arguments and assumptions that underlie his stance.

In Legality Scott Shapiro seeks to provide the motivation for the development of his own elaborate account of law by undertaking a critique of H.L.A. Hart's jurisprudential theory. Hart maintained that every legal system is underlain by a rule of recognition through which officials of the system identify the norms that belong to the system as laws. Shapiro argues that Hart's remarks on the rule of recognition are confused and that his model of law—though commendably more sophisticated than any model propounded by earlier legal positivists—is consequently untenable. Shapiro contends that a new approach is vital for progress in the philosophy of law and, with his lengthy presentation of his own Planning Theory of Law, he aspires to pioneer just such an approach. Except for a very terse observation in the final main section, this article does not directly assess the strengths and shortcomings of Shapiro's piquant planning theory. Instead, I defend Hart against Shapiro's charges and thereby undermine the motivation for the development of the planning theory.

The discovery of a pulsar or pulsars orbiting near the Galactic Center (GC) could offer an unprecedented probe of strong-field gravity, the properties of our galaxy's supermassive black hole and insights into the paradoxical star formation history of the region. However, searching for pulsars near the GC is severely hampered by the large electron densities along our line of sight and the scattering-induced pulse broadening of the pulsar emission observed through it. As the broadened pulse length approaches the pulsar period, the periodicity in pulsar emission becomes nearly undetectable. Searches extended to higher frequencies, in an effort to reduce scattering, suffer from reduced intrinsic flux, higher system temperatures and increased atmospheric opacity. We are currently attempting to mitigate the challenges associated with searching for pulsars near the GC by employing new wide bandwidth receivers, upgraded IF distribution systems and novel digital spectrometers in a GC pulsar search campaign at the Green Bank Telescope in West Virginia, USA.

Our search will cover two frequency bands, from 12-15 GHz (Ku Band) and 18-26 GHz (K Band), during a total of approximately 30 hours of observations, with expected characteristic 10-sigma sensitivities between 5-10 micro-Jy. Our first observations are scheduled for mid-March 2012. Here we will present the status of our observations and initial results.

A growing number of schools have increasingly de-emphasized the importance of providing physical activity opportunities during the school day, despite emerging research that illustrates the deleterious relationship between low levels of aerobic fitness and neurocognition in children. Accordingly, a brief review of studies that link fitness-related differences in brain structure and brain function to cognitive abilities is provided herein. Overall, the extant literature suggests that childhood aerobic fitness is associated with higher levels of cognition and differences in regional brain structure and function. Indeed, it has recently been found that aerobic fitness level even predicts cognition over time. Given the paucity of work in this area, several avenues for future investigations are also highlighted. (JINS, 2011, 17, 975–985)