Sociability, Luxury and Sympathy: The Case of Archibald Campbell

The eighteenth-century moral philosopher Archibald Campbell is now largely forgotten, even to specialists in the Scottish Enlightenment. Yet his work is worth recovering both as part of the immediate reception of Bernard Mandeville and Francis Hutcheson's rival moral philosophies, and for better understanding the state of Scottish moral philosophy a decade before David Hume published his Treatise of Human Nature. This paper offers a reading of Campbell as deploying a specifically Epicurean philosophy that resists both the Augustinianism of Mandeville, and the Stoicism of Hutcheson. This leads him onto ground later claimed more conclusively by Hume, whilst helping us to better conceptualise the deployment and recovery of Hellenistic thought in the early modern period.This is the accepted manuscript. The final version is available at http://www.tandfonline.com/doi/abs/10.1080/01916599.2012.747255

Smith and Rousseau, after Hume and Mandeville

This is the author accepted manuscript. The final version is available from SAGE via https://doi.org/10.1177/0090591716656459 This essay re-examines Adam Smith’s encounter with Jean-Jacques Rousseau. Against the grain of present scholarship it contends that when Smith read and reviewed Rousseau’s Second Discourse, he neither registered it as a particularly important challenge, nor was especially influenced by, or subsequently preoccupied with responding to, Rousseau. The case for this is made by examining the British context of Smith’s own intervention in his 1759 Theory of Moral Sentiments, where a proper appreciation of the roles of David Hume and Bernard Mandeville in the formation of Smith’s thought pushes Rousseau firmly into the background. Realising this, however, forces us to re-consider our evaluations of Rousseau’s and Smith’s very different political visions. Given that questions of individual recognition, economic inequality, and political stability remain at the heart of today’s social challenges, the implications of this are not just historical but of direct contemporary import. </jats:p

THE STATE WITHOUT SOVEREIGNTY: AUTHORITY AND OBLIGATION IN HUME’S POLITICAL PHILOSOPHY.

Hume has no theory of sovereignty. As a result he is frequently supposed to lack a proper theory of politics, providing only a political sociology incapable of addressing the central normative significance of political obligation in thinking about the modern state. This is a serious mistake. Hume addressed himself directly to the question of political obligation, but his argument was predicated upon a prior reconfiguration of our thinking about the nature, role and power of philosophy. In coming to appreciate this prior reconfiguration, in particular via a re-examination of Hume’s indirect engagement with Locke’s earlier juridical political theory, we can properly appreciate Hume as advancing a radically innovative theory of political obligation. What emerges is the possibility of a theory of the state without sovereignty. As well as thereby revealing Hume to be a major and highly original post-Hobbesian theorist of the state, we are invited to consider whether present political theory would do better by adopting Hume’s recommended philosophical reconceptualization. [ABSTRACT FROM AUTHOR]Research was undertaken with support from the Arts and Humanities Research Council, and the University of Cambridge Prince Consort and Thirlwall priz

A study of the long term evolution of quasi periodic oscillations in the accretion powered X-ray pulsar 4U 1626-67

We report here a study of the long term properties of Quasi Periodic Oscillations (QPO) in an unusual accreting X-ray pulsar, 4U 1626--67. This is a unique accretion powered X-ray pulsar in which we have found the QPOs to be present during all sufficiently long X-ray observations with a wide range of X-ray observatories. In the present spin-down era of this source, the QPO central frequency is found to be decreasing. In the earlier spin-up era of this source, there are only two reports of QPO detections, in 1983 with EXOSAT and 1988 with GINGA with an increasing trend. The QPO frequency evolution in 4U 1626--67 during the last 22 years changed from a positive to a negative trend, somewhat coincident with the torque reversal in this source. In the accretion powered X-ray pulsars, the QPO frequency is directly related to the inner radius of the accretion disk, as per Keplerian Frequency Model (KFM) and Beat Frequency Model (BFM). A gradual depletion of accretion disk is reported earlier from the X-ray spectral, flux and pulse profile measurements. The present QPO frequency evolution study shows that X-ray flux and mass accretion rate may not change by the same factor, hence the simple KFM and BFM are not able to explain the QPO evolution in this source. This is the only X-ray pulsar to show persistent QPOs and is also the first accreting X-ray pulsar in which the QPO history is reported for a long time scale relating it with the long term evolution of the accretion disk.Comment: 14 pages, 3 figures. Accepted for publication in Ap

Clear Evidence for Intranight Optical Variability in Radio-quiet Quasars

We present new clues to the problem of the radio loudness dichotomy arising from an extensive search for intranight optical variability in seven sets of optically luminous radio-quiet quasars and (radio-loud) BL Lacertae objects, which are matched in optical luminosity and redshift. Our monitoring of radio-quiet quasars has for the first time clearly detected such intranight variability, with peak-to-peak amplitudes ~1%, occurring with a duty cycle of ~ 1/6. The matched BL Lacs have both higher variability amplitudes and duty cycles when observed in the same fashion. We show that the much less pronounced intranight variability of the radio-quiet quasars relative to BL Lacs can be understood in terms of a modest misalignment of the jets in radio-quiet quasars from the line-of-sight. We thus infer that relativistic particle jets may well also emerge from radio-quiet quasars, but while traversing the short optical-emitting distances, they could be snuffed out, possibly through inverse Compton losses in the nuclear region.Comment: 13 pages, 3 figures, in press in ApJ Letters (20 March 2003

Improved characterisation of intra-night optical variability of prominent AGN classes

The incidence of intra-night optical variability (INOV) is known to to differ significantly among different classes of powerful active galactic nuclei (AGN). A number of statistical methods have been employed in the literature for testing the presence of INOV in the light curves, sometimes leading to discordant results. In this paper we compare the INOV characteristics of six prominent classes of AGN, as evaluated using three commonly used statistical tests, namely the $\chi^2-$test, the modified $C-$test and the $F-$test, which has recently begun to gain popularity. The AGN classes considered are: radio-quiet quasars (RQQs), radio-intermediate quasars (RIQs), lobe-dominated quasars (LDQs), low optical polarization core-dominated quasars (LPCDQs), high optical polarization core-dominated quasars (HPCDQs), and TeV blazars. Our analysis is based on a large body of AGN monitoring data, involving 262 sessions of intra-night monitoring of a total 77 AGN, using 1-2 metre class optical telescopes located in India. In order to compare the usefulness of the statistical tests, we have also subjected them to a `sanity check' by comparing the number of false positives yielded by each test with the corresponding statistical prediction. The present analysis is intended to serve as a benchmark for future INOV studies of AGN of different classes.Comment: 26 pages, 2 tables, Accepted for publication in MNRA

On the photometric error calibration for the `differential light curves' of point-like Active Galactic Nuclei

It is important to quantify the underestimation of rms photometric errors returned by the commonly used \emph APPHOT algorithm in the \emph IRAF software, in the context of differential photometry of point-like AGN, because of the crucial role it plays in evaluating their variability properties. Published values of the underestimation factor, $\eta$, using several different telescopes, lie in the range 1.3 - 1.75. The present study aims to revisit this question by employing an exceptionally large data set of 262 differential light curves (DLCs) derived from 262 pairs of non-varying stars monitored under our ARIES AGN monitoring program for characterizing the intra-night optical variability (INOV) of prominent AGN classes. The bulk of these data were taken with the 1-m Sampurnanad Telescope (ST). We find $\eta$ = 1.54$\pm$0.05 which is close to our recently reported value of $\eta$ = 1.5. Moreover, this consistency holds at least up to a brightness mismatch of 1.5 mag between the paired stars. From this we infer that a magnitude difference of at least up to 1.5 mag between a point-like AGN and comparison star(s) monitored simultaneously is within the same CCD chip acceptable, as it should not lead to spurious claims of INOV.Comment: 20 pages, 3 figures and 1 table; accepted for publication in JAp

Intra-night Optical Variability of BL Lacs, Radio-Quiet Quasars and Radio-Loud Quasars

We report optical monitoring observations of 20 high-luminosity AGN, 12 of which are radio-quiet quasars (RQQs). Intra-night optical variability (INOV) was detected for 13 of the 20 objects, including 5 RQQs. The variations are distinctly stronger and more frequent for blazars than for the other AGN classes. By combining these data with results obtained earlier in our program, we have formed an enlarged sample consisting of 9 BL Lacs, 19 RQQs and 11 lobe-dominated radio-loud quasars. The moderate level of rapid optical variability found for both RQQs and radio lobe-dominated quasars argues against a direct link between INOV and radio-loudness. We supplemented the present observations of 3 BL Lacs with additional data from the literature. In this extended sample of 12 well observed BL Lacs, stronger INOV is found for the EGRET detected BL Lacs.Comment: 8 pages, 3 Postscript figures, Accepted for publication in MNRAS, uses mn2e.cl