The Case Against Powers

Powers ontologies are currently enjoying a resurgence. This would be dispiriting news for the moderns; in their eyes, to imbue bodies with powers is to slide back into the scholastic slime from which they helped philosophy crawl. I focus on Descartes’s ‘little souls’ argument, which points to a genuine and, I think persisting, defect in powers theories. The problem is that an Aristotelian power is intrinsic to whatever has it. Once this move is accepted, it becomes very hard to see how humble matter could have such a thing. It is as if each empowered object were possessed of a little soul that directs it and governs its behavior. Instead of attempting to resurrect the Aristotelian power theory, contemporary philosophers would be best served by taking their inspiration from its early modern replacement, devised by John Locke and Robert Boyle. On this view, powers are internal relations, not monadic properties intrinsic to their bearers. This move at once drains away the mysterious directedness of Aristotelian powers and solves the contemporary version of the little souls argument, Neil Williams’s ‘problem of fit.

Leibniz on Sensation and the Limits of Reason

I argue that Leibniz’s doctrine of sensory representation is intended in part to close an explanatory gap in his philosophical system. Unlike the twentieth century explanatory gap, which stretches between neural states on one side and phenomenal character on the other, Leibniz’s gap lies between experiences of secondary qualities like color and taste and the objects that cause them. The problem is that the precise arrangement and distribution of such experiences can never be given a full explanation. In response, Leibniz appeals to representation. I argue that the sense in which Leibnizian sensations are representations is too weak to close his explanatory gap. In the end, he must appeal to the doctrine of the best possible world

Leges sive natura: Bacon, Spinoza, and a Forgotten Concept of Law

The way of laws is as much a defining feature of the modern period as the way of ideas; but the way of laws is hardly without its forks. Both before and after Descartes, there are philosophers using the concept to carve out a very different position from his, one that is entirely disconnected from God or God’s will. I argue that Francis Bacon and Baruch Spinoza treat laws as dispositions that derive from a thing’s nature. This reading upends the currently orthodox treatment of Spinoza’s laws as infinite modes, and calls for a re-conception of his metaphysics of causation

Locke and the Real Problem of Causation

Discussions of John Locke’s theory of causation tend, understandably, to focus on the related notion of power and in particular the dialectic with David Hume. But Locke faces a very different threat, one that is internal to his view. For he argues both that causation is a relation and that relations are not real. The obvious conclusion is intolerable. And yet the premises, I argue, are unassailable. Building on an interpretation of Locke’s treatment of relations I have developed elsewhere, I show how Locke can at once speak meaningfully of causation and deny its mind-independent existence

Probing Extreme-Density Matter with Gravitational Wave Observations of Binary Neutron Star Merger Remnants

We present a proof-of-concept study, based on numerical-relativity simulations, of how gravitational waves (GWs) from neutron star merger remnants can probe the nature of matter at extreme densities. Phase transitions and extra degrees of freedom can emerge at densities beyond those reached during the inspiral, and typically result in a softening of the equation of state (EOS). We show that such physical effects change the qualitative dynamics of the remnant evolution, but they are not identifiable as a signature in the GW frequency, with the exception of possible black-hole formation effects. The EOS softening is, instead, encoded in the GW luminosity and phase and is in principle detectable up to distances of the order of several Mpcs with advanced detectors and up to hundreds of Mpcs with third generation detectors. Probing extreme-density matter will require going beyond the current paradigm and developing a more holistic strategy for modeling and analyzing postmerger GW signals.Comment: 5 pages, 3 figures. Matches version accepted on ApJ

Modern Philosophy

1. Preface2. Minilogic and Glossary3. Background to Modern Philosophy4. Ren� Descartes (1596�1650)5. Baruch Spinoza (1632�1677)6. John Locke�s (1632�1704) Essay Concerning Human Understanding (1689)7. George Berkeley (1685�1753)8. David Hume�s (1711�1776) Enquiry Concerning Human Understanding9. Immanuel Kant (1724�1804)This is a textbook (or better, a workbook) in modern philosophy. It combines readings from primary sources with two pedagogical tools. Paragraphs in italics introduce figures and texts. Numbered study questions (also in italics) ask students to reconstruct an argument or position from the text, or draw connections among the readings. And I [ie. Alexander Dunn] have added an introductory chapter (Chapter 0 - Minilogic and Glossary), designed to present the basic tools of philosophy and sketch some principles and positions. The immediate goal is to encourage students to grapple with the ideas rather than passing their eyes over the texts. This makes for a better classroom experience and permits higher-level discussions

Connecting Gas Dynamics and Star Formation Histories in Nearby Galaxies: The VLA-ANGST Survey

In recent years, HST revolutionized the field of star formation in nearby galaxies. Due to its high angular resolution it has now become possible to construct star formation histories of individual stellar populations on scales of a few arcseconds spanning a range of up to ~600 Myr. This method will be applied to the ANGST galaxies, a large HST volume limited survey to map galaxies up to distances of 3.5-4.0 Mpc (excluding the Local Group). The ANGST sample is currently followed--up by high, ~6'' resolution VLA observations of neutral, atomic hydrogen (HI) in the context of VLA-ANGST, an approved Large VLA Project. The VLA resolution is well matched to that of the spatially resolved star formation history maps. The combination of ANGST and VLA-ANGST data will provide a new, promising approach to study essential fields of galaxy evolution such as the triggering of star formation, the feedback of massive stars into the interstellar medium, and the structure and dynamics of the interstellar medium.Comment: to appear in the proceedings to the conference: "The Evolution of Galaxies through the Neutral Hydrogen Window", Arecibo, PR, US

Foucher/Desgabets: Translations from the Cartesian debate on Ideas and Representation

Two kinds of people might find this useful: first, those interested in the modern debate over ideas and representation who don’t happen to read French, or who do, but would like to have in one place the relevant excerpts, to see whether looking at the originals is worth their time. Second are teachers of modern philosophy. The back-and-forth among these figures makes for a refreshing change from the massive, often self-contained works that characterize much of the rest of such a course. For example, one could easily work in chapter 3 (the high point of the debate, from my point of view) between Descartes and Berkeley

The Stellar and Gaseous Contents of the Orion Dwarf Galaxy

We present new KPNO 0.9-m optical and VLA HI spectral line observations of the Orion dwarf galaxy. This nearby (D ~ 5.4 Mpc), intermediate-mass (M_dyn = 1.1x10^10 Solar masses) dwarf displays a wealth of structure in its neutral ISM, including three prominent "hole/depression" features in the inner HI disk. We explore the rich gas kinematics, where solid-body rotation dominates and the rotation curve is flat out to the observed edge of the HI disk (~6.8 kpc). The Orion dwarf contains a substantial fraction of dark matter throughout its disk: comparing the 4.7x10^8 Solar masses of detected neutral gas with estimates of the stellar mass from optical and near-infrared imaging (3.7x10^8 Solar masses) implies a mass-to-light ratio of ~13. New H alpha observations show only modest-strength current star formation (~0.04 Solar masses per year); this star formation rate is consistent with our 1.4 GHz radio continuum non-detection.Comment: Astronomical Journal, in press. Full-resolution version available from http://www.macalester.edu/~jcannon/pubs.htm