DHARMAKIRTI, DAVIDSON, AND KNOWING REALITY

If we distinguish phenomenal effects from their noumenal causes, the former being our conceptual(ized) experiences, the latter their grounds or causes in reality as it is independent of our experience, then two contradictory positions with regards to the relationship between these two can be distinguished: either phenomena are identical with their noumenal causes, or they are not. Davidson is among the most influential modern defenders of the former position, metaphysical non-dualism. Dharmakirti\u27 strict distinction between ultimate and conventional reality, on the other hand, may be one of the most rigorously elaborated theories of the opposite position, metaphysical dualism. Despite this fundamental difference, their theories about the connection between phenomena and their noumenal causes are surprisingly similar in important respects. Both Dharmakirti in his theory of apoha and Davidson in his theory of triangulation argued that the content of words or concepts depends on a process involving at least two communicating beings and shared noumenal stimuli. The main point of divergence is the nature of classification, but ultimately Dharmakirti\u27s and Davidson\u27s conclusions on the noumenal-phenomenal relationship turn out to be complementary more than contradictory, and an integrative reconstruction suggests a middle path between dualism and non-dualism

Aphantasia, SDAM, and Episodic Memory

Episodic memory (EM) involves re-experiencing past experiences by means of mental imagery. Aphantasics (who lack mental imagery) and people with severely deficient autobiographical memory (SDAM) lack the ability to re-experience, which would imply that they don't have EM. However, aphantasics and people with SDAM have personal and affective memories, which are other defining aspects of EM (in addition to re-experiencing). This suggests that these supposed aspects of EM really are independent faculties or modules of memory, and that EM is a composite faculty rather than a natural kind. Apparent varieties of (normal and "defective") EM (as well as some closely related kinds of memory) are different combinations of these modules, and the EM construct itself adds little if any explanatory value to these modules

The Problem of the Rock and the Grammar of Consciousness

The “Problem of the Rock” (PoR) is a famous objection to Higher-Order (HO) theories of consciousness. According to PoR, the HO theorists’ claim that a mental state is conscious iff there is a higher-order mental state about it implies that a rock is also conscious iff there is a higher-order mental state about it. In this paper I show that this argument confuses two grammatically distinct attributions of consciousness, and that if the consequent equivocation fallacy is avoided, PoR is either a straw man argument or has an unproblematic conclusion

Postscript: Reply to McLeod

This is my reply to McLeod’s reply (2015a) to my (2015) paper commenting on his (2011) interpretation of Wang Chong 王充 as an alethic pluralist

Philosophy of mental time — A theme introduction

(First paragraphs.) — The notion of “mental time” refers to the experience and awareness of time, including that of past, present, and future, and that of the passing of time. This experience and awareness of time raises a number of puzzling questions. How do we experience time? What exactly do we experience when we experience time? Do we actually experience time? Or do we infer time from something in, or some aspect of our experience? And so forth. These and many related questions in the “philosophy of mental time”, the topic of this special issue of the Annals of the Japan Association for Philosophy of Science, are not purely philosophical questions. Or at least, they are not likely to be satisfactorily answered by philosophers alone. Rather, they also need the input of neuroscientists, psychologists, physicists, linguists, and others. And conversely, answers to these questions may have implications outside the scope of philosophy. The papers in this special issue illustrate this inherent multi- or interdisciplinarity of the philosophy and science of mental time. In this theme introduction, we want to give a few more examples to illustrate this interdisciplinarity, but also to point out that much of the field is still wide open—that is, these illustrations raise more questions than answers

Transition between advection and inertial wave propagation in rotating turbulence

In turbulent flows subject to strong background rotation, the advective mechanisms of turbulence are superseded by the propagation of inertial waves, as the effects of rotation become dominant. While this mechanism has been identified experimentally (Dickinson & Long, J. Fluid Mech., vol. 126, 1983, pp. 315–333; Davidson, Staplehurst & Dalziel, J. Fluid Mech., vol. 557, 2006, pp. 135–144; Staplehurst, Davidson & Dalziel, J. Fluid Mech., vol. 598, 2008, pp. 81–105; Kolvin et al.Phys. Rev. Lett., vol. 102, 2009, 014503), the conditions of the transition between the two mechanisms are less clear. We tackle this question experimentally by tracking the turbulent front away from a solid wall where jets enter an otherwise quiescent fluid. Without background rotation, this apparatus generates a turbulent front whose displacement recovers the law classically obtained with an oscillating grid (Dickinson & Long, Phys. Fluids, vol. 21 (10), 1978, pp. 1698–1701) and we further establish the scale independence of the associated transport mechanism. When the apparatus is rotating at a constant velocity perpendicular to the wall where fluid is injected, not only does the turbulent front become mainly transported by inertial waves, but advection itself is suppressed because of the local deficit of momentum incurred by the propagation of these waves. Scale-by-scale analysis of the displacement of the turbulent front reveals that the transition between advection and propagation is local both in space and spectrally, and takes place when the Rossby number based on the considered scale is of order unity, or equivalently, when the scale-dependent group velocity of inertial waves matched the local advection velocity

Experimental vortex breakdown topology in a cylinder with a free surface.

The free surface flow in a circular cylinder driven by a rotating bottom disk is studied experimentally using particle image velocimetry. Results are compared with computational results assuming a stress-free surface. A dye visualization study by Spohn et al.. We confirm the existence of a transition where the top of the breakdown bubble crosses from the axis to the surface, which has previously only been found numerically. We employ a technique by Brøns et al

Mean flow anisotropy without waves in rotating turbulence

We tackle the question of how anisotropy in flows subject to background rotation favours structures elongated along the rotation axis, especially in turbulent flows. A new, wave-free mechanism is identified that challenges the current understanding of the process. Inertial waves propagating near the rotation axis are generally accepted as the most efficient mechanism to transport energy anisotropically. They have been shown to transfer energy to large anisotropic, columnar structures. Nevertheless, they cannot account for the formation of simpler steady anisotropic phenomena such as Taylor columns. Here, we experimentally show that more than one mechanism involving the Coriolis force may promote anisotropy. In particular, in the limit of fast rotation, that is at low Rossby number, anisotropy favouring the direction of rotation of the average of a turbulent flow arises neither because of inertial waves nor following the same mechanism as in steady Taylor columns, but from an interplay between the Coriolis force and average advection.Comment: 17 pages, 10 figures, submitted to Jour. Fluid Mec

Dharmakīrti, Davidson, and knowing reality

If we distinguish phenomenal effects from their noumenal causes, the former being our conceptual(ized) experiences, the latter their grounds or causes in reality ‘as it is’ independent of our experience, then two contradictory positions with regards to the relationship between these two can be distinguished: either phenomena are identical with their noumenal causes, or they are not. Davidson is among the most influential modern defenders of the former position, metaphysical non-dualism. Dharmakīrti’s strict distinction between ultimate and conventional reality, on the other hand, may be one of the most rigorously elaborated theories of the opposite position, metaphysical dualism. Despite this fundamental difference, their theories about the connection between phenomena and their noumenal causes are surprisingly similar in important respects. Both Dharmakīrti in his theory of ‘apoha’ and Davidson in his theory of ‘triangulation’ argued that the content of words or concepts depends on a process involving at least two communicating beings and shared noumenal stimuli. The main point of divergence is the nature of classification, but ultimately Dharmakīrti’s and Davidson’s conclusions on he noumenal - phenomenal relationship turn out to complementary more than contradictory, and an integrative reconstruction suggests a ‘middle path’ between dualism and non-dualism

Smart SQUIDs based on Relaxation Oscillation SQUIDs

Smart SQUIDs based on double Relaxation Oscillation SQUIDs (DROS) and a superconducting up-down counter have been developed. DROS and counter form a flux locked loop on one single chip. The DROS output consists of a series of pulses that controls the two up and down write gates of the counter. The pulsed output structure of the DROS constitutes the internal clock for this single-chip device. Several prototypes were built with a clock frequency of 100 MHz, a linear operation flux range of about 2.5 ¿0, and a white noise level of 6.5 ¿¿0/¿Hz. The smart SQUID is in principle a promising device for application in multichannel SQUID system