Parts and Properties in Aristotle\u27s Categories

Call a property recurrent if it can be found in more than one subject, and nonrecurrent otherwise. The question whether Aristotle holds that there are nonrecurrent properties has spawned a lively debate among recent commentators. An assumption held in common by both sides of the debate is that a property is nonrecurrent if it is inseparable from an individual subject. In this paper, I’ll argue that this assumption is false. There are a variety of kinds of separation in Aristotle. When we focus attention on what notion of separation is relevant, we will see that the inseparability possessed by individual properties is neutral on the question whether such properties are recurrent or nonrecurrent. In particular. I’ll ; argue that Aristotle is only claiming that inherent properties, unlike parts, cannot; be severed from their subjects

Aristotle on Consciousness

Aristotle sometimes draws analogies between perceiving and thinking. One analogy, for example, concerns the relation holding between faculties and their objects. If thinking is like perceiving, then as the faculty of perception is to the object perceived, so too the faculty of thought is to the intelligible object. Of course, there are also disanalogies between perception and thought. For example, where perception requires external stimulation by sensible substances, thought does not generally require external stimulation. How far then might we push the analogy? In this essay, I’ll argue that the role of the agent intellect in thought is analogous to the role of perceiving that we see and hear in perception

Injury prevention/exercise in the elderly

This issue of eMedRef provides information to clinicians on how exercise might prevent injury in the elderly

Soliton dynamics in the multiphoton plasma regime

Solitary waves have consistently captured the imagination of scientists, ranging from fundamental breakthroughs in spectroscopy and metrology enabled by supercontinuum light, to gap solitons for dispersionless slow-light, and discrete spatial solitons in lattices, amongst others. Recent progress in strong-field atomic physics include impressive demonstrations of attosecond pulses and high-harmonic generation via photoionization of free-electrons in gases at extreme intensities of 1014 Wcm2. Here we report the first phase-resolved observations of femtosecond optical solitons in a semiconductor microchip, with multiphoton ionization at picojoule energies and 1010 Wcm2 intensities. The dramatic nonlinearity leads to picojoule observations of free-electron-induced blue-shift at 1016 cm3 carrier densities and self-chirped femtosecond soliton acceleration. Furthermore, we evidence the time-gated dynamics of soliton splitting on-chip, and the suppression of soliton recurrence due to fast free-electron dynamics. These observations in the highly dispersive slow-light media reveal a rich set of physics governing ultralow-power nonlinear photon-plasma dynamics.Comment: 14 pages (main body and supplement), 11 figures - earlier draft; http://www.nature.com/srep/2013/130122/srep01100/full/srep01100.htm

Aristotle on Mathematical Existence

Do mathematical objects exist in some realm inaccessible to our senses? It may be tempting to deny this. For one thing, how we could come to know mathematical truths, if such knowledge must arise from causal interaction with non-empirical objects? However, denying that mathematical objects exist altogether has unsettling consequences. If you deny the existence of mathematical objects, then you must reject all claims that commit you to such objects, which means rejecting much of mathematics as it is standardly understood. For, as David Papineau (1990) vividly puts it, it is doublethink to deny that mathematical objects exist but to continue to believe, for example, that there are two prime numbers between ten and fifteen. Two current responses to this problem are literalism and fictionalism. Both literalists and fictionalists deny the existence of a world of mathematical objects distinct from the empirical world. But they differ markedly in this denial. Literalists argue that mathematical objects simply exist in the empirical world; on this account, mathematical assertions assert true beliefs about perceivable objects. Fictionalists, on the other hand, hold that, strictly speaking, mathematical objects do not exist at all, and so exist in neither the empirical world nor in some realm distinct from the empirical world. They argue that mathematical objects are not actual objects but rather harmless fictions; on this account, mathematical assertions do not assert true beliefs about the world but merely fictional attitudes. Although these two positions are apparently quite opposed to one another, they nonetheless have been both ascribed to Aristotle. Indeed, as I’ll argue, Aristotle’s philosophy of mathematics exhibits some of the features characteristic of literalism and some of the features characteristic of fictionalism. However, Aristotle’s position also exhibits features interestingly different from both literalism and fictionalism. The paper comes in three parts. In the first part, I’ll quickly survey the variety of descriptions which Aristotle uses to characterize the relation between mathematical objects and the perceivable world. This will help to explain how apparently opposed positions have been ascribed to Aristotle. In the second part, I’ll discuss literalism in contemporary philosophy of mathematics, the ascription of literalism to Aristotle and the points of agreement and disagreement between Aristotle and literalists. In the third and final part of the paper, I’ll discuss fictionalism in contemporary philosophy of mathematics, the ascription of fictionalism to Aristotle and the points of agreement and disagreement between Aristotle and fictionalists

Ontological Independence in Aristotle\u27s Categories

Aristotle holds that substances (such as you and me) are ontologically independent from nonsubstances (such as our qualities and quantities) but nonsubstances are ontologically dependent on substances. There is then an asymmetry between substances and nonsubstances with respect to ontological dependence. Such asymmetry is widely and rightly thought to be a lynchpin of Aristotelian metaphysics. What is really real for Aristotle are such ordinary objects as you and me. Our properties - my paleness, your generosity - inhabit Aristotle\u27s ontology only in so far as they are ours. This much we can all agree on; and I\u27ll only briefly rehearse one of the reasons for ascribing this picture to Aristotle below. For I agree with the orthodoxy that substances enjoy a certain kind of ontological dependence from nonsubstances - an independence which nonsubstances lack with respect to substances. But I disagree with the orthodoxy as to what kind of ontological independence substances have and nonsubstances lack. Under the orthodox interpretation, the ontological independence ascribed to substances and denied of nonsubstances is a capacity for separate existence. But, I\u27ll argue, there\u27s a tension between substances and nonsubstances with respect to ontological independence