The goal of standard semantics is to provide truth conditions for the sentences of a given language. Probabilistic Semantics does not share this aim; it might be said instead, if rather cryptically, that Probabilistic Semantics aims to provide belief conditions.

The central and guiding idea of Probabilistic Semantics is that each rational individual has ‘within’ him or her a personal subjective probability function. The output of the function when given a certain sentence as input represents the degree of likelihood which the individual would assign to that sentence. One can characterize these functions via a set of axioms, and in the terms of this defined structure develop probabilistic analogues of all important semantical notions (e.g. validity, entailment). Then, dealing with ‘being given probability 1’ instead of ‘truth,’ one can proceed to give a completely adequate semantics for the particular language under consideration. The axioms delimiting the class of probability functions are, in fact, chosen with this goal and language in mind.

Modern physicalists frequently offer the generous concession that although dualism is false, it is not a metaphysical impossibility. And it appears that the proper formulation of physicalism allows for this concessionary position. It would be expected that dualists also could accept that while physicalism is false, it too is a metaphysical possibility. I will argue that a careful analysis of physicalism and dualism shows that in fact these concessionary positions cannot be maintained. In particular, the nature of the metaphysical determination relation which holds between matter and mind on both physicalist and dualist views precludes either from allowing that the other is a metaphysical possibility.

Perhaps the Clearest and most impressive use of the Principle of Continuity by Leibniz in the evaluation of a theory is that offered in refutation of the Cartesian laws of motion, as given in his Critical Remarks Concerning the General Part of Descartes' Principles. With regard to the Cartesian laws of impact Leibniz says:

On Article 49. Rule 4. If B, which is moving, is smaller than C, which is at rest, B will be reflected with the velocity it had before the shock while C will remain at rest.

We compute theoretical infrared light curves for several known extrasolar planets. We have constructed a set of routines to calculate the orbital parameters for a given planet and integrate over the planetary disk to determine the total flux density of the planet as it orbits the parent star. We have further developed a spectral synthesis routine to calculate theoretical spectra of extrasolar giant planets from 3–24 $\mu$m. The code requires a temperature-pressure profile as input, calculated by solving the radiative transfer equation; it then calculates continuous opacities and line opacities for water, carbon monoxide, and methane, and finally integrates over the layers of the atmosphere to determine the emergent flux. By integrating the theoretical spectrum over the bandpass of a particular instrument and including realistic instrument noise, we produce a set of multi-wavelength, infrared light curves. Using these light curves, we predict whether a particular known planet can be observed and characterized using the Spitzer Space Telescope, as well as other proposed space-based instruments, such as the Fourier-Kelvin Stellar Interferometer (FKSI) and the James Webb Space Telescope (JWST).

This note aims to make more familiar to philosophers yet another bizarre quantum mechanical effect with disturbing metaphysical implications. It is possible to modify the classic double-slit experiment so that one can register the path of a particle to determine which slit it passes through, and then erase this registered information so that the interference effects which would normally disappear upon registration of the “which path” information are reconstituted. Thus the “trajectory” of particles can be effected by temporally and spatially distant operations on the slit detectors. Nonetheless, no untoward effects (such as superluminal signalling) can result from the operation of the eraser.

Hacking argues against van Fraassen's constructive empiricism by appeal to features of microscopic imaging. Hacking relies on both our practices involving imaging instruments and the structure of the images produced by these micropractices. Van Fraassen's reply is formally correct yet fundamentally unsatisfying. I aim to strengthen van Fraassen's reply, but must then extend constructive empiricism, specifically the central notion of “theoretical immersion.” I argue that immersion is more analogous to entering a virtual reality than to learning a language. This metaphor assimilates instrument-based practice as well as theoretical debate and explanation, and can provide an anti-realist view of our micro-practices consonant with constructive empiricism.

Jerry Fodor has recently proposed a new entry into the list of information based approaches to semantic content aimed at explicating the general notion of representation for both mental states and linguistic tokens. The basic idea is that a token means what causes its production. The burden of the theory is to select the proper cause from the sea of causal influences which aid in generating any token while at the same time avoiding the absurdity of everything's being literally meaningful (since everything has a cause). I argue that a detailed examination of the theory reveals that neither burden can be successfully shouldered.

Prototype ferroelectric thin film, nonvolatile memory, nondestructive readout (NDRO), semiconductor devices have been fabricated. The “1” and “0” logic states of these prototype devices are in principle determined by the modulation of the conductivity of a semiconductor film channel by the polarization state of the underlying ferroelectric thin film layer. Programmed resistance ratios of the two logic states of 5:1 are demonstrated. While the best performance to date has been achieved for devices that have a 40 nm ln2O3 film covering a 300 nm thick PZT 20/80 layer, we also develop criteria for selecting semiconductor films that will improve performance for this NDRO device design. Among the other semiconductor films that are characterized with respect to this criteria are boron doped Ge, ZnO and aluminum doped ZnO. It is demonstrated that by appropriate donor doping of ZnO films the effects of intrinsic defects are masked and that process temperatures can be extended by 300×C.

Psychological Externalism (PE) is the view that the contents of intentional psychological states are determined by factors external to the subject of those states. For example, PE holds that the content of a belief will be established at least in part by features of the environment, broadly construed, around and more or less detached from the believer. The range of such external factors is quite large, and various forms of PE emerge depending on which sorts of factors are endorsed. Generally speaking, these factors are those that establish the reference of the terms used to specify the contents of psychological states. To convey the flavour of this doctrine, let me briefly review some of the candidate external factors.

The ability to observe is the ability to reliably detect, but that is not all observation is. A thermometer reliably detects temperature yet does not observe the temperature, whereas I do, even though in terms of reliability I cannot match the thermometer. An observation is detection accompanied by active classification and, typically, the subsequent formation of opinion. Even when we say of an animal that it can see something we mean more than that it reliably detects things of a certain sort but also that it deals with such things as objects, gauging their usefulness or lack thereof in relation to its interests and to other aspects of the world. This crucial addendum to the notion of observation can be enshrined in slogan: observers are potential believers. This marks the difference between mere detecting mechanisms and observers.

The contemporary scientific anti-realism of one such as van Fraassen, which is developed in detail under the label of “constructive empiricism” in van Fraassen (1980), can be characterized in terms of detecting mechanisms.