A perfectly matched layer (PML) absorbing material composed of a uniaxial anisotropic material is presented for the truncation of finite-difference time-domain (FDTD) lattices. It is shown that the uniaxial PML material formulation is mathematically equivalent to the perfectly matched layer method published by Berenger (see J. Computat. Phys., Oct. 1994). However, unlike Berenger's technique, the uniaxial PML absorbing medium presented in this paper is based on a Maxwellian formulation. Numerical examples demonstrate that the FDTD implementation of the uniaxial PML medium (...) is stable, equal in effectiveness as compared to Berenger's PML medium, while being more computationally efficient. (shrink)

A definition of emotion common to the affective sciences is an urgent desideratum. Lack of such a definition is a constant source of numerous misunderstandings and a series of mostly fruitless debates. There is little hope that there ever will be agreement on a common definition of emotion, given the sacred traditions of the disciplines involved and the egos of the scholars working in these disciplines. Our aim here is more modest. We propose a list of elements for a working (...) definition of emotion and discuss the justification for the inclusion of elements from our respective perspectives (philosophy and psychology). This working partial definition may at least serve as a litmus test to examine theories of emotion, old and new, across disciplinary boundaries. (shrink)

The central contention of this article is that the classificatory scheme of contemporary affective science, with its traditional categories of emotion, anger, fear, and so on, is no longer suitable to the needs of affective science. Unlike psychological constructionists, who have urged the transition from a discrete to a dimensional approach in the study of affective phenomena, I argue that we can stick to a discrete approach as long as we accept that traditional emotion categories will have to be transformed (...) in order to do any scientific work. I conclude by articulating some general rules for turning traditional emotion categories into suitable scientific tools. (shrink)

The word “emotion” has named a psychological category and a subject for systematic enquiry only since the 19th century. Before then, relevant mental states were categorised variously as “appetites,” “passions,” “affections,” or “sentiments.” The word “emotion” has existed in English since the 17th century, originating as a translation of the French émotion, meaning a physical disturbance. It came into much wider use in 18th-century English, often to refer to mental experiences, becoming a fully fledged theoretical term in the following century, (...) especially through the influence of two Scottish philosopher-physicians, Thomas Brown and Charles Bell. This article relates this intellectual and semantic history to contemporary debates about the usefulness and meaning of “emotion” as a scientific term. (shrink)

The target articles and commentaries reveal considerable support for the view that the term “emotion” names neither a natural kind nor a coherent psychological category. This brief response revisits a couple of historical points about the meanings of “emotion,” as well as the ancient debate between Stoicism and Christianity.