Fechner's conception of psychophysics included both “outer psychophysics” the relation between stimulus intensity and the response reflecting sensation strength, and “inner psychophysics” the relation between neurelectric responses and sensation strength. In his own time outer psychophysics focussed on the form of the psychophysical law, with Fechner espousing a logarithmic law, Delboeuf a variant of the logarithmic law incorporating a resting level of neural activity, and Plateau a power law. One of the issues on which the dispute was focussed concerned the (...) appearance of contrasts if the overall illumination was increased or decreased; another issue was the question of whether a sensation of a “just noticeable difference” established for one value of a sensory dimension appeared the same for a value elsewhere on the dimension. The development of “inner psychophysics” led through the works of Delboeuf, Solomons, Jastrow, and Thurstone to modern signal detection theory. A third line of research, devoted to the question of what was meant by the “measurement” of sensation strength, stemmed from the criticism of Fechner's work by von Kries (1882) and others. Although a valid body of science could be built up without the intervening variable called “sensation strength,” such a science might be a cumbersome representation of reality. When an optical contrast is set up, and its overall illumination is increased or decreased, subjective contrasts involving medium levels of lightness vary little as illumination varies (as a power law based on sensation ratios or a logarithmic law based on sensation differences predict), but subjective contrasts involving extreme levels of lightness might be subject to the effects of other variables. (shrink)

It is a matter of some irony that psychiatry's most trenchant critic for over four decades is himself a psychiatrist. I refer to Thomas S. Szasz. Szasz's core thesis may be succinctly rendered: mental illness is a “myth”, a “metaphor” which serves only to obscure the social and ethical “problems in living” we face as human beings. This paper reconsiders the conceptual bases of Szasz's assault on psychiatry and assesses recent counter-arguments of his critical interlocutors. It presents a defence of (...) the Szaszian conception and emphasises the continuing relevance of his earliest work. Additionally, the paper discusses Szasz's thesis in light of the work of the influential French philosopher of medicine, Georges Canguilhem. (shrink)

For some two millennia, Western civilization has predominantly viewed mind and consciousness as the private domain of the human species. Some have been willing to extend these qualities to certain animals. And there has been a small but very significant minority of philosophers who have argued that the processes of mind are universal in extent, and resident in all material things.

Descartes developed an elaborate theory of animal physiology that he used to explain functionally organized, situationally adapted behavior in both human and nonhuman animals. Although he restricted true mentality to the human soul, I argue that he developed a purely mechanistic (or material) ‘psychology’ of sensory, motor, and low-level cognitive functions. In effect, he sought to mechanize the offices of the Aristotelian sensitive soul. He described the basic mechanisms in the Treatise on man, which he summarized in the Discourse. However, (...) the Passions of the soul contains his most ambitious claims for purely material brain processes. These claims arise in abstract discussions of the functions of the passions and in illustrations of those functions. Accordingly, after providing an intellectual context for Descartes’s theory of the passions, especially by comparison with that of Tho- mas Aquinas, I examine its ‘machine psychology’, including the role of habituation and association. I contend that Descartes put forth what may reasonably be called a ‘psychology’ of the unensouled animal body and, correspondingly, of the human body when the soul does not intervene. He thus conceptually distinguished a mechanistically explicable sensory and motor psychology, common to nonhuman and human animals, from true mentality involving higher cognition and volition and requiring (in his view) an immaterial mind. (shrink)

Gerrit Lindeboom’s biography, Herman Boerhaave: The Man and His Work, presents a heroic account of Herman Boerhaave’s life and his many contributions to medicine and medical education. He is portrayed as an outstanding eighteenth century educator who introduced into Leiden’s Medical School a novel method of clinical teaching that was to be widely adopted and today remains at the centre of medical student instruction. Lindeboom’s historiography induced a resurgence of interest in Boerhaave, a renewal of the myth concerning Boerhaave’s innovative (...) teaching and the publication of many acclamatory articles and false epithets, and several critical analyses. Such varying responses prompted this critical examination of the extant Boerhaavian literature, an appraisal of Lindeboom’s objectivity and an assessment of his representations of Boerhaave’s clinical teaching. In doing so, the moral nature of his historiography and that of those who were to sustain his assertions will be established, and the myth that surrounds the novelty and excellence of Boerhaave’s clinical teaching will be evident. (shrink)