142 research outputs found
[Cogigata physico-mathematica = Opera varia mathematica]
Copia digital. Madrid : Ministerio de Cultura. Subdirección General de Coordinación Bibliotecaria, 200
Exact Optics: A unification of optical telescope design
A perfect focus telescope is one in which all rays parallel to the axis meet
at a point and give equal magnification there. It is shown that these two
conditions define the shapes of both primary and secondary mirrors. Apart from
scale, the solution depends upon two parameters, , which gives the mirror
separation in terms of the effective focal length, and , which gives the
relative position of the final focus in that unit. The two conditions ensure
that the optical systems have neither spherical aberration nor coma, no matter
how fast the ratio. All known coma--free systems emerge as approximate
special cases. In his classical paper, K. Schwarzschild studied all two mirror
systems whose profiles were conic sections. We make no such a priori shape
conditions but demand a perfect focus and solve for the mirrors' shapes.Comment: 11 pages, LaTex ([alleqno,epsfig]{mn}), 7 Figures (eps), accepted by
MNRA
Prodromes of Descriptive Geometry in the Traité de stéréotomie by Amédée François Frézier
Tres medici, duo athei? The Physician as Atheist and the Medicalization of the Soul
Until recently, examinations of the ‘mind-body problem’ in historical context paid only cursory attention to its specifically medical dimension, if at all. At best, some ‘folk physiology’ was entertained, usually to laugh at it (the pineal gland, animal spirits). Conversely, historians of neuroscience or of artificial intelligence (Jeannerod 1985, Dupuy 2000) often present figures like La Mettrie as heroic early cases of ‘naturalization’, giving an experimental basis to materialism: their symmetrically inverse mistake is to take professions of medical authority too literally (although there are genuine cases where all of the above does coalesce – where ‘actors’ categories mysteriously transcend historiographic projections –, such as Hieronymus Gaub’s reflections on the ‘regimen of the mind’ in the mid-eighteenth century, or, more theoretically, Guillaume Lamy’s Epicurean-inflected Anatomical Discourses on the Soul, eighty years earlier). Contrary to the denial of the relevance of medicine in early modern philosophy, as regards issues such as the body-soul (then body-mind) relation among others, it seems patently difficult to separate medical theory, medically nourished philosophical speculation, and metaphysics. This is the case, whether in Descartes, Gaub, the ‘animist’ Georg-Ernest Stahl, or materialists such as Guillaume Lamy and La Mettrie: medicine, or rather ‘a certain idea of medicine’, is everywhere.
Here I focus on the motif of a radical medicine – a medical precursor of the Radical Enlightenment (Israel 2001, 2006, 2007), symbolized negatively by the slogan, tres medici, duo athei, or ‘where there are three doctors, there are two atheists’, i.e. medicine as a basis for atheism. This theme runs through various works of medical or medico-theological propaganda: Thomas Browne’s 1643 De religio medici begins with Browne regretting rumors of doctors being atheists as the “general scandal of my Profession”; Germain de Bezançon’s 1677 Les médecins à la censure works hard at rebutting the saying, “Bon Physicien, mauvais chrétien.” But these are examples of the fear of a radical medicine – a medicine that denies the existence of an immortal soul, or even defends materialism and atheism. Are there positive statements of this doctrine? Indeed, attacks on it are much more common than statements identifying with it, like medical versions of natural theology in general.
In fact, just as there were theologically motivated medical works, there were also medically motivated works of radical or heretical theology, like William Coward’s Second Thoughts on the Human Soul (Coward 1702, building on Overton 1644), which engaged in polemics concerning the nature of the soul – mortal or immortal? (Thomson 2008). Parallel to the mortalist trend, but flowing into a common genre of radical, medico-materialist texts (sometimes anonymous, such as L’Âme Matérielle, from the 1720s) are at least two other strands of radical medicine: a post-Cartesian focus on medicina mentis and the nature of the mind (Henricus Regius, Hieronymus Gaub, Antoine Le Camus), and an Epicurean medicine, in which mind and body are organismically united, with an additional hedonistic component, notably in Lamy, Mandeville and La Mettrie (Wright 1991, Wolfe and van Esveld 2014). The focus on a medicine of the mind (Corneanu, ms. 2013) is obviously connected to a ‘medicalization of the soul’: there was a body-soul problem in and for medicine, a sort of medicalized ‘pneumatology’. Radical medicine is located somewhere in between the early forms of ‘naturalization’ or ‘medicalization’ of the soul and the pose of scientific neutrality that is characteristic of early nineteenth-century medicine (as in Cabanis, Bichat or Bernard): it is a short-lived episode. I seek to reconstruct this intellectual figure, in which mortalist, post-Cartesian and Epicurean strands intersect and sometimes come together. I suggest that medically influenced materialism in the Radical Enlightenment (e.g. in the later French cases, La Mettrie, Ménuret and Diderot), is different from later, more experimentally focused and more quantitatively oriented forms of medical materialism, precisely because of its radical dimension. This radical medicine often insists on vitality, as opposed to “anatomie cadavérique”: it is vital and hedonistic, a medicine concerned with maintaining bodily pleasure.Until recently, examinations of the 'mind-body problem' in historical context paid only cursory attention to its specifically medical dimension, if at all. At best, some 'folk physiology' was entertained, usually to laugh at it (the pineal gland, animal spirits). Conversely, historians of neuroscience or of artificial intelligence (Jeannerod M, The brain machine. The development of neurophysiological thought, trans. D. Urion, Harvard University Press, Cambridge, 1985; Dupuy J-P, The mechanization of the mind: on the origins of cognitive science, trans. M.B. DeBevoise, Princeton University Press, Princeton, 2000) often present figures like La Mettrie as heroic early cases of 'naturalization', giving an experimental basis to materialism: their symmetrically inverse mistake is to take professions of medical authority too literally (although there are genuine cases where all of the above does coalesce where 'actors' categories mysteriously transcend historiographic projections -, such as Hieronymus Gaub's reflections on the 'regimen of the mind' in the mid-eighteenth century, or, more theoretically, Guillaume Lamy's Epicurean-inflected Anatomical Discourses on the Soul, eighty years earlier). Contrary to the denial of the relevance of medicine in early modern philosophy, as regards issues such as the body-soul (then body-mind) relation among others, it seems patently difficult to separate medical theory, medically nourished philosophical speculation, and metaphysics. This is the case, whether in Descartes, Gaub, the 'animist' Georg-Ernest Stahl, or materialists such as Guillaume Lamy and La Mettrie: medicine, or rather 'a certain idea of medicine', is everywhere.Here I focus on the motif of a radical medicine - a medical precursor of the Radical Enlightenment (Israel J, Radical enlightenment. Philosophy and the making of modernity, 1650-1750, Oxford University Press, Oxford, 2001; Israel J, Enlightenment contested. Oxford University Press, Oxford, 2006, Israel J, Enlightenment, radical enlightenment and the "medical revolution" of the late seventeenth and eighteenth centuries. In: Grell OP, Cunningham A (ed) Medicine and religion in enlightenment Europe. Ashgate, Aldershot, pp 5-28, 2007), symbolized negatively by the slogan, tres medici, duo athei, or 'where there are three doctors, there are two atheists', i.e. medicine as a basis for atheism. This theme runs through various works of medical or medico-theological propaganda: Thomas Browne's 1643 De religio medici begins with Browne regretting rumors of doctors being atheists as the "general scandal of my Profession"; Germain de Bezancon's 1677 Les medecins a la censure works hard at rebutting the saying, "Bon Physicien, mauvais chretien." But these are examples of the fear of a radical medicine - a medicine that denies the existence of an immortal soul, or even defends materialism and atheism. Are there positive statements of this doctrine? Indeed, attacks on it are much more common than statements identifying with it, like medical versions of natural theology in general.In fact, just as there were theologically motivated medical works, there were also medically motivated works of radical or heretical theology, like William Coward's Second Thoughts on the Human Soul (Coward W, Second thoughts on the human soul. R. Basset, London, 1702, building on Overton 1644), which engaged in polemics concerning the nature of the soul - mortal or immortal? (Thomson A, Bodies of thought: science, religion, and the soul in the early enlightenment. Oxford University Press, Oxford, 2008). Parallel to the mortalist trend, but flowing into a common genre of radical, medico-materialist texts (sometimes anonymous, such as L'Ame Materielle, from the 1720s) are at least two other strands of radical medicine: a post-Cartesian focus on medicina mentis and the nature of the mind (Henricus Regius, Hieronymus Gaub, Antoine Le Camus), and an Epicurean medicine, in which mind and body are organismically united, with an additional hedonistic component, notably in Lamy, Mandeville and La Mettrie (Wright JP, Locke, Willis, and the seventeenth-century epicurean soul. In: Osler MJ (ed) Atoms, Pneuma, and Tranquillity: Epicurean and stoic themes in European thought. Cambridge University Press, Cambridge, pp 239-258, 1991; Wolfe CT, van Esveld M, The material soul: strategies for naturalising the soul in an early modern epicurean context. In: Kambaskovic D (ed) Conjunctions: body, soul and mind from Plato to the enlightenment. Springer, Dordrecht, pp 371-421, 2014). The focus on a medicine of the mind (Corneanu, (ms. 2013), The care of the whole man: medicine and theology in the late renaissance, 2013) is obviously connected to a 'medicalization of the soul': there was a body-soul problem in and for medicine, a sort of medicalized 'pneumatology'. Radical medicine is located somewhere in between the early forms of 'naturalization' or 'medicalization' of the soul and the pose of scientific neutrality that is characteristic of early nineteenth-century medicine (as in Cabanis, Bichat or Bernard): it is a short-lived episode. I seek to reconstruct this intellectual figure, in which mortalist, post-Cartesian and Epicurean strands intersect and sometimes come together. I suggest that medically influenced materialism in the Radical Enlightenment (e.g. in the later French cases, La Mettrie, Menuret and Diderot), is different from later, more experimentally focused and more quantitatively oriented forms of medical materialism, precisely because of its radical dimension. This radical medicine often insists on vitality, as opposed to "anatomie cadaverique": it is vital and hedonistic, a medicine concerned with maintaining bodily pleasure
Cortical Resonance Frequencies Emerge from Network Size and Connectivity
Neural oscillations occur within a wide frequency range with different brain regions exhibiting resonance-like characteristics at specific points in the spectrum. At the microscopic scale, single neurons possess intrinsic oscillatory properties, such that is not yet known whether cortical resonance is consequential to neural oscillations or an emergent property of the networks that interconnect them. Using a network model of loosely-coupled Wilson-Cowan oscillators to simulate a patch of cortical sheet, we demonstrate that the size of the activated network is inversely related to its resonance frequency. Further analysis of the parameter space indicated that the number of excitatory and inhibitory connections, as well as the average transmission delay between units, determined the resonance frequency. The model predicted that if an activated network within the visual cortex increased in size, the resonance frequency of the network would decrease. We tested this prediction experimentally using the steady-state visual evoked potential where we stimulated the visual cortex with different size stimuli at a range of driving frequencies. We demonstrate that the frequency corresponding to peak steady-state response inversely correlated with the size of the network. We conclude that although individual neurons possess resonance properties, oscillatory activity at the macroscopic level is strongly influenced by network interactions, and that the steady-state response can be used to investigate functional networks
Les questions theologiques, physiques, morales et mathematiques...
composées par L. P. M.Verfasser nach Catalogue général des livres imprimés de la Bibliothèque Nationale: Marin Mersenn
Universae Geometriae mixtaeque Mathematicae Synopsis, et bini refractionum demonstratarum tractatus
studio & opera F.M. Mersenni M.Titelvignett
F. Marini Mersenni ordinis minorum S. Francisci de Paula Quaestiones celeberrimae in Genesim, cum ac curata textus explicatione. In hoc volumine athei, et deistae impugnantur, e expurguntur, e vulgata editio ab haereti corum calumnijs vindicantur.
Graecorum, e Hebraeorum musica instauratur. Francisci Georgii Veneti cabalistica dogmata fus e refelluntur, quae passim in illius problematibus habentur. ... Cum indice quadruplici ..
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