31 research outputs found

    Explanatory pluralism in the medical sciences: theory and practice

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    Explanatory pluralism is the view that the best form and level of explanation depends on the kind of question one seeks to answer by the explanation, and that in order to answer all questions in the best way possible, we need more than one form and level of explanation. In the first part of this article, we argue that explanatory pluralism holds for the medical sciences, at least in theory. However, in the second part of the article we show that medical research and practice is actually not fully and truly explanatory pluralist yet. Although the literature demonstrates a slowly growing interest in non-reductive explanations in medicine, the dominant approach in medicine is still methodologically reductionist. This implies that non-reductive explanations often do not get the attention they deserve. We argue that the field of medicine could benefit greatly by reconsidering its reductive tendencies and becoming fully and truly explanatory pluralist. Nonetheless, trying to achieve the right balance in the search for and application of reductive and non-reductive explanations will in any case be a difficult exercise

    The ontology of organisms: Mechanistic modules or patterned processes?

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    Though the realm of biology has long been under the philosophical rule of the mechanistic magisterium, recent years have seen a surprisingly steady rise in the usurping prowess of process ontology. According to its proponents, theoretical advances in the contemporary science of evo-devo have afforded that ontology a particularly powerful claim to the throne: in that increasingly empirically confirmed discipline, emergently autonomous, higher-order entities are the reigning explanantia. If we are to accept the election of evo-devo as our best conceptualisation of the biological realm with metaphysical rigour, must we depose our mechanistic ontology for failing to properly “carve at the joints” of organisms? In this paper, I challenge the legitimacy of that claim: not only can the theoretical benefits offered by a process ontology be had without it, they cannot be sufficiently grounded without the metaphysical underpinning of the very mechanisms which processes purport to replace. The biological realm, I argue, remains one best understood as under the governance of mechanistic principles

    The optical properties of (TMTSF)₂ReO₄ and (TMTSF)₂BF₄ above and below their metal-insulator transitions

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    The reflectivity of large single crystals of protonated and deuterated (TMTSF)₂Re0₄ and (TMTSF)₂BF₄ has been measured from ≈ 30 cm-Âč to ≈ 8000 cm-Âč using a Bruker IFS 113V Fourier Transform Interferometer for Ea and Eb' above and below the metal--insulator transitions at 177 K and 39 K respectively. The infrared powder absorption spectra of protonated and deuterated (TMTSF)₂Re0₄ has been measured from 200 cm˗Âč to 2000 cm˗Âč. The Kramers-Kronig optical conductivity has been calculated from the reflectivity using Drude extrapolations to high frequency. The results for the conductivity for Ea show a one-dimensional density of states, characteristic of a one-dimensional semiconductor with strong electron-phonon coupling, with the vibrations appearing as resonances below the gap and as antiresonances above. The Eb' conductivity is smaller by almost two orders of magnitude than that for Ea, but displays the same semiconducting behavior. The phonons active in the Eb' polarization appear only as resonances. A normal coordinate analysis has been performed for protonated and deuterated TMTSF⁰ and TMTSFâș. The results have been used to infer the frequencies of vibration and the deuterium shifts of TMTSFâș⁰Ś„⁔. The molecular frequencies of vibration have been assigned on the basis of their observed frequencies and optical polarization, as well as their deuterium shifts. Some external phonons have also been assigned. The observation that many of the internal and external vibrations are split is due to the eightfold increase in the size of the unit cell (and subsequent reduction of the Brillouin zone) below the metal-insulator transition. The optical properties of the semiconducting state have been modelled for a one--dimensional molecular conductor with a twofold-commensurate charge-density wave, which accurately reproduces the effects of the lattice dimerization and the potential due to the anion chains. The calculations yield the electron-molecular-vibrational coupling constants for the totally symmetric a[formula omitted] vibrations of the TMTSF molecule. The model also yields a transfer integral of 1400 cm-Âč for both materials and semiconducting energy gaps of 2Δ = 1700 cm˗Âč and 2Δ = 1120 cm˗Âč for (TMTSF)₂ReO₄ and (TMTSF)₂BF₄ respectively. The optical conductivity in the Eb' polarization has been discussed in -terms of a two-dimensional band structure with anisotropic transfer integrals. The band structure calculations show the same general features as the measured spectra.Science, Faculty ofPhysics and Astronomy, Department ofGraduat
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