Archive for January, 2013

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Surface Tensions: Challenges to Philosophy of Science from Nanoscience

January 31, 2013

Julia Bursten

Abstract: A traditional view of the structure of scientific theories, on which philosophers of science have based their accounts of explanation, modeling, and inter-theory relations, holds that scientific theories are composed of universal natural laws coupled with initial and boundary conditions. In this picture, universal laws play the most significant role in scientific reasoning. Initial and boundary conditions are rarely differentiated and their role in reasoning is largely overlooked. In this talk, I use the problem of modeling surfaces in nanoscience to show why this dismissal is deeply problematic both for philosophers of science and for scientists themselves.

In macroscopic-scale modeling, surfaces are treated as boundaries in the mathematical sense-that is, as infinitesimally thin borders of a system that confine its interior. As such, surface structure and behavior is usually modeled in an idealized manner that ignores most of the physics and chemistry occurring there. At the nanoscale, however, the structure and behavior of these surfaces significantly constrains the structure and behavior of the interior in more complex ways. Three important conclusions emerge:

1. The very concept surface changes as a function of scale, and other central concepts in nanoscience also behave in this scale-dependent manner.
2. The traditional view of theory described above does not adequately capture the nature of nanomaterials modeling, which requires attention to multiple models constructed at different characteristic scales. These component models do not comport well with a single set of universal laws, as the standard view suggests. Instead, boundary behaviors become crucial and models are designed to capture these behaviors.
3. The projects of nanomaterials modeling and synthesis dictate that divisions between boundaries and interiors must be continually adjusted. Overlooking this problem has led to failures of experimental design and interpretation of data.

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The Use of Usus and the Function of Functio: Teleology and its Limits in Descartes’ Physiology

January 11, 2013
Peter M. Distelzweig
Descartes frequently, explicitly, and controversially rejected appeals to final causes (glossed as divine ends) in natural philosophy. Nonetheless, Descartes employs the apparently teleological language of functio and usus in his physiology. Recently, scholars have given increased attention to the nature, extent, and consistency of this apparent teleology. However, little consensus has emerged. In this paper I examine this interpretive difficulty employing a new, two-pronged strategy. I seek to overcome the potential ambiguities in Descartes language by (1) turning our attention especially to the explanatory structures Descartes uses and by (2) focusing on the medical context of his physiology and the language of usus and functio. I employ work on the concept of ‘function’ in contemporary philosophy of biology in order to clarify my interpretive claims.
I argue that Descartes intends and primarily does employ usus and functio to provide ‘function-analytical’ explanations of the complex behavior of organisms and their organ systems. This was a familiar project, exemplified in (e.g.) the work of Jean Fernel (an influential medical writer of the 16th century). In it, usus are treated like Cummins-functions. Descartes’ goal in his physiology is to provide mechanical explanations to replace the metaphysically more extravagant versions in the medical tradition. I argue further that Descartes, nonetheless, does occasionally employ explanations like the final causal explanations characteristic of the work of anatomists Hieronymus Fabricius ab Aquapendente and his more famous student, William Harvey. In these, usus are treated like Wright-functions. I analyze two examples in Descartes: his explanation of the bicuspid character of the mitral valve of the heart and his explanation of the pscho-corporeal physiology of sensation. Finally, I argue that this kind of explanation is problematic for Descartes’ system: his only explicit strategy for grounding such explanations (appealing to divine non-deceptiveness) has significant difficulties—especially in the case of the mitral valve.