It is argued that neither the "theory-informity" of observations nor the Quine-Duhem thesis pose any in principle threat to the objectivity of theory evaluation. The employment of exploratory theories does not generate incommensurability, but on the contrary is responsible for the mensurability and commensurability of explanatory theories, since exploratory theories enable scientists to make observations which are critical in the evaluation of explanatory theories. The employment of exploratory theories and other auxiliary hypotheses does not enable a theory to always accommodate (...) recalcitrant observations to preserve evidential equivalence with a rival theory. Explanatory theories become rapidly degenerating if exploratory theories or other auxiliary hypotheses which inform the original confirmation base are modified to accommodate recalcitrant observations. (shrink)

Several arguments are considered which purport to demonstrate the impossibility of theory-neutral observation. The most important of these infers the continuity of observation with theory from the presumed continuity of perception with cognition, a doctrine widely espoused in recent cognitive psychology. An alternative psychological account of the relation between cognition and perception is proposed and its epistemological consequences for the observation/theory distinction are then explored.

Churchland's paper "Perceptual Plasticity and Theoretical Neutrality" offers empirical, semantical and epistemological arguments intended to show that the cognitive impenetrability of perception "does not establish a theory-neutral foundation for knowledge" and that the psychological account of perceptual encapsulation that I set forth in The Modularity of Mind "[is] almost certainly false". The present paper considers these arguments in detail and dismisses them.

Contrary to the Empiricist model of science, successful sufficiently fundamental theories not only fit and unify their data fields but also prescribe the general terms in which relevantly to describe observation; specify what is and is not observable; specify the conditions under which what is observable, is observable; specify the instrumental means and reliability by which what is measurable is measured; specify what is causally, statistically, and merely accidentally connected. Moreover, such theories typically require all or most of the entire (...) remainder of science to be properly applied in any given situation and theoreticians' models play a crucial role in such applications. (I call these respectively the internal and external globalnesses of theories.) A discussion of the consequences of these global features of theories for philosophy of science is offered in the context of specific examples and a structural model for science. (shrink)

Experimental data are often acclaimed on the grounds that they can be consistently generated. They are, it is said, reproducible. In this paper I describe how this feature of experimental-data (their pragmatic reliability) leads to their epistemic worth (their epistemic reliability). An important part of my description is the supposition that experimental procedures are to certain extent fixed and stable. Various illustrations from the actual practice of science are introduced, the most important coming at the end of the paper with (...) a discussion of Ray Davis' 1967 solar-neutrino detection experiment (as it is portrayed in Pinch, 1980). (shrink)

The concept of observability of entities in physical science is typically analysed in terms of the nature and significance of a dichotomy between observables and unobservables. In the present work, however, this categorization is resisted and observability is analysed in a descriptive way in terms of the information which one can receive through interaction with objects in the world. The account of interaction and the transfer of information is done using applicable scientific theories. In this way, the question of observability (...) of scientific entities is put to science itself. The result is a demonstration that observability has many dimensions, some more epistemically significant than others. (shrink)