“Dualism and the Arguments against Neuroscientific Progress” by P.S. Churchland
In the introduction Dr. Churchland makes the case that the use of reductive explanation is appropriate. She is using a neuroscience framework to further explore ideas of mental phenomena. She explains that the words used in macrobiology can be used when explaining microbiology even though the meanings change. This is done throughout the various scientific disciplines and is no big deal. (pp. 21-23)
She discusses nine arguments against nueroscientific progress for explaining consciousness. (1) I can’t imagine how science could explain awareness. > Not knowing something is not a valid argument for proving something does not exist. It is a fallacy. (2) There could be zombies. > The thought argument describing a human with no qualia (can’t see colors, feel pain, become dizzy; in other words lacking in those experiences) she explains the invalidity of the argument by noting that “many things are logically possible but not empirically possible, for instance a 2-ton mouse. (3) The problem is too hard. > She illustrates with examples, the fallacy of arguing ignorance. The original theory of traits passing generationally from parent to child was that proteins were responsible. However science progressed and what was thought to be an unlikely source, an acid, DNA is the mechanism. (4) How can I know what you experience? > The experience could be seeing color. This is also argued with the words “Conscious experiences are not identifiable with any property of the nervous system.” which rests on the assumption “Our brains could be identical in every respect but our qualia could differ” and that this obviously true.” Dr. Churchland explains that using the “inverted-spectrum argument” doesn’t work because the argument offers no facts to substantiate “i.e. wants to establish and a priori truth.” (5) What happens if we get more empirical? > The argument is too simple and cannot apply to the color experience because there is not a direct relationship between equal distances and equal increments of color discrimination. A 1-dimensional color-inversion thought experiment won’t work because “human phenomenal color space is 3-dimensional. (6) Dualist: the thought experiment is conceivable with an inversion of the metric of the similarity/discriminability relations while at the same time inverting the causal map color qualia on the external world. > Perhaps unless in this way the qualia is changed plus there is no scientific evidence that qualia exists. The dualist is hoist by his own petard. > Succinctly put she says that “thought experiments can be useful exploratory devices, but they have no authority in dictating empirical facts.” (7) So who is right? Since the issue is scientific and there is a scientific explanation available for ‘the opponent-cell activation-space theory of human coding.’ Dr. Churchland suggests the argument resume when dualists can offer a competing argument such as ‘a competing argument for the shape of the Munsell color solid.’ When an issue is scientific different points of view must be evaluated on their ‘respective scientific merits.’ (8) Doesn’t neuroscience leave something out? > For example color blind person cannot see colors as other people do just by learning the theory. She feels the color-opponent theory adequately provides an explanation for “discriminating the colors by spontaneous internal reaction to their intrinsic qualitative natures.” (9) It is ridiculous to expect a reduction from the behavioral level directly to the neuronal level. > This is the argument that consciousness cannot be explained by neurobiology. She says that the mistake people have when they make this argument is that they expect there must be a direct explanation from the idea of consciousness to the proof of consciousness. But that cannot happen in a complex system. (9A) Another argument is that consciousness/awareness cannot be explained by neurobiology but instead by interactions within microtubules in cells. These are protein structures with neurons. Penrose and Hameroff reject the neurobiology argument because they see evidence that awareness is produced by the quantum effects in microtubules. > She disputes their argument on the grounds that they have no hard data and the experimental method is flawed. (Pp.174 -197)
Dr. Churchland concludes that in her review of “brain-based explanations for conscious phenomena” the one undisputed argument from her is that the “inverted spectrum” thought experiment leads to many more problems without solving anything.
Hoy, R.C. & Oaklander, N.L. (2004) Metaphysics: Classic and Contemporary Readings.
Wadsworth Publishing. 2nd Ed.