11
(9) Electrophysiological results, demonstrating that unconscious brain processes (marked by a
"readiness potential") occur at least 0,35 seconds before the conscious intention to act, were first
interpreted by Eccles (1985, and in Eccles and Creutzfeldt, 1990, p. 207) as preconditions for the
mind which grasps them, as an "incubation time of the selfconscious mind" (up to 0,8 seconds
long), and as neural correlates or consequences of voluntary commands not exclusively
determined in a neural way (Eccles, 1978, p. 1149, Popper and Eccles, 1977, p. 365, 293, 285) -
contrary to the subjective reports. Later, Eccles (1994a, 138, and 1994c, 220 f.) simply denied the
readiness potential without arguments or experimental data as an "artefact produced by the
averaging technique of recording". However, the easiest explanation is that the readiness potential
is the effect of neural input into the supplementary motor area from axons coming from other cortex
areas (especially the prefrontal cortex) or the thalamus. Thus, there is no need for an intervention
from another ontological realm (cf. Churchland, 1981).
(10) Finally, Eccles (1994a, p. 110) stipulates that the "transmission of psychon to psychon could
explain the unity of our perceptions and of the inner world of our mind that we continually experience
from moment to moment"; "it is the very nature of psychons to link together in providing a unified
experience" (p. 136), the neural machinery cannot do it by itself (p. 22). But this is just a claim
without argument and does not explain at all how sensory information was bound together by
psychons. Even worse, it seems impossible to study such psychonic integrations in principle,
because there is no way to break their connections if they aren't physical. So Eccles' suggestion, at
least in this part, is not a scientific hypothesis at all. Neural accounts of the binding problem
however are within experimental reach. Synchronous activities between neurons from different
parts of the brain are promising candidates for a solution of the binding problem at least with regard
to sensory integration (cf. Singer, 1996).
In conclusion, Eccles' neurophilosophical arguments fail to support his metaphysical speculations
about the ontological difference between brain and mind and their neo-Cartesian interaction. Eccles
cannot show by scientific reasoning what he claims.
III.5. "Wild Thing" Or "Stranger Than Fiction" - Toward A Naturalistic Theory Of Mind
The discovery of NCC cannot establish a naturalistic theory of mind alone because of the already
mentioned conceptual, empirical and ontological reasons (see II., cf. also Vaas, 1995a). There is a
variety of possible ontologies which are all consistent with the existence of NCC. This is not to say,
however, that the discovery and study of NCC is irrelevant for consciousness research and
philosophy of mind. It is always easy to construct weird, unfalsifiable metaphysical claims linking
consciousness to some spooky angel dust, free-floating ghosts, sentient quantum particles or even
blood pressure. As long as there is no empirical evidence, nobody needs to take such strange
speculations seriously. It should be evident that the proponent of such speculations, not the
opponent, has the burden of proof, because they are unfalsifiable. And it is quite wise to apply
Ockham's razor here - i.e., the principle of ontological parsimony ("Pluralitas non est ponenda sine
necessitate; essentia non sunt multiplicanda praeter necessitatem").
In any case, there are some more or less robust neurophysiological correlations of mental
activities which provide a better understanding of these mental events (cf. I.). And a lession of
lesions is that there are necessary neuropysiological conditions for the whole range of (human)
expressions of mental events like seeing colors, remembering concepts or planning actions. These
are necessary conditions at least if one is not willing to subscribe to idealism or to the view that the
mind is still intact behind the stage of a damaged brain like an inaudible chatter behind a broken
loud-speaker.
Because pointing to NCC is not sufficient for a naturalistic theory of mind, philosophical
arguments are needed. Naturalism (sometimes - and somewhat misleadingly - also called
physicalism or materialism) requires at least a form of supervenience and a further condition.
Supervenience or a version of mind-brain identity theory alone is not sufficient.
An identity theory is not sufficient because it doesn't say what kind of ontological entity there is. If
mental states are (identical with) physical states, one could still subscribe to the variety of idealism,
ontologically reducing matter to mind via the identification and not vice versa. Even some
neurophilosophers from the camp of radical constructivism seem to get (perhaps not intentionally)
into the neighbourhood of solipsism which is a kind of idealism. An identity theory is also compatible
with neutral monism, ontologically reducing mind and matter to a third "substance", for example,
logos (Heraclitus), God (Baruch de Spinoza), elements (Ernst Mach), the absolute (Friedrich