Smart's "Sensation and Brain Processes"
In Smart’s view, the main reason against the view that a sensation can be a brain process is that “qualities of sensation are something over and above the qualities of brain processes” (Smart 1959, p. 59). Even if a mental event is identical to a brain event, this single event has not only material properties but also mental properties as well. Smart writes, an objector may say “it may be possible to get out of asserting the existence of irreducibly psychic processes, but not out of asserting the existence of irreducibly psychic properties” (Smart 1959, p. 59). The identity of mental events with physical events will not be sufficient to prove the identity thesis correct, for the psychological properties of such events could not be treated in terms of the physical sciences. Mental events, then, must have peculiarly mental properties. If mental events do not have some sort of mental properties, then how could someone pick out and describe such events as mental? If sensations are strictly identical to brain processes, then it is possible to identify sensations in two ways. On the one hand, sensations can be thought of in terms of their psychological features, and, on the other hand, when we think of sensations as brain events they can also be thought of in terms of their physical features. Therefore, there are certain mental properties not captured by mental and physical processes (Smart 1959, pp. 59-60).
Smart considers other objections, but he has the “least confidence of having satisfactorily met” this objection (Smart 1959, p. 59n). In “Sensations and Brain Processes: A Reply to J.J.C. Smart,” J.T. Stevenson (1960) attempts to clarify the above objection. He distinguishes between two sorts of properties, M-properties and P-properties. “M-properties are those properties which the materialist wishes to allow in his physicalistic scheme,” while “P-properties are those defining properties for “sensation” which prevent us from defining “sensation” in terms of M-properties” (Smart 1959, p. 507). Stevenson argues, and I agree, that since, according to Smart, P-properties cannot be reduced to M-properties and “sensations” cannot be synonymous with M-properties, a consequence of Smart’s theory is that “a brain process has P-properties iff it has certain M-properties” (Smart 1959, p. 508). This is still a contingent matter of fact discoverable by empirical investigation. To state this relation is just like a psychophysical law relating sensations to brain processes; however, in this case, we deal with properties of sensations rather than sensations themselves. Therefore, Smart does not avoid promulgating psychophysical laws; instead, he offers one. In “Further Remarks on Sensations and Brain Processes,” Smart (1961) summarily dismisses Stevenson’s idea that there are mentalproperties.
Smart answers this objection by saying that when we describe events as mental, the properties are neither peculiarly physical nor incompatible with being physical. In other words, the words used to describe such properties are quasi-logical or topic-neutral. Smart writes, “When a person says, ‘I see a yellowish-orange after-image,’ he is saying something like this: ‘There is something going on which is like what is going on when I have my eyes open, am awake, and there is an orange illuminated in good light in front of me, that is, when I really see orange’… Notice that the italicized words… are all quasi-logical or topic-neutral” (Smart 1959, p. 60). What does it mean for the words used to be quasi-logical or topic-neutral? To identify an event as psychological there is some similarity the event has to certain other events. We specify these other events only by reference to what causes them. According to Smart, we say nothing about why the similarity holds. For example, when I say that I have a sensation of blue, Smart believes that means nothing more than something is going on like what goes on when I see something blue. Smart believes this is merely a description of my having a sensation of blue only as an event which is similar to the event of my seeing blue. The event of my seeing blue is caused by certain standard circumstances by stimulations from blue objects. Thus, the description of mental properties are topic-neutral.
The above represents Smart’s answer in his article, “Sensations and Brain Processes.” I mentioned earlier that Smart modifies his original argument against objection 3 in “Further Remarks on Sensations and Brain Processes.” In that brief article, Smart explains that “although sensation reports are not materialistic statements, they are not immaterialistic” (Smart 1961, p. 407). He exemplifies this statement with an analogy. The analogy goes something like this: the nontranslatability of sensation statements into brain processes is similar to the way in which “someone telephoned” cannot be translated into “the doctor telephoned,” even though the doctor did call. Sensation statements are not materialistic just as “someone telephoned” is not a medical statement. The fact remains that the doctor telephoned, and this, according to Smart, is a medical fact. Smart says, “Although “someone telephoned” is not a medical statement, it is not a nonmedical statement” (Smart 1961, p. 407). In both instances, the descriptions are topic-neutral.