Causation of Sense Data

The argument from causation was supposed to show that there must be something other than sense data, "behind them." The basic idea is that every event, including events of awareness of sense data, must have a cause, and that sense data cannot cause anything, and so there must be something else in the world.

Such a claim makes sense from the perspective engendered by the argument from illusion, which takes it to be a matter of fact that we are aware only of sense data, never of material objects. One needs a way to add the material objects back. However, if sense-datum language is nothing more than a language, not in contradiction to ordinary talk of material objects, but just an alternative to such talk convenient for certain purposes, we must be able to translate causal talk into the language (otherwise there is an empirical difference between the two languages: one allows causation, the other doesn't).

The argument has two parts:

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Ayer has already shown that that is "a not very probable statement of fact," and that the corresponding heuristic maxim, "it is always worth looking for a cause," which may well be true, is of no use for the argument from causation.

So Ayer has already pulled the rug out from under the argument.

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Even though the argument has already been defeated, Ayer still needs to refute the claim made in the second part of the argument, since he needs to show that there is no empirical difference between material object language and sense-datum language, and that would be false if causal talk couldn't be re-expressed in sense-datum language, that is, if the empirical phenomena that lead us to endorse causal talk cannot be reported in sense-datum language.

It is important for Ayer's purpose that causation involves nothing more than association of events, perhaps according to postulated laws, that there is no necessity or internal animation necessary or even possible. One might think that the fire through some internal activity brings about the blister, but all we see that leads us to postulate the association is the correlation. Ayer claims that causal connections are always, as a matter of necessity involving the notion of causation, observable connections. Since they are observable, they are reportable as associations of sense data. Far from leading us to postulate occult (that is, hidden) entities, causation cannot involve occult entities. So far as I can see, Ayer has no argument for the claim, though he does establish all he actually needs, namely that the associations of observable events, of sense data, can be causal.

Ayer's claim that causal connections are always observable connections seems to contradict the familiar scientific idea that there are all sorts of hidden mechanisms involving electric charges, subatomic particles, complicated enzymes, …. Eddington is most famous for discussing the idea of an occult scientific reality behind our ordinary perceptions (222). Of course, there is a parallel theological version. But, and since this is such a persistent and widespread misconception, this is worth understanding quite independently of any theory of perception. The reason we believe in the electric charges, etc., is that under appropriate circumstances, we can observe them. It isn't that there are "two worlds," there are just varying conditions of observation.

When leading someone to touch an object in a nearly room, one might say, it looks black, but it is really blue. What does "really" mean here? Well, it means something like, under better or more standard conditions for observing color, it would look blue. Similarly with, "the table is really made of electrons, protons, …." Eddington appears to have been confused by the fact that the appropriate conditions for determining whether something is really made of atoms are completely different from the appropriate conditions for determining whether something is really a table. If one misconceives "really" as talking about a single kind of thing, it looks like there appear to be two "realities," but that is confused. Note that both kinds of observations are observations, and hence reportable in terms of sense data. The theological case of causation is not, in this respect, generally held to be analogous, but, as we have seen, that just renders the corresponding causal talk inappropriate and useless.

One of the reasons the causal argument looks plausible, is that we have the idea that there are hidden things involving electrical effects, chemical effects, and so forth going on all the time that underlie the processes we see, and so they must be in some fundamental sense "more real," or more fundamental or something like that. Well, they are there, but in the same sense in what we ordinarily take account of is there.

So, back to our argument: any empirically observable correlations that can be described in material object language, perhaps by talking about causes, can equally well be described as correlations of sense data and expectations about sense data. Price argues that a magnet in your pocket cannot be explained in terms of sense data, since it isn't perceived. But the way you might expect that it is there in material object language—say, compasses in the vicinity are going crazy—can perfectly well be redescribed in terms of sense data.

-- ShaughanLavine - 10 March 2003 - 20 Mar 2007 - 23 Mar 2007