In this selection from his book, Mind and the World Order, C.I. Lewis posits two components of experience. The first element consists of what Lewis calls “the immediate data,” by which he means the input that a person receives via her senses (187). This is the datum that is presented to the mind. The second element consists of “the form, construction, or interpretation” of the sense data, which is created in the process of thought. This is the mind’s interpretation of the datum. Otherwise put, the datum comes from outside the process of thought (although maybe not outside the mind) and serves as the raw material on which the process of thought works to come up with judgments.

Lewis says that although the way in which the datum/impression distinction is described varies significantly amongst theories of knowledge, it is nonetheless recognized by most of them. To deny this model, according to Lewis, would be to “betray obvious and fundamental characteristics of experience” (187). If there is no externally-based datum then knowledge is without content and it seems arbitrary. If there is no interpretation then there can be no knowledge, only sensory impressions of which the agent can make no sense (because she can not designate them in order to think about them.)

While the interpretation of an item can change relative to issues such as the desires or goals of the observer, the sense impression (“the given”) remains unchanged. Lewis offers the example of how one may describe a fountain pen in three different ways (which reflect three different mental characterizations or judgments of the object) depending on the issue (for lack of a better term) with which he is concerned. When he designates the thing as a “pen” it is a reflection of his desire to write. When he picks it out as a “cylinder” it is a reflection of his desire to explain a problem in geometry or mechanics. When he calls it “a poor buy” it reflects a present concern with his expenditures (188). Throughout it all, however, his sensory impression (for our purposes at least) can be said to stay the same. When he has a specific sensory experience of the pen and then interprets it as having been an experience of a “pen” he could have just as easily (had his interests been different) interpreted the sensory experience as one of “a poor buy” (188).

Lewis also describes sensory experience as “preanalytic data” (189). This characterization seems to suggest that Lewis takes sense data to be something a priori. However, he later asserts that “the given is in, not before, experience” (189). At this point in the chapter, exactly the given is becomes rather confused. Earlier on in the paper, Lewis speaks of “the given” and “the data of sense” as roughly synonymous. Here, however, he describes the given as the “abstracted element” and he questions whether or not it is “genuinely to be discovered in experience” (189). Furthermore, there is a technical distinction between any sense datum (or the set of sense data) and the given. Even by singling out a sense datum we have already engaged in an act of interpretation. According to Lewis, it is at least approximately correct to say that the only pure given could be the Bergsonian real duration or the stream of consciousness (190). Still, for the purpose of his argument, Lewis says that our interest should be in elements of givenness that we can, “for usual and commonplace reasons,” call experiences and objects (190).

Moore, like Lewis, affirms the existence of sense data. Their views have some striking similarities as well as important differences. Lewis says that “the empirical object, denoted by a concept, is never a momentarily given as such, but is some temporally-extended pattern of actual and possible existence” (186). For example, I have a sensory experience of Elliot (my cat.) This is the datum. I interpret the datum and classify what I perceive as “cat.” This is the interpretation. However, what Lewis wants to emphasize is that what is denoted by my concept cat is really a (please excuse my clumsy way of trying to describe this) series of instances of cat extended in time, [and causally connected to one-another (but I’m not sure whether or not Lewis wants to commit to this)]:

“cat”= Elliot TI, Elliot T2, Elliot T3….

By “actual and possible existence” Lewis means that the concept can describe a chain that combines temporal instances that have already occurred and future possible instances (I am just using minutes as “instances” for simplicity’s sake):

“cat”= Elliot T1(12:38am 10/24/05), Elliot T2 (12:39am 10/24/05)… Elliot TN (sometime in the future)…

This sounds very similar to Moore’s citation of Mill’s idea of material things as “permanent possibilities of sensation” (185). On this view, when I know a fact such as “This is part of the surface of a human hand” the sense datum is the principle subject of the fact. What I know with regard to the sense datum is “a whole set of hypothetical facts” or conditions that, if satisfied, will cause me to perceive a sense datum of this type (185). To put this colloquially, I know where to go for a sense impression of a hand.

For Lewis, sense data come from the “thick experience of the world of things” (189). When I look at my hand, for example, I receive a visual impression. Lewis seems to want to say that this visual impression is of my hand as an object. I do not just perceive the surface of my hand, but the hand itself (189). Here Moore disagrees. On Moore’s view, when I look at my right hand the datum that I perceive “is identical, not… with [my] whole right hand, but… with… part of its surface” (183).

-- AnnieS - 24 Oct 2005