grover maxwell

the ontological status of theoretical entities

referat by kate brubacher

 

 

I. Maxwell begins by outlining what he considers ludicrous claims, being completely out of line with science and rational attitudes.

    1. Entities referred to by scientific theories are merely convenient fictions
    2. Talk about such entities is translatable without talk about sense objects or everyday physical objects
    3. Talk about such entities should be regarded as only a calculating device without any cognitive content

In agreement with Professor Ernest Nagel, Maxwell quotes him as saying, "The opposition between [the realist and the instrumentalist] view [of theories] is a conflict over preferred modes of speech." (348)

Maxwell sets out to propose constructive arguments and to critically examine some of the assumptions that have caused problems in the area of Realism vs. Instrumentalism.

II. Maxwell tells a story of science fiction.

In the days before microscopes there lived a scientist by the name of Jones. He noticed that diseases were spread through human contact, or contact through objects. He knew that some diseases were spread through visible modes (such as body lice), so he assumed that all diseases were spread through the same means – only some "bugs" were too small to be observed. He called these bugs that spread disease, "crobes."

Based on Jones’ assumptions, he suggested methods for preventing the spread of disease. These methods were accepted and the death rate declined by 40% in ten years. Obviously the philosophers had problems with Jones’ illogical jumps. The main argument was, "In order to account for the facts, Jones must assume that his crobes are too small to be seen. Thus the very postulates of his theory preclude their being observed; they are unobservable in principle." This logical fallacy was indeed valid.

The conclusion of the story is that Jones lived to see the invention of the microscope. He was then able to observe his crobes, and prove that he was correct. Some philosophers admitted they had been incorrect (although few, I assume). Others developed new contentions or modified forms of their original arguments.

III. Two arguments rising out of the story.

    1. Some philosophers said that Jones’ crobes were never unobservable in principle.
    2. Another contention arose that Jones’ crobes were never really observed. Only shadows and images were seen – nothing corporeal.

IV. Maxwell address III-B.

A. He takes us from this anti-realist claim (that the crobes were never seen, merely shadows and images) and draws out the implications of a full embracement of such a belief. When is something observable? If we can only observe with the naked eye, then we cannot see physical things through glasses, windows, microscopes, or telescopes. Maxwell points out "distortions due to temperature gradients" which are constantly present. How is it that we should say that a person who needs the aid of spectacles only sees shadows and images while those of us without glasses can directly observe our world? Maxwell gives a series: looking through a windowpane, looking through glasses, looking through binoculars, looking through a low-power microscope, looking through a high-power microscope, etc. Now the question is where would we be able to draw a line between an "observation" and a "theory"? In some cases that line can be drawn, but not consistently. So if there is no objective line, it doesn’t really do any good. Things cannot slip in and out of "real thinghood."

B. Interesting example of "punching eyeball." What do you see?

V. Maxwell addresses III-A.

This is the claim that "it is only those entities which are in principle impossible to observe that present special problems" (351). After settling on a generally accepted definition of "impossible" (the theory itself entails that such entities are unobservable), Maxwell shows that this contention precludes itself. He gives an example:

Working under this supposition, suppose you wanted to determine whether ‘electron’ was a theoretical term. "One must first see if the theory entails the sentence ‘Electrons are unobservable.’ "Indeed electrons are unobservable. But what about the "sentence" itself? What if ‘electron’ is an observation term? Then the sentence would assert that electrons are unobservable. But in order for it to be unobservable, ‘electron’ cannot be an observation term. So if it is, it isn’t. If ‘electron’ is an observation term, then it is not an observation term. So now our original sentence, ‘electrons are unobservable,’ is merely meaningless sounds and marks because it asserts nothing (352).

Since he followed that thread to completion, Maxwell turns around and works under the assumption that "well-formed theoretical expressions are genuine sentences" (352) and goes onto talk about unobservability in principle. He equates electrons with Jones’ crobes. He proposes that at some point we will be able to observe electrons, even if not directly. So electron could possibly be observable, even thought at this point it is unobservable. Maxwell goes on to say that any term is a possible term for an observation term. We have no idea what future breakthroughs and inventions will bring us.

Another attempt at drawing a line between theoretical and observable is to change the tense of the word. Thus it would not be whether something is ‘observable,’ but rather ‘observed.’ Maxwell points out that his Aunt Mamie in California who he has never seen, would then become theoretical, and snow would be theoretical to Floridians who had never seen it. But snow and Aunt Mamie would certainly still exist. This attempted line between observational and theoretical has no affect on the ontological status of Aunt Mamie or snow.

VI. Maxwell has proved [attempted?] that there is no definite line between the observable and unobservable. He acknowledges the import of an ‘observation base.’

A. We do need an observation base as a confirmation device.

B. ‘Observation term’ becomes ‘descriptive term’ and ‘observation sentence’ becomes ‘sentence whose only descriptive terms are observation terms’ (353).

VII. Observing the theoretical.

    1. Mawell points out that there are instruments which enable us to do this.
    2. We also observe the theoretical with "our painfully acquired theoretical knowledge" (such as that of gravity).

 

VIII. Conclusion

Any line between theoretical and observational is purely accidental and holds no validity. A line could only be based on personal factors – nothing universal or shared. The difference between observation and theory is insignificant as it has no affect on the ontological status of the entities divided.