l not considered bald. The rest only differs by degree. A vague predicate is said to be usable when it has clear cases and counter-cases. Van Fraassen believes that there is a true counter-case to observable terms. He uses an example of charged particle in a saturated environment. The charged particles path is marked by droplets on the ions. A jet’s vapor trail looks similar to this. How are we to distinguish between the two examples that look alike? Maxwell also attempts to say that everything could be observable at some time. He believes that something is never unobservable because at any time something could happen to make it observable, for example electron-microscope eyes. Van Fraassen combats this argument by saying that the human organism is basically a measuring apparatus. Humans have certain limitations that will keep them from doing certain things. He states that, “It is these limitations to which the ‘able’ in ‘observable’ refers – our limitations, qua human beings. (271)”•Anti-Realist Argument from Underdetermination1.Only believe one theory T is true, over another theory T*, if you have more evidence for the truth of T than T*.2.The only evidence we have to support the truth of theories based on theoretical terms are observations.3.Our observations underdetermine which theory based on theoretical terms is true.C.We should never believe any theory based on theoretical terms is true.Van Fraassen questions whether we should believe that our theories about unobservables are true because of the Argument from Underdetermination. The anti-realist believes that the only way to support the truth of theories based on theoretical terms are observations. If two differing theories based on the same observations lead to different theoretical terms, the observations underdetermine which theory based on theoretical terms is true. Which theoretical term is true if...
