P. 18 lexical ambiguity in the explanation of the environmental clause
“Betchel (like HTC) goes on to note that the above idea makes universal diseases impossible, and that I proposed an environmental clause to handle this problem. He quotes my disjunctive summary from DI and complains. […] As for a “hostile” environment, it is one that disrupts something in the hierarchy of statistically normal species-normal part-functions, i.e., reduces a part’s typical contribution to a physiological goal (see Specific Terms) – that is the “state,” as explained in WF and HTC. “
The expression “a part’s typical contribution to a physiological goal” is ambiguous between:
A. typical (=species-normal) in the type of contribution
B. typical (=species-normal) in the degree of contribution
if A, then a hostile environment is one which reduces the efficiency of a structure/process (relative to its typical/species-normal function), simpliciter
if B, then a hostile environment is one which reduces the efficiency of a structure/process (relative to its typical/species-normal function) in comparison to the typical (species-normal) efficency. What’s weird is that what Boorse says makes no sense to me on either reading (am I failing to understand something?).
Let me explain:
Suppose that A. Then for any structure/process in any given environment x1, one can imagine a further environment x2 where the same structure/process performs its function with an increased efficiency . For example, suppose that in our present circumstances, a given amount of collagens (the stuff which keeps bones resistant) is produced, at age 70, by the bone cells. We can imagine an environment which includes medical technologies (e.g. drugs) which stimulate the cells of 70 year old people to produce more collagenes, which would increase he efficiency of those cells. Since in this interpretation the theory counts as disease the decreased efficiency of a biological function relative to any conceivable standard, the theory would entail that 70-year old people that by present medical standards are perfectly healthy are indeed unhealthy. This amounts to a counterexample to Boorse’s theory
Suppose that B. Take the case of a universal disease: caries. If a hostile environment is one that reduces the efficiency of a structure in comparison to typical efficiency, then caries is not due to a hostile environment, because the typical efficiency of teeth surface is compatible with getting caries sooner or later. Under the interpretation B, the environmental cannot help solving the problem of universal diseases.