Another point. Many criticisms (and rebuttals by Boorses) revolve around the idea that there is no such thing as a “species design” and a “species-typical functioning” because phenotipes change under evolutionary pressures.
Boorse’s rebuttal is first, (pp.28-41) to stress that people who see a difficulty in the variability of human species design miss the forest for the tree, or in other words, that evolutionary change is irrelevant, because it takes place at the wrong “order of magnitute” (37). Through non evolutionary times, human phenotypes are remarkably stable; if it were not so, standard anatomy textbooks would contain only lies.
Another, but related reply, is to say that these authors miss the distinction between adaptation and disease (41).
“Being black in Trondheim or white in the Sahara is neither a disease nor pathological, though each condition raises the risk of disease, as Engelhardt observes. His examples, far from being cases where maladaptation is disease, are instead clear cases of the contrast between health and adaptation” (41)
The point is further developed in the section “dynamic equilibrium and environmental disease”. Here Boorse’s point is that “organisms, including man, have evolved many adaptive mechanism to maintain normal physiology against environmental variation” (79). Therefore
“Some of this pattern is shown by Engelhardt’s Norwegian in Africa. White skin in Africa is not itself a disease. But if the Norwegian is transported suddenly and left in the equatorial sun, he will get at least a severe sunburn, which is pathological. However, if his level of sun exposure had changed gradually, his skin would have tanned, allowing him to stand much more sun without injury. To use HTC’s terminology (p.553), both his original white skin and his tan are intrinsically healthy; the tan is also instrumentally healthy in protecting him from injury. That is, neither tan nor lack of tan is disease, but the latter makes disease more likely in a certain environment” (80)
My impression concerning these passages is that Boorse is escaping the real problem. This I would put it in the following way:
Problem: the efficiency of a structure/process in accomplishing its function depends upon the environment where it operates. Let us now imagine a future in which people ceased to reproduce by usual means and employ only artificial insemination. Let us suppose, for the sake of the argument, that the practice gets culturally stable, and “natural” reproduction becomes a taboo. In this environment, erectile dysfunction does not detract from the goal of reproduction, as there is no goal to which the erection of the penis contributes. Let us also suppose that this practice lasts for a sufficiently large number of year, sufficient to counterbalance the millions of year during which humans reproduced in the traditional way, so that artificial insemination counts by the numbers as statistical normality with respect to reproduction. When this scenario will becomestrue (as in many science fiction novels) the BST must say (at that point in time) that erectile dysfunction is not a disease, in that it does not detract from the typical (species normal) efficiency of erection. (On the interpretation of “typical efficiency”, see the previous post). For at this point, the typical efficiency of erection is null, as erection plays no role in the (statistically speaking) normal environment.
Notice a further oddity, the worse of all: suppose that after eons in which humans reproduced only through non-natural means, old-fashioned sex becomes suddenly (let’s imagine, by violent cultural revolution) the rule again. At that point in time, the BST would still treat people with erectile dysfunctions as healthy.
This odd feature results from a necessary feature of the theory: in order to avoid the relativization of “efficiency” to the specific envirnoment in which the organism operates (which Boorse conceptualizes as “adaptation”), Boorse must average out spatially and temporally over the whole natural history of the species homo sapiens. It cannot be further amended.
This result counts as a reductio ab adsurdum of the theory. Or doesn’t it? And I haven’t still found a cogent rebuttal by Boorse. Am I missing something?