Pragmatic Approach to Laws

In her essay “Pragmatic Laws”, Mitchell rejects the normative and paradigmatic approach to laws. As she said, she is not going to define what law is, but to discuss the “understanding” of the usage of generalization in science. Firstly, Mitchell discusses about the traditional view of laws, the normative approach. In normative approach, scientists need to find or create strict laws that can be applied generally. By inputting different initial conditions, these laws will generate specific outcomes that meet the phenomena of natural world. If people cannot find such laws in biology, then it means there are no laws in biology. The normative approach ignores the degree of contingency. Mitchell argues that many laws, especially biology laws, do not have clear distinction between university and contingency. Next, Mitchell discusses the paradigmatic approach. In this approach, scientist will compare the generalization in biology with the laws in physic or other science to see if there is a match. If the generalizations in biology are like the law in other science, then there are laws in biology. The paradigmatic approach fail to define laws in some “unsystematize space” where no physical laws can be referred.

What is a “Law”?

According to Hung, the law of nature should be universally true and both informative (empirical) and necessary. The initial requirements are both “universality” and “truth” (133). To be a law, a statement at least should be true. If the statement is wrong, such as “earth is cube shape”, then it is not a law whatsoever. Universality means a law should be applicable “throughout time and space” (133). For example, “The tree in my backyard is an oak” is not a law.

“Species are nature’s only objective taxonomic units”

Gould thinks that species are objective. He says populations do “branch from their ancestors, evolving, interbreeding and “maintain common ecological niche” (20).  In addition, there is strong evidence to show that species are “mental abstractions embedded in culture practice or packages in nature” (20). Gould gives examples of the classification method of organisms by people from other cultures, including New Guinea and Tzeltal. These “folk taxonomies” (20) show striking consistency with our more “scientific” Linnaean catalog. Thus, he argued that nature really is divided into discrete species. Gould claimed that most of the time, species stay in steady lineage. Evolution is rather a “rapid transition” than “slow transformation” (26). Our nature is more likely to be “structure and legitimate distinction”. He points out that “species are the units of nature’s morphology” (26).

Breeding populations as “biological individuals”

In order to define species as individuals, Sober takes the first step to argue that breeding populations are “biological individuals”. By this he means, breeding populations, “a set of local demes linked to each other by reproductive ties but not so linked to demes outside the set” (156), can be defined as individuals.