An argument against essentialist modes of thinking

From Typecasting: On the Arts and Sciences of Human Inequality*:

Despite its aura of certitude, classification is never a neutral act. Naming is a form of exercising power, and the ways that things are named often reflect the outlook of the namer.

This makes me think of Foucault's The Order of Things which contains an anecdote that I think well illustrates how our seemingly neutral and sensible methods of classification really are sort of odd and arbitrary:

This passage quotes a "certain Chinese encyclopaedia" in which it is written that "animals are divided into: (a) belonging to the Emperor, (b) embalmed, (c) tame, (d) sucking pigs, (e) sirens, (f) fabulous, (g) stray dogs, (h) included in the present classification, (i) frenzied, (j) innumerable, (k) drawn with a very fine camel hair brush, (l) et cetera, (m) having just broken the water pitcher, (n) that from a long way off look like flies". In the wonderment of this taxonomy, the thing we apprehend in one great leap, the thing that, by means of the fable, is demonstrated as the exotic charm of another system of though, is the limitation of our own, the stark impossibility of thinking that.

Why can't we think that? Does it make any less sense than our own essentialist system of biological classification, which was invented in the 18th Century by a notable racist and based on the then-normal ideal of stratification?

If Lennaeus's method created a tool for modern science, it still used the metaphor of monarchy as a way of framing the order of things. Plants and animals constituted two natural kingdoms (regna naturae). Within these kingdoms, a hierarchy of classes, orders, genera, and species provided categories by which all life forms, plant and animal, were classified. In a world where many still saw hierarchy and inequality as natural, taxonomy provided a tangible ratification of this belief.
[...]
Not only did monarchy supply a defining imagery for understanding nature, but the Linnaean system also validated prevailing inequalities of gender... Even though many plants are hermaphroditic and do not conform to customary definitions of gender, Linnaeus emphatically described plants in terms of their male and female parts, with so-called dominant parts designated male, submissive parts female.

Interesting that this is the same basic system of taxonomy that we learn in school today.

Stephen Jay Gould (yay!) argues that this essentialist paradigm needs to be reexamined, not only because it is incorrect and misleading, but also because of its negative impact on our social organization - for instance the reemerging field of scientific racism (beloved of intellectual bedfellows SDA and IQ fetishist Richard Lynn among others - recently discussed here). He says "Nature comes to us as continua, not discrete objects with clear boundaries".

Essentialism establishes criteria for judgement and worth: individual objects that lie close to their essence are good; those that depart are bad, if not unreal... Antiessentialist thinking forces us to view the world differently. We must accept shadings and continua as fundamental...

The taxonomic essentialist scoops up a handful of fossil snails in a single species, tries to abstract an essence, and rates his snails by their match to this average. The antiessentialist sees something entirely different in his hand -- a range of irreducible variation defining the species, some variants more frequent than others, but all perfectly good snails.

We know what the previous outcomes were of scientific racism: the Atlantic slave trade, the Nazi's "final solution", South African apartheid... certainly these were not the most noble moments in our human history. So why are these theories rearing their ugly heads again?

*By the way, this is a fascinating book. There are several cheap copies at the fantastically huge BMV on Bloor St in Toronto - I got mine for only $4.99