Race, as a biological phenomenon, does not exist -- so says standard academic leftist doctrine. In support of this, leftists cite the fact that races & ethnic groups are fuzzy rather than clearly-bounded categories; a single person may possess ancestry of two or more groups, and likewise there are geographical regions whose populations contain racial mixtures or phenotypes intermediate between two adjoining groups. Some genes vary gradually along a geographic vector, known as a "cline". There are a number of genes that all homo sapiens share in common, indeed the great majority; these genes & their corresponding traits are taken as evidence of an essential & universal human nature, and the differences, which reflect adaptations to local environments, are regarded as inconsequential. Race exists at different levels of scale: there are the five major continental races, plus numerous subraces, ethnic groups, & individual tribes. The popular idea of racial identity is also ambiguous..A person's racial ancestry may not be obvious from her or his external appearance, and socially-constructed labels can be based on arbitrary standards which do not accurately reflect DNA evidence. For all these reasons, leftist academicians assert, there is no such thing as race.
However, leftists believe in something else called "culture". Indeed, culture is thought to be a very important, powerful & deterministic influence. Strangely enough, though, culture, as a phenomenon, has many things in common with race. Like races, cultures have no firm or absolute boundaries. A single person can belong to two or more cultural groups at the same time (and can even switch affiliation over the course of a lifetime, which is not possible with genetic race.) Just as genes can be traded between races, so do cultures exchange memes, patterns of learned information such as customs, language & arts. A given cultural practice or artifact can be spread over a wide geographical area and across multiple culture groups. Some anthropologists believe there are cultural universals, such as language, religion & marriage customs, found ubiquitously in all human groups but expressed differently in particular circumstances. Like races, two or more cultures can blend together over time, or one can fragment into many. And, as with races, the vernacular distinctions between cultures are socially constructed & ambiguous. Cultural groups often have arbitrary & superficial standards, such as fashion, for determining who is "in" or "out". Yet, despite all these loose, messy, fuzzy qualities, culture is not only very real, it is held by most leftists (except those who are economic determinists) to be a central force in human life & history.
Another thing which some leftists, particularly those of an extreme collectivist or postmodern bent, assert does not exist is the individual self. We may see human bodies walking around, but even though they appear to move independently, they aren't really individuals. The reasons are as follows: What we call the 'self' is found, on examination, to be composed of a ever-changing stream of subjective contents: states of consciousness, thoughts, feelings, perceptions, & the like. There is no single, unified centre sitting like a rock in the midst of this ocean of flux, no Neoplatonic monad. The mutability of inner consciousness is mirrored by the chaotic, constantly-changing patterns of neuronal activation found in brain scans. The brain, in fact, is a parallel-processing system, in which multiple parts function simultaneously & quasi-independently, & different processes can even contradict each other, as has been found in split-brain research. Moreover, the boundary between self & other, or subject & object, is ambiguous & arbitrary: it can shift with alterations in the state of consciousness, like dreams, meditation or the influence of drugs. There is no discrete, absolute point where "I" end and "not-I" begins; the definition of self, at least on the conscious level, is relative to what is defined as Other.
Therefore, because the self is complex, changeable, nondiscrete & pluralistic, rather than a unitary, immutable lump like the pre-modern-physics model of the atom, it is a mere illusion, with no valid claim to existence or recognition, and can safely be ignored -- in favor of a socialistic concern with the good of Society.
If, however, we turn to look at that same Society, something rather puzzling emerges. For societies are, in many ways, very much like individual selves. Just as a constant stream of contents flows through the individual consciousness, so, on the larger scale, do individual people move through social groups. New members enter a society through birth or immigration, others leave through death or emigration, & there is a complete turnover of populace every generation. Just as an individual retains her subjective sense of identity through changing states & experiences, so does a society retain its form -- though never perfectly -- even while the members that compose it change. Just as an individual self is composed of various parts (subpersonalities, archetypes, aspects, neural modules, etc.), so does a society contain numerous subgroups, subcultures & factions, which often compete amongst themselves for dominance. Just as the boundaries of the self are ambiguous, so are those of the society. Two or more societies can easily overlap with each other; it is not always clear who belongs to what group, and officially-declared boundaries, such as national borders, are often under dispute. Yet, all this change & ambiguity is no threat to the validity of society as a meaningful concept. Indeed, some leftist writers are quick to celebrate the postmodern fluidity of the new social order.
I call this the argument of nonexistence from complexity. This is a rhetorical strategy which implicitly invokes the commonsense notion of an entity as a simple, clear-cut unit, points out how the subject in question diverges from that naive model, and asserts that, because something is not as simple as one might naively think, it therefore does not exist at all. Since most things in the natural & social world are less ideally simple than Platonic solids, this strategy has, potentially, unlimited applications. In actual practice, however, its use in leftist academia is highly selective, politically motivated & disingenuous. Only things which leftists think ought not to exist, like race & individual consciousness, tend to get complexified out of existence.
I have rarely seen this argument applied in the opposite direction by anti-socialists. Perhaps the nearest case would be Max Stirner, who declared that all social, cultural & political institutions are "nothing to me". Yet few even among extreme egoists would deny that social phenomena exist at all.
One phenomenon whose existence no one, not even the most radical leftist, would try to deny is the weather. Anyone who ignores the weather will end up getting wet -- literally. But the weather, judged by academic leftist standards, is very politically incorrect. It is constantly changing, & can never be predicted with complete accuracy. Weather patterns cross geographical & socially-constructed borders with sublime nonchalance. Moreover, weather phenomena are nondiscrete & nonbounded in nature. For instance, take a hurricane (please). There is no specific time or place at which a hurricane can absolutely be said to begin or end; although the Weather Bureau uses arbitrary standards to determine the official extent of a hurricane, it just might as well be said to have begun with the proverbial flap of a butterfly's wing in some distant region. Yet, a hurricane can have quite an impact (no pun intended).
The shapes of all these things can be described in terms like fractals, chaos, fuzzy logic, dynamic systems, networks, etc. All of these are part of the new math & science which emerged toward the end of the last century. Only very recently in history have researchers had the computational power to study such complex structures & processes.The reason that the nonexistence from complexity argument is so persuasive is that this way of thinking is mainly still unfamiliar to us. Simple, discrete forms seem more plausible. Human beings seem to be neurally wired to parse reality into chunky little bits. We tend to think in integers, not because integers are necessarily more real or valid than other expressions of quantity, but, probably, because our early ancestors had to count on their fingers & toes.1
Around the same time as these new advances in the hard sciences, the literary & cultural movement known as posmodernism began, from its own perspective(s), to explore the kaleidoscopic vistas of a shifting, fluid world. At its worst, postmodern discourse is fuzzy thinking in the illogical rather than logical sense; it becomes an endless series of exercises in complaining about how things are too complicated to say anything substantial about them. At its best, however, it can be a tool for thinking about things that are fractal-like, chaotic, dynamic, sprawling, multiplistic, nondiscrete, fragmentary & liminal; a verbal, conceptual, qualitative tool to complement the quantitative tools of mathematics & science. To fully develop this resource, postmodern theory must first be pried free of the stranglehold of leftist dogma & opened up to a wider range of political views. Next, it must be harmonized with the disciplines of science, mathematics, & statistics, so that the qualitative & quantitative approaches can productively cross-fertilize.
The 21st century requires the ability to think like a fractal. As we learn to put on this odd-shaped new thinking cap, there will be some surprises: we may discover that race is as nondiscretely real as culture & society; that the inner & outer worlds are equally fluid, flexible & frangible; & that the individual self is as intricately chaotic & dynamic as a hurricane.
1. The morpheme "tik", meaning both "finger" & the number "one", is believed by the phylogenetic linguist Joseph H. Greenberg to come from the oldest ancestral human language. Cognates of it can be found all over the world, from the English "digit" to the Eskimo-Aleut Greenlandic "tikiq". (Nicholas Wade, Before the Dawn: Recovering the Lost History of Our Ancestors, pp. 230-2.)