Sorting Things Out (1999) by Geoffrey C. Bowker and Susan Leigh Star is about classification and its practical, social, political, and ethical consequences.

To classify is human. (1)

We all spend large parts of our days doing classification work. (1)

Each standard and each category valorizes some point of view and silences another. This is not an inherently bad thing — indeed it is inescapable. But it is an ethical choice, and as such it is dangerous — not bad, but dangerous. (5)

For any individual, group or situation, classifications and standards give advantage or they give suffering. (6)

Every link in hypertext creates a category. (7)

We define boundary objects as those objects that both inhabit several communities of practice and satisfy the informational requirements of each of them. (16)

An Aristotelian classification works according to a set of binary characteristics that the object being classified either presents or does not present. (62)

Prototype theory proposes that we have a broad picture in our minds of what a chair is; and we extend this picture by metaphor and analogy when trying to decide if any given thing that we are sitting on counts. (62)

Classification systems in general inherit contradictory motives in the circumstances of their creation. (66)

The ICD (International Classification of Diseases) can also be read as a kind of treaty, a bloodless set of numbers obscuring the behind-the-scenes battles informing its creation. This dryness itself contains an implicit authority, appearing to rise above uncertainty, power struggles, and the impermanence of the compromises. (66)

The great virologist Lwoff declaimed in 1953 that, “viruses should be considered as viruses because viruses are viruses.” (95)

It is a hard job to boil down a complex series of conditions to a single cause of death. (102)

The goal of the classification system is not to describe complex phenomenologies, but to prevent death. (102)

Medical classification systems are “naturally” prototypical; they nevertheless have to appear Aristotelian to bear the bureaucratic burden. (106)

Large modern states have found themselves forced into developing complex classification systems to promote their political and economic smooth functioning. (111)

A simple agonistic reading of the ICD is that the system was set up in an age of imperialism and helped impose an imperialist reading of disease from the West onto the rest of the world. (115)

There is no foretelling what information will be relevant. (116)

There is no such thing as a natural or universal classification system. (131)

Classifications that appear natural, eloquent, and homogenous within a given human context appear forced and heterogeneous outside of that context. (131)

Working infrastructures like classification systems are deeply embedded both in practice and in technology. (133)

List making has frequently been seen as one of the foundational activities of advanced human society. (137)

The production of lists (of languages, races, the minerals, and animals) revolutionized science in the nineteenth century. (137)

The list is both a hierarchical ordering and a practical tool for organizing work and the division of labor. (137)

The material culture of bureaucracy and empire is not found in pomp and circumstance, nor even in the first instance at the point of a gun, but rather at the point of a list. (137)

Garbage categories include an array of categories where things get put that you do not know what to do with — the ubiquitous “other.” (149)

In the face of incompatible information or data structures among users or among those specifying the system, attempts to create unitary knowledge categories are futile. Rather, parallel or multiple representational forms are required. (159)

Biologists are often classed as lumpers versus splitters. (159)

Lumpers tend to identify fewer species, lumping together specimens with fine-grained distinctions, and conversely with splitters. (160)

The further away one stands from the disease of tuberculosis, the more it appears to be a single, uniform phenomenon. (165)

The racial classification that was so structured in the 1950s [in South Africa] sought to divide people into four basic groups: Europeans, Asiatics, persons of mixed race or coloured, and [black] “natives.” (197)

“Separate development” was the euphemism used by the Nationalist party to justify the apartheid system. It argued from a loose eugenic basis that each race must develop separately along its natural pathway, and that race mingling was unnatural. This ideology was presented in state-sanctioned media as a common-sense policy. (197)

For apartheid to function at this level of detail, people had to be unambiguously categorizable by race. (201)

Both the scientific theories about race and the street sense of terms were confused. Prototypical and Aristotelian senses of categorization were used simultaneously. (201)

The conflation of Aristotelian and prototypical categories for race classification has deep historical roots in South Africa and elsewhere. The concept of racial types took firm hold in the nineteenth century across a range of natural and social sciences, and it was embraced by the architects of apartheid. At the same time, the pure types existed nowhere, and racism existed everywhere. (202)

Oddly, at times the multiple, contradictory methods of classifying could be used subversively to work in favor of the individual who lived between the categories. (203)

Apart from the categories themselves, the technology associated with the reclassification process was crude. Combs were sometimes used to test how curly a person’s hair was. (210)

Folk theories about race abounded; differences in cheekbones, even the notion that blacks have softer earlobes than whites, were taken seriously. (210)

The “pencil test” was recounted by many who had undergone the reclassification ordeal. (210)

They sticks a pencil in your hair and you has to bend down, and if your hair holds the pencil, that shows it’s too woolly, too thick. You can’t be Coloured with woolly hair like that. You got to stay black, you see. (212)

The more rigid the system of racial segregation and inequity, the more important passing became to those living in the categorical borderlands. (216)

A classification system can be used to remember all (and only that) which is relevant. (276)

Classification systems provide both a warrant and a tool for forgetting. (277)

Erasure is a key dimension of classification work in all organizations. (279)

The category of hysteria was naturalized in medicine and in popular culture at the end of the nineteenth century. People used the diagnosis of hysteria for purposes of social control as well as for medical treatment. (298)

The point is not who believed what when but rather that the category itself became a [boundary object] existing in both communities. (298)

A monster occurs when an object refuses to be naturalized. (304)

Borderlands are the naturalized home of those monsters known as cyborgs. (304)

A person realizes that they do not belong when what appears like an anomaly to them seems natural for everyone else. (304)

Monsters and freaks are also ways of speaking about the constraints of the classifying and (often) dichotomizing imagination. (304)

Monsters were understood, in the first instance, as exceptions to or violations of natural law. (305)

Monsters were united not so much by physical deformity or eccentricity as by their common inability to fit or be fitted into the category of the ordinary. (305)

Similarity is an institution. (312)

Classifications are powerful technologies. Embedded in working infrastructures they become relatively invisible without losing any of that power. (319)

Everyday categories are precisely those that have disappeared into infrastructure, into habit, into the taken for granted. (319)

The moral questions arise when the categories of the powerful become taken for granted; when policy decisions are layered into inaccessible technological structures; when one group’s visibility comes at the expense of another’s suffering. (320)

The task of the philosopher is to keep open and explore the spaces that otherwise would be left dark and unvisited because of their very success. (321)

We need to consistently explore what is left dark by our current classifications. (321)

No classification system can reflect either the social or the natural world fully accurately. (323)

Classification schemes always represent multiple constituencies. They can do so most effectively through the incorporation of ambiguity — leaving certain terms open for multiple definitions across different social worlds: they are in this sense boundary objects. (324)

We are taking a series of increasingly irreversible steps toward a given set of highly limited and problematic descriptions of what the world is and how we are in the world. (326)

The only good classification is a living classification. (326)

Book Notes

With respect to racial classification, the one-drop rule was in effect in the United States until 1967. And, with respect to gender identity, the U.S. Supreme Court issued a decision in 2025 that new passports must show a person’s sex assigned at birth, rather than their gender identity (with the X gender marker to be replaced upon renewal). Battles over the categories of birthright citizenship and naturalized citizen are ongoing.

Clearly, in an era where AI is increasingly used for categorization (e.g., enemies, guns), it’s never been more important to call attention to classification and its consequences.

As I work on Natural Information Architecture, I’m sharing notes and quotes from my sources of inspiration and provocation. As always, your questions and suggestions are welcome.