Licia Carlson's The Faces of Intellectual Disability: Philosophical Reflections breaks new ground in disability studies, bioethics, philosophy, cultural studies, and social justice studies generally. Carlson is advancing at least a dozen conversations, making connections amongst people quite unlikely to read each other. She jars even politically aware and critical-disabilities-studies-aware people out of naturalized notions of intellectual disability. The Faces of Intellectual Disability critically analyzes how the very categories of intellectual disability and the webs of social practices around people associated with such categories have been historically produced.

In the general public, as well as literature, philosophy, bioethics, policy discussions, and other areas, people with intellectual disabilities are often treated as a distinct kind, as if they are a consistent category, easily identified by specific, definite, and quantifiable features. They are often assumed to be unproblematic "natural kinds" —to use the philosophical terminology, and they are often assumed to have low or non-existent quality of life. They are often framed as less than human. Philosophical arguments about their rights (or, more often, lack thereof) often begin with such assumptions, making no attempt to connect with the concrete realities of actual people with intellectual disabilities or those who are directly acquainted with them. In fact, the voices of people with intellectual disabilities and those associated with them are often discounted, framed as lacking in epistemic authority, as sentimental or overly subjective. Carlson uncovers myriad ways that societies have produced various categories as "imbecile," "moron," "the retarded," etc., and have used such categories for their own purposes—exploiting, marginalizing, excluding, torturing, and generally de-humanizing people seen as lacking in cognitive abilities or development.

Carlson argues that categories such as "mental retardation" have often been unstable (93-96). Following linguist George Lakoff (who follows Eleanor Rosch), these categories have had "prototype effects" (96-98), through which certain representations of the given category are seen as more distinctive of the group as a whole than other representations. So, when at times society treated mental retardation as "incurable" and sought to isolate and warehouse those deemed retarded, it has projected that image onto all people with intellectual disabilities, regardless of the great diversity and particularities of their abilities, impairments, functioning, and lives. Carlson indicates various ways that power relations structure such categories and the social practices woven through them (99-101). She traces how people with intellectual disabilities have been constituted in relation to those considered "normal" as various faces: faces of authority, "the beast," suffering, and the mirror.

Carlson notes that people with intellectual disabilities tend to be framed as objects of knowledge rather than subjects of knowledge (15). In addition, she points out that people with intellectual disabilities are generally absent from philosophical discussion, except when philosophers objectify, de-humanize, and often conceptually exploit them. Carlson acknowledges, as do other feminist philosophers such as Elizabeth Kamarck Minnich, that there are differences of cognitive abilities among people, as well as there being great neurodiversity in many senses. However, also like Minnich, Carlson challenges what we make of this diversity. She does not engage in two-dimensional rejection or glorification of people with intellectual disabilities. As Tobin Siebers does in Disability Theory, Carlson takes seriously the positive and negative valences of disabilities—while challenging the very notion of assigning "positive" or "negative" judgments to human ability.

Carlson uses a tremendous breadth of philosophers and other theorists from a variety of disciplines and interdisciplinary fields, from "analytic" and "Continental" philosophers, feminist philosophy (of various modalities), bioethics, to feminist critical race studies, postcolonial theory and disability studies. She is equally deft with Ian Hacking, Jacques Derrida, Audre Lorde, and Michel Foucault. She deals with each theorist sympathetically and carefully, laying out their relevant ideas with great care even as she offers sometimes-devastating critiques. For example, she builds upon Derrida's underappreciated and deep critique of Foucault's work in History of Madness as falling far short, since Foucault (by his own lights) sought to provide a voice for madness itself. This failed in two ways: mad people do not speak for themselves in the work, and in a "deeper paradox," "Derrida calls into question the viability of a project that attempts to radically critique Reason by using its own instruments" (206). Invoking Audre Lorde's notion that the master's tools cannot dismantle the master's house, Carlson notes how both aspects of Derrida's critique relate to her own book. People with intellectual disabilities do not speak for themselves there. Instead, Carlson works to clear a space in which people with intellectual disabilities might be heard. She is using the master's tools, while reflecting upon their limitations. She employs philosophical methods, advocating for their potential usefulness, while challenging the ways that those tools have been used to perpetuate oppression.

The Faces of Intellectual Disability has two main sections detailing, respectively, the "institutional world" and the "philosophical world" of intellectual disability. Carlson introduces what she calls the "twin brothers"—"the idiot" and "the institution," explaining how notions of the mentally disabled and the institutions designed to house them do not bear an innocuous relation to each other. In the concluding chapter, she shows how these two worlds of institution and philosophy co-constitute "The Face of the Mirror."

Carlson is strongly influenced by Michel Foucault's History of Madness, which she describes as exposing "'Reason's monologue' in the face of a silenced other" (2). Carlson draws upon Foucault to analyze complex historical processes, drawing upon his critical treatments of the emergence of asylums, prisons, and clinics. The book discusses Foucault's work in a way that is quite accessible, explaining the methods as it goes along, so one need not be familiar with Foucault's work to follow what Carlson does with it. Yet experts on Foucault too will be impressed by her careful analysis, as she resists any oversimplification. She does not take any shortcuts. So too does Carlson marshal the resources of Iris Marion Young's "five faces of oppression." She powerfully puts Young's analysis of exploitation to work in teasing out just what is so problematic in the habit of scholars—especially philosophers—to invoke people with intellectual disabilities (along with others labeled "severely handicapped") in arguments for non-human animal welfare and rights. Carlson's discussion of "speciesism" (the notion that it is indefensible discriminatory prejudice to value human above non-human beings) is subtle and profound. She demonstrates what is lost when philosophers (such as Peter Singer) argue that our tendency to value even "severely handicapped infants" over non-human animals is arbitrary preference. Yet her argument does not devalue non-human animals. Instead of pushing back against Singer and others to trade allegiance from one group (non-human animals) to the other ("severely handicapped infants") she argues that it is vital to our humanity to value both groups.

Like Siebers, Carlson goes beyond the binary "medical versus social model" of disability, as well as "postmodern" models, showing how attention to intellectual disabilities advances these models and challenges them. So too, her critical encounter with "social constructionism." She writes, "Ultimately, I think the case of mental retardation shows that when the false dichotomy between 'natural kind' and 'socially constructed kind' is rejected, a new array of philosophical questions emerges" (91). In other words, intellectual disabilities are neither things in themselves nor mental projections. Rather, they are complex mutually constituting interactions of material conditions, ideas, impairments, discourse, and all kinds of other factors.

Carlson's work is careful, innovative, and visionary. It leaves me wondering: who are people with intellectual disabilities, what are their lives like, what are their stories? How do they represent themselves now, and how might they do so in the future if society becomes more willing and able to hear them? The Faces of Intellectual Disability shows how far many of us are from such a point. Carlson uses philosophical and historical tools to excavate and reveal how much is still in the way of treating people with intellectual disabilities as subjects rather than objects, to treat all of us as human.