Diderot’s Letter on the Blind as Disability Political Theory

Date01 February 2020
Published date01 February 2020
Subject MatterArticles
/tmp/tmp-170cXgrqJPHcRe/input 843063PTXXXX10.1177/0090591719843063Political TheoryHirschmann
Political Theory
2020, Vol. 48(1) 84 –108
Diderot’s Letter on
© The Author(s) 2019
Article reuse guidelines:
the Blind as Disability
DOI: 10.1177/0090591719843063
Political Theory
Nancy J. Hirschmann1
This essay considers Denis Diderot’s Letter on the Blind for the Use of Those
Who Can See
as a work that can contribute to a disability political theory. By
recounting the experiences of visually impaired persons in their own words,
Diderot opens up possibilities for a disability politics of self-representation,
maintaining that sighted persons should listen to blind persons’ accounts
of their own experience rather than relying on their own imaginings and
assumptions. By using blind experiences to challenge a philosophical problem
that intrigued philosophers of the seventeenth and eighteenth centuries amid
often-unsuccessful efforts to “cure” blindness through cataract surgeries,
Diderot develops a powerful critique of the empiricist stress on vision as the
primary source of perception and provides a remarkably forward-looking
critique of disablist attitudes toward the blind. Through this philosophical
discourse, he engages a political argument about the way knowledge is
gathered, evaluated, and interpreted through relationships of power.
Diderot, blindness, disability, empiricism, knowledge
1Department of Political Science, The University of Pennsylvania, Philadelphia, PA, USA
Corresponding Author:
Nancy J. Hirschmann, Department of Political Science, The Ronald O. Perelman Center
for Political Science and Economics, The University of Pennsylvania, 133 South 36th St.,
Philadelphia PA 19104, USA.
Email: njh@sas.upenn.edu

Denis Diderot’s Letter on the Blind for the Use of Those Who Can See is an
understudied but important text for political theorists concerned with the
power/knowledge nexus. Despite French scholar James Fowler’s declaration
that Diderot was “one of the three greatest philosophes of the French
Enlightenment,”1 and Tracy Strong’s locating him in “the society of the
lumières,”2 the editor of the Encyclopédie and author of numerous essays is
not discussed, cited, and analyzed by political theorists as commonly as other
French contemporaries like Rousseau. Moreover, Diderot’s Letter does not
readily seem a political text, compared to some of his Encyclopédie entries,
or even Rameau’s Nephew or Supplément au Voyage de Bougainville.3 Yet in
arguably his most “original, controversial, and dangerous book,”4 Diderot
deploys blindness to illustrate the power entailed in how we approach knowl-
edge and the kinds of evidence that we consider valid. It thereby affords a
rare opportunity to add a disability perspective to the history of political
In “the great confinement” of the seventeenth and eighteenth centuries,
physically disabled persons were institutionalized with the insane and cogni-
tively disabled and were perceived as cognitively “deficient” until the second
half of the twentieth century.5 But even today, blindness is a common meta-
phor for the failure of knowledge: we are said to be “blind” to things that we
are ignoring; darkness is linked to ignorance, as in Plato’s allegory of the
cave; “seeing” is frequently used as a synonym for “understanding.” As Joan
Scott puts it, in the modern world “seeing is the origin of knowing.”6 Martin
Jay notes modernity’s “ocularcentrist bias”7 wherein sound and touch are
assumed to yield only a limited experience of external objects.8 Scholars such
as Catherine Kudlick and Zina Weygand have offered powerful accounts of
the everyday and spectacular accomplishments of visually impaired persons
throughout history, but these do not enter into the political theory worldview.9
And although studies show that rates of happiness are as high among people
living with disabilities as those who do not, many able-bodied persons disbe-
lieve such empirical evidence, even to the point of preferring death to having
a “severe disability such as blindness.”10
The persistence of such attitudes stands out against Margo, Harman, and
Smith’s claim that Diderot’s Letter “may represent the turning point in
Western attitudes toward visual impairment.” They hold that developments
for the blind, including the establishment of the first school for the blind by
Valentin Haüy in 1784, followed forty years later by the invention of Braille,
were attributable in part to Diderot’s 1749 essay.11 Diderot challenges nega-
tive beliefs about blindness by providing accounts of blind persons engaging
in a wide variety of activities ranging from mathematics and philosophy to
teaching children to read, threading needles, guiding sighted persons through

Political Theory 48(1)
town, cleaning house, playing musical instruments, blacksmithing, telling
time by the sun, and other quotidian activities that sighted people cannot
imagine doing without vision. Diderot also provides an account of what blind
persons say about their experiences and their knowledge. Such attention to
blind experiences, Diderot suggests, can enhance the knowledge of sighted
persons, revealing things that they cannot “see” precisely because of their
dependence on sight. As D’Alembert’s Encyclopédie entry “Aveugle”
(“Blind”), based on Diderot’s Letter, claims, “the sense of sight being very
fitting to distract us by the quantity of objects which it presents to us at the
same time, those who are deprived of this sense must naturally and in general
have more attention to objects falling under their other senses.”12
Seeking to establish the value of touch, and to unseat “the so-called pri-
macy of vision as a vulnerable link in Cartesian reasoning,” Diderot “contests
prevailing views of what the senses contribute to knowledge and understand-
ing.”13 As today’s disability scholars might put it, ableism, like sexism and
racism, interferes with the ability of dominant groups to hear, understand, or
believe the knowledge claims of the subordinated; what Miranda Fricker
calls “epistemic injustice.”14 Blind persons do not know less, Diderot indi-
cates; they know differently, in two ways. They can achieve similar knowl-
edge as sighted persons, but through different means, particularly touch, and
through touch they can also gain different knowledge.
Additionally, by recounting the experiences of visually impaired persons
in their own words, Diderot makes possible a disability politics of self-repre-
sentation. As Barbara Arneil has argued, “negative self-images” of disabled
persons are pronounced in the history of political theory, and “the insidious
power of negative language” relating to disability should be countered by
more accurate accounts that recognize positive capabilities.15 Diderot pro-
vides such accounts in detail, focusing on several accomplished blind per-
sons, thereby anticipating contemporary disability scholars who seek to
persuade able-bodied readers that disabilities of many kinds do not entail a
less valuable life; that many disabilities, like blindness, do not make people
helpless and dependent; and that disability is not necessarily, and not only, a
matter of suffering.
A significant part of Diderot’s project entails “Molyneux’s problem,”
which asked: if “a Man born blind, and now an adult” learned the shape of a
cube and a sphere by touch and suddenly had his eyesight “restored,” could
he tell, simply by sight, which was the cube and which was the sphere?16 This
puzzle served as a popular weapon of Enlightenment empiricists against
rationalism. Like many of his fellow philosophes, Diderot rejected rational-
ism and its notion of innate ideas, disparaging it as “more concerned with
drawing together and connecting the facts it possesses than in accumulating

new ones.”17 Like his fellow empiricists, Diderot believed that experience
was the basis for knowledge;18 a dedicated materialist, he even believed the
soul was material, made up of molecules that we lacked sufficient scientific
methods to observe.19 Materialism “had to be founded on an objective experi-
mental science,” and Anthony Strugnell maintains that in the Letter material-
ism becomes for Diderot “more than speculative philosophy,” which it had
previously been in his work.20 But in the Letter he opens up questions about
how “experience” is evaluated and becomes translated into knowledge
claims, particularly challenging the centrality of visual evidence to empiri-
cism and emphasizing the value of different sensory perceptions, especially
After establishing the context for the Letter, my argument shows that
Diderot makes a notable effort to communicate the experience of blindness
from the perspective of blind persons. Using these perspectives to consider
Molyneux’s problem, Diderot seeks to correct other empiricists’ arguments
and include blind persons’ knowledge. I suggest that it serves as a potential
model for a disability political theory. Some caveats are in order, however.
Contra Margo, Harman, and Smith, Diderot was not an unambiguous
champion of disability; his Refutation of Helvetius suggests that physically
disabled children should not be educated along with “normal,” ones reflect-
ing his materialist determinism wherein different bodily capacities deter-
mined different intellectual...

To continue reading

Request your trial

VLEX uses login cookies to provide you with a better browsing experience. If you click on 'Accept' or continue browsing this site we consider that you accept our cookie policy. ACCEPT