WHAT DIFFERENCE DOES THE BODY MAKE? 49sory and motor systems. The sensory system brings stimuli such as light,
pressure, smell, and sound taken in from the eyes, skin, nose, and ears to
the brain. The motor system links the brain and spinal cord to muscles
throughout the body that move one about in the world, exposing one to
proprioceptive stimuli, while glands register various internal and external
states of the body (temperature, blood pressure, and so on). All of this pre-
discursive sensorimotor information is instantiated in the brain through
neural representations, which are not representations in the symbolic sense
but patterns of synaptic connections that are activated by specific senso-
rimotor stimuli. The brain combines multiple neural representations to
generate metaphors, which provide the basis for concepts. Cognition, then,
does not involve working through a set of symbols, but rather through
neural maps of our bodily experience in the world.
This view leads to embodied realism, where the content of a percep-
tion is tied to the bodily mechanisms of its production. For instance, col-
ors are neither objective, existing outside of perception, nor purely sub-
jective; rather, they are a “creation of specific neurobiological capacities
intra-^ acting with particles with specific wavelengths” (334). This version
of embodied realism in some respects recalls Donna Haraway’s doctrine
of embodied objectivity, where the material capacities of perception con-
dition what is known.^4 Both theories require us to abandon, as Lakoff and
Johnson put it, “the correspondence theory of truth, the idea that truth lies
in the relationship between words and the metaphysically and objectively
real world external to any perceiver” (334). But unlike Haraway, Lakoff
and Johnson emphasize biological constraint on thought. While neural
maps are learned, a biological body, with universal properties selected by
evolution, makes them possible. Because they are based on human phys-
iology, the range of basic human concepts is limited: “our sensory- motor
systems thus limit the abstract reasoning that we can perform. Anything
we can think or understand is shaped by, made possible by, and limited
by our bodies, brains, and our embodied interactions in the world” (5).
Because they are neurally instantiated, conceptual systems cannot easily be
changed. This is one reason why “we are not free to just think anything”;
that is, “our conceptual systems are instantiated neurally in our brains in
relatively fixed ways” (5).
While Lakoff and Johnson are concerned to identify the biological