Do Human Beings Have a
Nature?
Richard Samuels
Ohio State University
Introduction
• 
Hume: …a topic of
“unspeakable
importance” (Treatise,
Sec. 1)
• 
The subject of human
nature is largely
concerned with our
mental capacities.
• 
Hume’s science of
human nature is
presented as empirical
psychology.
The project of trying to discern human nature also
remains prominent within contemporary cognitive
science.
•  Chomsky:
–  Not even the most extreme postmodernist can seriously argue that there is no
such thing as human nature. They may argue that the exact properties of human
nature are difficult to substantiate -- this is certainly correct. However, it is
impossible to coherently argue that an intrinsic, universal human nature does not
exist. This amounts to the belief that the next human zygote conceived might just
as well develop into a worm or a crab as a human being. (Chomsky, 1970)
–  Similar attitudes abound:
•  EP types, but also intellectual descendants of Hume
•  What could Hume, Chomksy and the like sensibly be construed
as seeking to understand, when they purport to enquire into
human nature?
Object of enquiry cannot be human nature in a
traditional essentialist sense.
•  Traditional essentialist view of human nature:
–  A set of intrinsic properties instantiated by all and only humans
possess that define membership of the kind, and cause other
properties associated with being human.
•  For familiar reasons it is highly implausible that humans qua
biological species possess such an essence.
–  Incompatible with the taxonomic practices of evolutionary
biology (Hull)
•  Note: Little evidence that Chomsky and the like seek to identify
properties that define species membership.
•  If cognitive scientists who purport to study human nature are
engaged in a sensible project, the relevant notion of human
nature cannot be the traditional essentialist one.
•  It must be an alternative —or replacement— conception of
HN. Questions
•  What do cognitive scientists seek to understand
when they purport to study human nature?
•  Is it sufficiently similar to the traditional conception
of human nature to merit the honorific “human
nature”?
–  Specifically: Does it satisfy the various theoretical roles
that human nature has traditionally been intended to play?
Game-Plan
1.  Some central scientific roles of human nature.
2.  A nomological conception of human nature
3.  A causal essence view of human nature
I. The Scientific Roles of Human
Nature • 
Human nature –and theories thereof– have traditionally
called upon to play a range of theoretical roles in science.
1. An organizing role
• 
Delimit an area of scientific enquiry:
• 
It seems to me that one might speculate a bit further …and ask whether the
concept of human nature …might not provide for biology the next peak to try to
scale, after having…already answered to the satisfaction of some the question of
what is life. (Chomsky, 1970)
2. Descriptive functions
•  Describe universal features of human beings
–  There are many things that are true of only some humans. –  An account of human nature is widely assumed to be concerned only with
those that are universally –or at least very frequently– true of human
beings.
•  Describe species uniqueness
–  Properties of our species that are not properties of others.
•  …our most revealing efforts at self-definition tend to dwell on our
exceptionality, rather than on our common biological heritage. Our uniqueness
lies especially in distinctive features of the human mind that make us a radical
new force in the known universe. (M. Donald “The Definition of Human
Nature”)
•  3. Causal explanatory functions
•  Causally explain the distinctive properties of human beings
•  Causally explain the species-typical properties of human beings.
–  Aspects of human nature are invoked in order to explain robust
generalizations about human beings.
•  4.Taxonomic function
–  Define kind membership
•  I.e. Specify what it is to be a human being II. Human Nature as a Nomological Nature
•  Sometimes human nature is characterized as involving a
commitment to the existence of species-typical properties or
regularities. –  Machery & Barrett: A commitment to the existence of human nature
is a commitment merely to the fact that “there are generalizable
statements that we can make about humans.” •  “…there are some properties that, characteristically and for the most part, humans
posses.”
–  Machery: “Human nature is the set of properties that humans tend to
possess as a result of the evolution of their species.”
Notice: This is far weaker than traditional HN
essentialism
•  Regularities need only be species-typical as opposed to strictly
universal. –  An acknowledgement of the fact that there are few, if any, scientifically
interesting regularities that apply to all humans.
–  Consistent with the existence of kind members who fail to be subsumed
by regularities.
•  Regularities need to hold only of humans.
•  Consistent with the idea that regularities can change over time.
–  It’s coherent to suppose that human beings evolve in such a way that many –even
all– extant regularities cease to be regularities that apply to humans. Q: Do humans have a nomological nature?
• 
Presumably yes.
There are many disciplines that generate substantial numbers of
species-typical generalizations about human beings.
»  Human Anatomy and hysiology
»  Neuroscience
»  Psychology
– 
• 
– 
Exactly analogous to the situation for other organisms.
Such regularities will count as aspects of our nomological nature.
In the domain of psychology there appear to be
many robust regularities
•  Potential Candidates
•  More-or-less randomly selected.
–  Humans speak languages
–  Humans engage in pair-bonding
–  Humans make moral judgments
–  Humans engage in means-ends reasoning
–  Categorization:
•  Typicality Effects ≈ The extent to which a member of some member of a
category C is a typical instance of C, correlates with independent
psychological measures.
–  E.g. Speed of response, accuracy of categorization judgments, order of
recall.
–  Memory
•  Power laws of learning and forgetting (Anderson)
–  Much data remembering and forgetting can be fit by power functions
•  Reaction times in recall tasks is influenced by statistical and/semantic
associations.
–  Concept acquisition
•  The concept ONE is acquired before the concept FOUR (if indeed the
latter is ever acquired).
•  Humans possess the concept BELIEF prior to the age of 5.
–  Visual Perception
•  Plethora of illusions that are robust across cultures.
•  Upshot:
–  It’s prima facie plausible that sciences interested in
psychological phenomena can identify speciestypical regularities.
Q: Which of the traditional roles assigned to
Human Nature can nomological natures play?
• 
Delimit/define areas of enquiry ✔
–  Human biology, psychology etc. would be the study of this essence and the
properties associated with it.
• 
Describe universal species-typical features of human beings ✔
• 
Describe species unique features ✔
–  Assuming that some species-typical properties of humans are not shared by other
organisms.
–  Though on the present conception of human nature, there is no presumption that
only features that are unique to humans form part of our nature.
•  Define kind membership ✖
–  Seems not.
•  Causally explain the distinctive aspects of human beings ✖
–  Nomological nature don’t explain why many generalizations can be made about human
beings.
–  It just is those generalizations.
•  Causally explain the species-typical properties of human beings ✖
–  As Above
Summary
• 
Nomological Natures play some of the roles that human
nature is traditionally supposed to play. But there are other
roles it won’t play:
– 
– 
• 
Won’t do the causal explanatory work that the notion of human
nature has traditionally been called upon to perform. Won’t play the relevant taxonomic role.
Q: Can we make sense of a causal conception of human
nature ? – 
i.e. as something that plays a central role in the causal explanation of
species-typical –including unique, species-typical– aspects of human
psychology. III. Human Nature as Causal Essence
•  Rough idea: Human nature is a causal essence of some sort.
–  Casual essences need not provide necessary and sufficient conditions
for kind membership.
–  Rather they are underlying mechanisms that explain many of the
properties and regularities associated kind membership
•  Casual Essentialism about Human Nature (1st Pass):
–  Human Nature is a set of empirically discoverable causal mechanisms
(processes, structures and constraints etc.) that explains the covariation of the various properties and regularities associated with
human beings.
•  Especially: cognitive/psychological properties and regularities.
Developing the view 1: Homeostatic
Property Clusters
•  There may be many ways of elaborating the present proposal.
–  See D. Walsh on evolutionary esentialism
•  One possibility: Invoke a Boydian view of natural kinds
–  Perhaps the currently most popular account of natural kinds (Boyd)
•  K is natural if: –  H1. It is associated with a contingently co-varying property cluster –  H2. There is some set of empirically discoverable causal mechanisms,
processes, structures and constraints –a causal essence, if you will— that
explains the co-variation of these various symptoms.
–  H3. To the extent that there is any real definition of what it is for something to
be a member of the kind, it is not the symptoms, as such, but the causal
essence that defines membership. •  Example: Flu
Developing the view 2: What’s the property
cluster?
•  The HPC view presupposes the existence of properties that reliably
covary with each other.
•  Q: Are there such covariations?
•  A.Yes.
–  This is precisely what a nomological conception of human nature
captures:
•  A set of species-typical regularities.
–  Regularities in linguistics, perceptual psychology, social psychology etc. are
things that might be explained by Boydian causal essences. Developing the view 3: Time-Scales
•  The Boydian view of natural kinds is consistent with explaining
property co-variation in terms of mechanisms operating at different
time-scales.
•  Rough division:
–  Evolutionary processes and mechanisms –  a set of phylogenetic processes and mechanisms that cause human species-typical properties.
–  Developmental mechanisms
•  Developmental biological processes and mechanisms
•  Psychological/Learning mechanisms that produce new psychological states and structures.
–  Synchronic mechanisms
•  Psychological mechanisms
–  Visual processing, memory, reasoning mechanisms etc.
•  Neural mechanisms
Q: Which time-scale is relevant to our
understanding of human nature?
•  Presumably: If we aim to explain species-typical regularities, as
such, then all time-scales will be relevant.
–  But as a matter of fact cognitive scientists are typically less
concerned with evolutionary processes than with more
proximal cognitive and neural mechanisms.
•  Those involved in online processing and in the development
of psychological states and structures.
•  Indeed characterizing such mechanisms is arguably the
central goal of cognitive science.
Take-Home: Causal essentialism about human nature
satisfies many of the traditional roles assigned to
human nature.
•  Define kind membership ✖
–  But for familiar reasons this is a requirement that will need to be given
up.
•  Delimit/define areas of enquiry ✔
–  Human biology, psychology etc. would be the study of causal
mechanisms and the properties associated with them.
•  Describe species-typical features of human beings ✔
–  By assumption, the mechanisms are species-typical
–  A description of species-typical regularities would be an account of the
property cluster.
•  Describe species unique features ✔
–  Assuming that some species-typical properties of humans are not shared by
other organisms.
•  Causally explain the species-typical properties of human beings ✔
–  Causal essences are invoked in order to explain robust generalizations about
human beings.