1. Description of the obstacle
Bachelard (1938) showed that common sense is the first epistemological
obstacle to the advancement of physics and chemistry. I would
like to show here that common sense is also the first obstacle
to the advancement of physiological psychology (and, most likely,
to the advancement of any science).
The expression common sense refers to a system of beliefs and
skills shared by most people and acquired through mundane experience
in absence of special education. Naturally, this concept is
too broad. Any meaningful statement should refer not to the
whole concept but to some component of it. After all, each component
of common sense might very well be an obstacle on its own. The
present discussion will be limited to three components of common
sense, which will therefore constitute the first three epistemological
obstacles to physiological psychology: inflexible realism (i.e.,
the tendency to favor primary experience), spiritualism (i.e.,
the acceptance of transcendental causal agents), and naive humanism
(i.e., the placement of humans in a class apart from all other
In order to become a physiological psychologist (or any type
of experimental scientist, for that matter), one often needs
to abandon the world of everyday life and the sphere of primary
experience. Thus, primary experience tells me that the bathroom
floor is colder than the carpet in the bedroom. If I were to
keep this perceptual information, I would go nowhere as a sensory
psychologist. Indeed, if I use a thermometer to measure floor
temperature, I notice that the temperature is the same in both
rooms. Because the carpet is a better thermal insulator than
the ceramic tile, my feet lose heat to the floor more slowly
on the carpet than on the tile floor and, consequently, cold
receptors in the skin are not stimulated to the same extent.
This means that, independently of how natural and evident my
uneducated experience is, it may be incompatible with scientific
knowledge. It is evident, therefore, that suspicion about primary
experience is a salutary attitude. Inflexible realism is an
obstacle to the advancement of science.
Not much needs to be said about spiritualism. Although exceptions
can be found for any rule, most educated people today would agree
that ghosts do not exist, that astrology is a form of charlatanism,
and that science should not be mixed with religion. The scientist
as a private citizen is entitled to have his/her spiritual faith,
but empirical sciences have no room for spirits. Spiritualism
is an epistemological obstacle to science because it diverts
research from the search for empirical phenomena.
Humanism is a much more complex concept that has been constantly
changing since its origins in ancient Greece and the Renaissance.
I call naive humanism that modern form of humanism that seeks
an objective, although not scientific, knowledge of human nature.
The requirement of non scientificity comes from the humanist's
dissatisfaction with how modern science deals with issues of
subjectivity and human values. This is, therefore, a straightforward
epistemological obstacle: the naive humanist is openly against
science and would like to obstruct its progress. I call it naive
humanism because it requires shortsight not to realize that the
notion of objectivity sought by the humanist comes from science
(and not from some Land of the Absolutes) and, therefore, cannot
be found outside of science.
2. Examples of the obstacle
Examples of common sense as an obstacle to physiological psychology
can be found already at the two constituent sciences: psychology
and neurophysiology. Sigmund Freud is probably the most famous
psychologist of all times. Most of his work would be obstructed,
however, if inflexible realism were to prevail. For example,
in the sphere of primary experience there is a strong distinction
between sanity and mental illness. A person is believed to be
either normal or afflicted by some mental disorder. This distinction
is at the basis of the rule that requires initial determination
of the ability of a criminal to withstand trial. Freud always
insisted, however, that sanity and pathology are merely different
points in the same psychodynamic continuum (Freud 1958). Analogously,
behavior therapists believe that there is no difference at all
in the mechanisms by which normal behavior and deviant behavior
are established (Ullman & Krasner 1965).
Still in the domain of psychology, the primary notions of natural
morality and human dignity obstruct the acceptance of Freud's
thesis that psychological normality consists of a particular
way of dealing with (rather than excluding) the seeds of sexual
perversion with which all humans are born (Freud 1949). Also,
primary experience tells us that people behave this way or that
way because of their thoughts, expectations, wishes, and feelings.
This is incompatible with B. F. Skinner's contention that human
behavior is determined instead by the contingencies of reinforcement
and that wishes and feelings are collateral effects of those
contingencies (Skinner 1976).
In the domain of neurophysiology, a good example is that of
sensory modalities. Primary experience tells us that humans
have five senses: vision, hearing, olfaction, taste, and touch.
Neurophysiology tells us that, besides these five modalities,
we also perceive pain, warmth, cold, pressure, rotary acceleration,
and other variables (Ganong 1975). Clearly, we must be willing
to go past the simplicity of primary experience in order to accept
what neurophysiology takes for granted. Inflexible realism is
an obstacle to the advancement of science.
A formal defense of inflexible realism was carried out by the
phenomenological school of thought in the early 20th century.
This is evident in Merleau-Ponty's speculative theory of behavior,
according to which the study of behavior can be meaningful only
if it gives priority to primary experience over everything else
(Merleau-Ponty 1967). This is a straightforward case of obstruction
of science where the defendant voluntarily pleads guilty.
Regarding spiritualism as an obstacle, the issue of mental illness
will again provide a good example. Although the notion of mental
illness itself has been the object of criticism (Foucault 1972,
Szaz 1960), contemporary psychopathology certainly does not recognize
spirits as causal factor of disease. However, in the Middle
Ages madness was believed to be a consequence of demoniac possession,
and a popular therapy consisted of beating the patient in order
to induce the devil to leave the body (Coleman 1964). Naturally,
this belief in demons is an obstacle to modern psychopathology.
Religions are especially strong forms of spiritualism. They
certainly have more converts and more money than science. Therefore,
they have a strong potential to obstruct science. Fortunately,
because of the centuries-old separation between Church and State,
religions have not been major sources of obstruction. It cannot
be denied, however, that religion can be and has occasionally
been an obstacle to the development of science (Comte 1914, Nietzsche
1920, Weber 1963). For example, the Judaico-Christian religion
is supposed to have God's wisdom written down in the Holy Bible.
If this is the case, God disagrees with science on many issues.
Thus, in opposition to Darwin's theory of evolution, God says
that all species emerged at the same time, with the exact appearance
that they have today (Genesis 1, 20-25; 2, 19-20). Also, God
believes it possible to load two specimens of each animal species
in a rudimentary boat built by a family of inexperienced sailors
(Genesis 6, 19-20; 7, 2-3), whereas science tell us that this
would be impossible, as there are more than 750,000 species of
terrestrial animals on earth (which would demand much more housing
space, food stores, and sewage disposal than even modern technology
would be able to produce).
Finally, examples should be given of naive humanism as an obstacle
to the advancement of science. In its simplest form, humanism
is an obstacle because it demands a radical separation between
humans and all other animals. This contradicts at least three
facts of life science: 1) taxonomically, the species Homo sapiens
fits naturally into the family Hominidae, order Primates, class
Mammalia, and so on (Lincoln & Boxshall 1987); 2) intelligence,
a faculty once believed to distinguish humans from other animals,
is present in almost all animals and shows a phylogenetic progression
(Bitterman 1967); and 3) symbolic language, another faculty originally
believed to be exclusively human, can be found in other primates
as well (Gardner & Gardner 1969, Premack 1971, Rumbaugh 1980).
There are, of course, more subtle forms of humanism. For instance,
Carl Rogers and other members of the so-called "third force"
in psychology refuse to accept mental illness as an impurity
that maculates human nature. In other words, human nature is
too pure to be stained with disease, and psychotherapy should
aim at helping the patient grow psychologically rather than healing
his/her illness (Rogers 1977). Naturally, this attitude is an
obstacle to any scientific theory of psychopathology. Supporters
of anti-scientific organizations should have the right to free
speech as everyone else, but scientists have the right (and the
moral duty) to reject foreign threats. Other members of the
third force openly oppose the concept of motivational homeostasis
(which is a cornerstone in physiological psychology) because
human existence is allegedly characterized by auto-transcendence
rather than by the satisfaction of motivational needs (Frankl
1969, Maslow 1969). This is another obstacle to scientific psychology.
Incidentally, it is curious that Maslow's theory of meta-motivations
predicts that non-motivated perception should be more accurate
than motivated perception (Maslow 1968), whereas empirical research
shows that perceptual acuity is higher at an intermediary point
within the indifference-anxiety continuum (Vernon 1970).
Physiological psychology was explicitly criticized by Frick
(1971) for failing to study human behavior in a humanistic way.
Naturally, this indicates a type of "ethical" humanism, but
obstacles to physiological psychology may come also from a "philosophical"
humanism. For instance, Sartre (1948) criticized scientific
psychology for fragmenting knowledge and failing to produce a
philosophically meaningful understanding of the human being.
Naturally, the psychologist's response should be: "What you
see are the results of my scientific research. If they do not
satisfy your philosophical convictions, it is probably because
your convictions are wrong."