Why the Topic of Bioethics in Science
A New Look at an Old Debate
by Carolyn Csongradi
Is More Influential Than "Nature"
Experiences are written onto the mind, which is essentially a
blank slate. We have knowledge of the world because we learn from
experiences. "Prior to experience, the human mind is a 'white
paper', void of all characters, without any ideas. " Each
aspect of behavior is acquired from the environment.(23)
The philosopher Hume thought the mind a blank slate(tabula rasa)
on which experience could be written. Hume was preceded by another
philosopher, John Locke who
was also a contemporary of Isaac Newton. They belonged to a school
of thought known as Empiricism which
states that knowledge is derived from experiment and observation
and were joined by science contemporaries, Sir Francis Bacon and
Robert Boyle.(16) Locke thought all knowledge of the world was gathered
through sensory experience. This information coul
d be manipulated
into more complex ideas by reflection and reasoning. He saw the
mind as having innate powers of observation, but not of ideas
which were to be constructed from sensory input. Hume, expressing
the extreme of skepticism, felt nothing was objective, everything
was chaotic, connections between impressions were imagined.
Critics observed that this line of thinking could not explain
cause and effect in a novel situation unless one was allowed to
rely on a multitude of previous experiences. Berkeley, a contemporary
of Locke, argued that Locke's logic led to the conclusion that
all knowledge ultimately becomes ideas in the mind which may or
may not resemble reality. Our perception of nature is a mental
experience. Kant, who was familiar with the discoveries of Newton,
helped solve this conflict. He argued that while knowledge came
from sensory information, we have inherited the ability to categorize
sensory information with respect to time, space and causality.
A rock thrown at a window will break the glass. The future should
look like the past.
The "Natural Law Theory" argued that moral principles
could be discovered through careful reflection.(31) Reasoning was
needed to counter or balance the natural inclinations of individuals.
These laws of nature, rather than the individual customs and preferences,
determined what action was "right". While the powers
of reason were a part of the mind, principles were not. They remained
to be found by observing nature.
Essentially, this is a philosophical discussion about how sensory
knowledge is organized by the mind. Do we have an innate ability
to manipulate objective sensory information or must this be learned
entirely from experience? This difference in opinion is not likely
to lead to any resolution of questions concerning the origin of
values or moral knowledge nor explain the large body of scientific
uating structural changes in biologic systems with
In a recent best seller, neurologist Oliver Sacks examined a man,
Virgil, who had had cataracts clouding both eyes following an
early childhood illness.(37) Earlier, several physicians had examined
Virgil's eyes and concluded his retinas had been damaged as well
by the same illness and concluded cataract removal would be futile.
As an adult Virgil was functionally blind. At age fifty, Virgil was once again examined by a specialist whose opinion differed from earlier recomnnendations. This physician felt Virgil's retinas might have limited function
and recommended removing both cataracts. Virgil agreed and thus
became a fascinating opportunity for Sacks to study perception
and the role of nature in visual learning.
After the surgery, Virgil reported seeing blurred visual images
and had little ability to identify what he was seeing. For instance,
a face seen wasn't known as a face until touched and he was unable
to make sense of facial expressions. His primary route for knowledge
of objects continued to be tactile. Over time, he showed little
sense of depth perception, having difficulty judging objects in
the distance from those which were close. He was as Sacks said,
After struggling for many months to learn to navigate visually,
Virgil began to have long periods of spontaneous blurriness which
were not observed by his doctor in patients who had had cataracts
for a much shorter time. Sacks and the opthamologist concluded
Virgil's visual cortex was in neural overload and responded by
a sudden shutting down. This process of disconnection has been
observed in many different animals when feeling overwhelmed.
In the end, his retinas continued to have the same physical appearance
and Virgil's perception continued to deteriorate. Virgil became
more blind than he had been befo
re his operations, although he
experienced rare moments when he could see something accurately.
Whether this ultimate loss of vision was related to an intervening
bout of a near lethal pneumonia or excess sensory stimulation
could not be determined. What is clear is that nurture plays a
major role in our ability to make sense of visual stimuli. Seeing
is not necessarily "to see". Even if an alternative
mode is developed for object identification, this coneptual information
does not appear to transfer readily between sensory systems.
Nature and Nurture Continued: