Mad Cows and So On: Science Teaches Us to Be Careful
Ana M. Soto and Carlos Sonnenschein
International Herald Tribune, 1 December 2000
Since Greek antiquity, humans have been grappling with the question
"How do we know what we know?" This is the subject of epistemology, a branch
of philosophy. This subject is relevant to today's reality. It has to do
with problems that our societies and governments are faced with - mad cow
disease, global warming, genetically modified organisms, endocrine
disruptors, the use of growth hormones in beef.
Four centuries after the Scientific Revolution and two centuries
after the Industrial Revolution, countries in the Northern Hemisphere enjoy
a high standard of living. This material and technological progress is
considered to be the result of our solid and almost complete scientific
understanding of utilitarian and academic topics.
Lay people tend to assume that science is a solid construction with
clear-cut answers for everything. Hence, policy should effortlessly be
derived from "the facts." The public has been led to believe that
science-based policy should produce self evident solutions acceptable to
everyone. But recent events show that this is a pipe dream.
Uncertainty is built into knowledge. Here is how.
Scientists propose a hypo thesis about how or why a certain natural
phenomenon occurs or how nature may react to the introduction of a man-made
artifact. Next, they test the hypothesis. Finally, their findings are
Several unresolved issues are related to this process. The first is
whether or not hypotheses can be proved and be shown to be an airtight
interpretation of how nature works.
The prevalent view, put forward by Karl Popper, is that hypotheses
can only be falsified. That is, a given interpretation of facts stands until
it is proved wrong. Thus, scientists are uncertain about when a hypothesis
may be taken to be "true." It is only through a long process of accumulation
of evidence that the hypothesis acquires robustness.
For example, it took more than 100 years for the scientific
establishment to accept the proposal of Copernicus that the sun is at the
center of the planetary system we inhabit.
Granted, in the long run science works well in approximating
understanding of how and why nature works.
The second vexing issue has been whether facts can stand on their
own. A scientist gathers results because he or she has a hypothesis to
explore. Scientists, like lay people, have their own individual perceptions
of the world.
The questions that a scientist asks are not neutral, but colored by
the premises that he or she chooses from those that look plausible.
Collecting theory free data, as proposed by the supporters of inductivism,
has been a difficult, largely fruitless, task. Charles Darwin remarked that
"one may as well go to a gravel pit and count the pebbles and describe the
colors." Thus, data are always theory-laden.
The third issue regarding uncertainty is that biology, more than
physics, is a historical science. Evolution is the history of life, and of
how "old" molecules and cellular structures were put to new uses at a time
when no intelligent creature was there to witness and record it. Experiments
are done for the most part to understand how organisms living today are put
together and how they work.
Given the many interacting variables that framed the world that is
our current home, scientists arbitrarily eliminate those that, in their
judgment, don't seem critical to running their experiments in laboratory
conditions. The results lead to conclusions that are not always applicable
to the whole of biology, since we are mostly ignorant about the history of
In this regard, we do not know what we do not know.
One should remember that, in fact, we are guessing - yes, guessing -
how the world we are a part of was put together and how it is reacting to
our innovations. This is why it has been so difficult to anticipate the
consequences of our creativity.
For example, DDT, which was designed to control pests, ended up
altering the reproductive organs of wildlife and humans. Wildlife and humans
can become the unintended targets of well-meant but poorly planned attempts
to improve our standard of living through short-term fixes.
In summary, we hardly understand the impact of technology in its
long-term effects. Slowly but surely that is now becoming obvious.
As long as the precise history of how organisms evolved is unknown
to us, we risk unexpected consequences when applying knowledge gathered in a
highly focused laboratory setup that is hardly comparable to the "real
Why should it be acceptable that cattle be treated with hormones?
Why are ruminants that are adapted to eat grass fed with offal-derived
How certain should we be about the safety of these practices when
experience has shown us that unthinkable effects - the ozone hole, global
warming, mad cows, hormones in the environment - can result from seemingly
benign procedures or products? What is the benefit of these innovations,
besides the obvious narrow purpose of increasing the profit of the
Awareness about the uncertainty of science and technology must have
a place in policy decision-making. The value of the precautionary principle
is readily apparent.
The writers, professors at Tufts University School of Medicine and
authors of "The Society of Cells," contributed this comment to the
International Herald Tribune.
The full text of this article is available for a limited time on the
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