Journal of Philosophy, Science & Law
7, December 5, 2007
Precautionary Tale: Towards a Sustainable Philosophy of Science
Dr. Andrew Michael Baker*
* School of Natural Resource Sciences, Queensland University of Technology (Australia)
Abstract: Sustainable management of dwindling
resources is perhaps the biggest challenge facing the human species.
Successfully addressing this challenge requires holistic perspective: a
nebulous connection across disparate realms of science, economics and
sociopolitics. Here, I examine some important historical philosophical
ideas in our understanding of science. I relate these ideas to how science is
generally perceived today. And I question how our view of science is applied
through modern policy incorporating a variant of the ‘precautionary principle’,
a notion that essentially attempts to articulate a cautious approach to
management in our rapidly changing world. I conclude that deeper, philosophical
thought would be much welcome: both for clearer purpose within science itself
and in order to move forward more strategically in applied areas, such as
sustainable management of our planet.
the world today, it is becoming increasingly clear that finding a sustainable
solution to our resource crisis is the key to our long-term survival as a
species. Topics such as biodiversity loss, land degradation, environmental
restoration and, most notably of late, global warming, are fuelled by ongoing
debate. They have become scrutinised and thrust onto the world stage. Public
opinion of these issues is much welcome, even if criticised as being largely
whipped by media frenzy rather than rational deliberation. It plays crucial
part in democratic process on the path toward policy change and a more
sustainable future for us all. And yet finding solutions to sustainability
issues remains humanity’s greatest challenge: it requires a broad perspective,
spanning the realms of science, economics and policy. In rewriting policy,
Science must grapple head-on with the Law; an often unhappy union. Also, we
must strive towards a fusion between, on the one hand, the goal of an
objective, methodical interpretation of our world, and on the other hand, our
subjective value judgements of how changes to the environment may impact upon
our lives. In our search for these sustainable solutions, we continue the
struggle to be precautionary in our approach to environmental management.
the 1992 Earth Summit at
of 100 countries united to forge a blueprint for global sustainable development
in the 21st Century. A key document emerging from these meetings
became known as Principle 15 or ‘The Precautionary Principle’. Here is a bite
size chunk of it:
“In order to protect the
environment, the precautionary approach shall be widely applied ……where there
are threats of serious or irreversible damage, lack of full scientific
certainty shall not be used as a reason for postponing cost-effective measures
to prevent environmental degradation.” (UNCED 1993)
short, this principle means: if you are going to do something that might harm
the environment in irreversible ways, then be careful. It springs from the old
rule taught to first year medical students: ‘First, do no harm.’ Just suppose
you are going to build a high-rise complex: to get permission to proceed, you
first need to demonstrate that you’re not going to do any environmental damage.
Given the difficult wording and its importance for global management and
restoration projects, it shouldn’t surprise that in the years following the Rio
Earth Summit there was heated debate in all circles: economics, law and science
(see, for example, Gollier, Jullien, and
Treich 2000; Saladin 2000; Stewart 2002).
terms of principle 15 have been discussed by others (e.g., Kaiser 1997; Lemons,
Shrader, and Cranor 1997; Martin 1997): the wording gives a somewhat muddied
view of the role of science in the process of being sustainable. And the fact
that the Precautionary Principle is worded in slightly different ways in
various international laws has meant further confusion. Because of this, effort
has been made to try and clarify how science should be viewed in such
statements, particularly in regard to the nature of science (e.g., Arrow et al.
1996; Downes et al. 2002) and the gap this may create between developments in
science and policy (Bradshaw and Borchers 2000).
years after the Rio Declaration, 32 participants met at the Wingspread
Conference Centre in
. The global
community were represented at the conference by a diverse array of
stakeholders: international lawyers, economists, scientists, indigenous persons
and laypersons. The results of the meeting were a series of statements which
tried to clarify some of the previous confusion written in the original Rio
Declaration, six years before. In this attempt, the participants introduced a
notion of ‘cause and effect’ into the documentation. Here is a relevant
“Where an activity raises threats
of harm to the environment or human health, precautionary measures should be
taken even if some cause and effect relationships are not fully established
scientifically.” (Wingspread 1998)
notion of cause and effect was subsequently adopted by the European Union in
2000 and has since been used in other sustainable management documents around
the globe. Consider a recent example: in May of 2007, the World Conservation
Union (IUCN) proposed new guidelines for applying the precautionary principle
to global biodiversity conservation and resource management. In this document,
they stipulate that the precautionary principle should be most relevant where
there is scientific uncertainty. And where a threat is relatively certain, more
preventative measures should be taken. They define ‘relatively certain’ as
where a causal link between an action
and environmental damage can be established (IUCN 2007).
this paper, I would like to take a different approach to other published
critical works on this topic. I will discuss some important points about the
continued misuse of the ‘cause and effect’ concept in modern policy in relation
to the work of philosophers of science, David Hume and Karl Popper.
Precautionary Principle forms a cornerstone of sustainable management: yet
philosophy shows that we are missing something important in how we continue to
portray science to the world. My main purpose in discussing some of these
problems is to raise awareness of the importance in understanding more clearly
both the strengths and weaknesses in science. And I want to argue the need for
deeper, philosophical thought about the role of science in areas such as
philosophy of Karl Popper forms the foundation of the modern scientific method.
Popper lived in the 20th Century and his work is important not only
to modern science but also to our notions of social change (refer to Popper
1959, 1962; Magee 1985, 2001). Basically, Popper believed living was an ongoing
process of problem-solving. The great internal struggle that Popper had in developing
his philosophy of science was linked to the established ‘problems with
Hume, a Scottish philosopher who lived about two hundred years before Popper,
had become famous for proposing his classic problem with induction. In this, and other ways, the work of these two
great thinkers is related and has relevance to our application of science via
policy documents to secure a sustainable future, as we shall see.
the time of David Hume, induction (thanks largely to Francis Bacon ) held
sway and formed a cornerstone of science. Induction may be viewed as a process
of coming up with a general pattern or law based on lots of evidence from
specific examples. For instance, I may notice that swans living in various
are white. Then I may travel to
notice at a number of different locations, white swans. I notice that wherever
I go, if ever I see a swan, it is white. I may then put forward a general rule
to try and explain this situation: all swans are white. This is a very nice
example of induction, because it also demonstrates its flaw: there can always
be an exception to the rule. If I go to
, I will see black swans. So part of Hume’s
problem with induction was that, because there can always be an exception to
the rule, it is not logical to use it. Of course, the great attraction for
modern science is that we can generalise, form a theory, and make great
imaginative strides forward in thinking by using induction. But Hume’s age-old
argument was that this method of thinking has a fatal flaw: no matter how many
swans I look at, there can always be
another one that does not fit my proposed theory. Another aspect of Hume’s
problem was this: the notion that the future will resemble the past cannot be justified
(Hume 1739). Taken to its sceptical
conclusion, Hume’s problem is far-reaching indeed. He claimed that we cannot
use induction in our attempts to understand nature because to do so assumes
that this process will work in each successive case, which is itself inductive.
In other words, we are using an inductive process to justify induction, which
is circular. But neither can we justify uniformity in nature deductively, using
evidential support, because the future will not necessarily resemble the past
(Hume 1739). Since these are the only ways of justifying conclusions from
premises, induction is never justified.
idea is so fundamental and well articulated that it has never to this day been
shown wrong. Almost two centuries later, Karl Popper’s greatest contribution
was to sidestep (yet not solve) Hume’s problem with induction; in doing so, he
paved the road to our modern scientific method. Popper did this by making
induction less important in science: he wanted us to boldly use induction in
proposing theories but to then carefully test and try to disprove them. To
Popper, it is the testing of the
theories that is the critical part of the process: induction is just used to
help the creative juices flow in coming up with a theory to test.
the face of the problems of induction, Popper’s chief success was in not
falling into the obvious trap so neatly revealed by Hume. Popper is not trying
to provide further evidence or find another case that supports the theory.
Instead, he is trying to find some evidence that doesn’t agree with the theory (Popper 1959; Magee 1985). In this
way, if we find some evidence of a swan that is not white, we can reject the
theory that all swans are white and progress in a logical way. So, although
Popper advocates use of induction in theory formation, the major focus of his
method is the logical and critical testing of otherwise tentative theories.
what happens when we find our black swan? Well, we can modify the theory about
our swans and test it again using Popper’s method. This process of testing,
followed by modification and further testing, goes on and on…endlessly. And do
you know in
there are swans with black necks and white bodies! That is science; there is no
final answer. There can be no final
answer. Put simply, there can always be an exception to the rule, and the
scientist must keep searching for it, forever. We must know that on this journey we can never reach our destination.
To coin a phrase, for Popper’s scientific method: there is no truth only
progress. ‘Scientific certainty’ is therefore nonsense, one term contradicts
yet Popper’s scientific method has its problems. Work by other 20th Century Philosophers such as Thomas Kuhn (1962), Imre Lakatos (1970) and others
has shown that Popper’s rejection of theories can be too harsh; from a single
case that doesn’t fit, an otherwise good theory must be thrown out or modified.
There are other philosophical issues. No theory can be tested based on
observations alone. With it goes some baggage: internal assumptions about
accuracy of experimental conditions and equipment. So, we may at best falsify
the theory coupled with our auxiliary hypotheses. To determine that it is the
theory in isolation which is
falsified, we must demonstrate that the auxiliary hypotheses are true, which is
akin to using induction. This problem is often referred to as the Duhem/Quine thesis
(see Quine 1961; Duhem 1962). There is
another issue associated with hypothesis testing. Consider the example used
previously; when we look for our non-white swan, the testing process is fairly
clear cut: either the swan is white or it is not. Observation of a black swan
would falsify this hypothesis. But other hypotheses are more difficult to falsify. Consider, for example, testing
this hypothesis: that you are tossing a fair (unbiased) coin. If you throw a
long, unbroken sequence of tails, to determine if you can reject the hypothesis
you need to use probability and impose confidence intervals on the
decision-making process. We use such a procedure regularly in science, but even
with a very long sequence of tails our hypothesis of an unbiased coin at best
only becomes highly improbable (see Schilpp 1974).
And we must consider at what point it is anything other than arbitrarily appropriate
to consider it falsified under a Popperian paradigm.
Popper’s approach has been criticised as too idealistic or naive: it takes out
the very human element of science. Our innate ‘humanness’ and the limits this
imposes on our ability to interpret the world is at the very core of our
process of understanding, so it must be of first concern to us in any method we
use to gain knowledge. And yet in one sense, the very limitations with
falsificationism outlined above serve to highlight how important a
philosophical outlook is in science; scientists must be aware at a deeper level
of how we interpret the world and the implications this has on the process of
is recognised that Popper makes important inroads with his notion of rigorously
testing hypotheses and thus avoiding the obvious pitfall of induction. Yet, as
outlined above, there are some internal inconsistencies with the falsification
process associated with the Popperian assessment of theories. So we see that
Hume’s central issue with induction retains some of its sting. Further, Hume’s
problem with induction extends in a broader sense to the very method we use to
attain knowledge: there is no final
‘correct’ approach to interpreting the world. We must continue our search for a
better one than we have.
And now we may return to the
Precautionary Principle. As stated earlier, the original Rio Documentation is
unclear in its wording, using triple negatives and muddy phrasing. At the
Wingspread Conference in 1998, an attempt was made to rework the Precautionary
Principle in relation to science, but aspects of the new document are even less
clear. This is largely due to the introduction of the cause and effect concept.
However, my main point of contention here lies with the more clear-cut misuse
of this concept in subsequent policy. In the recent IUCN document, for example,
it was stated that where an environmental threat is relatively certain, strict
preventative measures should be taken. In this document, they define ‘relatively
certain’ as where a causal link between an action and environmental damage can be established (IUCN 2007). But
consider this: how can we logically apply the precautionary principle to ever demonstrate a causal link between human activities and damage to biodiversity
or natural resources?
To get a handle on the problems here,
we need to more closely examine the idea of ‘cause and effect.’ Earlier, I
mentioned David Hume’s problem of induction. In fact, this problem arose
naturally from another issue that Hume (1739) was more vocal about in his
writings: cause and effect. This was the key point in Hume’s philosophy and
remains one of his lasting impressions on us today.
Hume’s problems with cause and effect
are best introduced by an example he used himself (Hume 1739). How do we know
the sun will rise tomorrow? Because we have seen it rise on hundreds of
mornings, and have known it to do so ever since Humans have recorded their
observations; because day always follows night. But these are not logical thoughts:
they are the voice of habit and custom. There can always be an exception to the
rule; just because the sun has risen as far back as we can remember it may not
do so tomorrow. Just as day has always followed night, it may not do so
tomorrow. Consider this: from all our observations of day following night, can
we say that because night ends, the
day must follow? This is cause and effect; it is not logical (so not
scientific) and we can see that from this idea springs the problem of
induction. We will probably not lose an ounce of sleep tonight worrying whether
the sun will rise tomorrow or not; we have strong expectations that it will!
But the kernel of this idea is very important to how we may view science.
Hume (1739) found that we never
actually observe any cause and
effect. We can observe event A, and we can observe event B, bet we never
observe the ‘causal connection’ or ‘link’ between them, event C. In other
words, we see that A happens and then B happens just after it; we may see this
happen a lot of times, but it does not mean that because A happens, B happens. Our habit of making any connection
between things we see is driven by our desire to understand and find meaning in
our world; David Hume tells us that it says more about our psychology than
In science, we look for relationships
between things. One thing may be increasing as another thing increases. For
example, Human beings burn coal and this may increase amounts of carbon dioxide
in the atmosphere. There also may be a rise in average temperature around the
world. But although the pattern of rise in both carbon dioxide and temperature
may be very similar, we can never say that one causes the other. The urge to do so is driven by our desire for
explanation, to look for pattern and generalise, to make conclusions using
induction, which is not logical. So what can we do then? In modern science we can look for evidence against relationships between things, to try and find exceptions to
the rule. If we find no evidence against the relationship, then it does provide
some more corroborative evidence supporting our theory; our knowledge has
advanced, yes, but it can never be shown that humans have caused global warming.
Of course, even acknowledging that we
may lack scientific knowledge about issues such as global warming is important.
And in this sense, the precautionary principle succeeds. But we need to go
further than saying that we may not right now understand certain relationships
between increases in carbon dioxide and global temperature. We need to realise
that ultimately, we can never link these two things through observation in any
logical way. To this, some might say, who cares? As far as we should worry,
humans cause global warming; smoking causes cancer. But it is important! The
capabilities of science are overstated in the IUCN document, and if both the
public and scientists do not think so, then science is weakened through
confusion and ignorance. And this means any application of science (such as
sustainable restoration of our planet’s ecology) must also be weakened. We can
never be certain, about relationships between things or about a final answer to
our questions. There will never be a
time or place where ‘cause and effect can be established’ because this requires
a demonstration of the link between two conjunctive events and such a link can
never be observed. As it stands then, the IUCN policy promises something
undeliverable. It proposes something unmanageable. Until we rethink what we can
expect of science, and the implications this might have, we cannot most wisely
move forward in either science itself or areas where it is applied.
I am not saying there has
not been great value added by the work of the many researchers in this area
from within law, science and economics. Nor am I saying that we shouldn’t keep
pursuing a clearer understanding of the nature of science and practically apply
it in risk analysis and management. To the contrary, these problems are
precisely too important not to apply science appropriately in trying to find
sustainable solutions. But first and foremost, there is a basic
misunderstanding in the wording of the IUCN document in regard to science that
has apparently not been recognised; it is more than unclear, it misleads.
Now, a good thing about the
precautionary principle is that we are more cautious about undertaking
activities which may lead to harming ourselves or the environment. We have
power to enforce the law and protect the environment, although we may struggle
to be consistent. I am certainly not saying that by changing the words of such
documents we will solve the sustainability crisis. This is far too simplistic.
But I think the way the recent IUCN statement has been worded shows that we are
generally not thinking carefully enough about what science can bring to the
may seem a subtle point, but it is fundamental, with profound implications.
First, policy implementing the Precautionary Principle (such as the IUCN
document) is used as a template for all we can achieve in sustainable
management; if our reference documents are misleading, then errors will be
compounded and our efforts stymied. Second, by overstating what science can
achieve and ignoring the underlying philosophy we become complacent. This is a
natural, human frailty; even though we may superficially acknowledge science as
uncertain, we gradually are eroding the keen edge of science because we
subconsciously view our current ideas with more permanence than they deserve.
because they are ‘our’ ideas, we stubbornly refuse to question the validity of
a lifetime of research. A clearer understanding of the philosophy underlying
all that we do in our work will constantly guard against this. Through deeper
questioning, we create a keener front on our attempts to understand the world.
Third, the example I have used here is the tip of the iceberg; there are a
range of other areas in science, all of them underpinned by philosophy. The
work of philosophers stretching across the last 2,500 years is distilled to
purified essence within modern science; it implicitly underlies how we do what
we do, today. Through more effort in understanding this volume of work, we can
be better scientists. But by shying away from these philosophical issues, we
ultimately limit our scientific achievements. This has a flow-on effect in
questions of sustainable management, where science must play a vital role and
be clearly defined.
Although since the time of
it has been ever
more tempting to think so, science is not flawless, no less because human
beings, with their limited perceptions and human frailties, are its masters.
Instead, it has boundaries, a major one being the impossibility of finding any
final answer to the questions we ask. But when we fully accept this, rather
than it inspiring any sense of futility, despair or frustration, there is,
instead, hope, and merit in recognising our ignorance. In throwing our
successes and failures in a bolder, brighter searchlight, we switch on a
philosophy of open-minded humility, to give and take criticism, and we
recognise at last, deep down, that our knowledge is never final.
Many scientists are forgetting, in the
rush to specialise, pigeonhole and publish, to stop and ask these broader
questions. We shy away from this deeper philosophical thought because it
appears messy in our ordered world, pointless or confusing, endless. But it is
only through such thinking that scientists can explore all the possibilities
and understand the limits to human understanding. We can then better nest our
ideas within the web of sustainability, where science and society meet. In the
process, we may realise our ideas are not so clear-cut or well-defined as we
think; this is valuable! A messy middle road will wind forth, but we shouldn’t
in ignorance separate ourselves out of our very human need for security, or
fear of the unknown, all the while reaching for the supporting crutch of truth.
For, in a wonderful and liberating sense, so much remains unknown; and our
final answer is unknowable. Only once we embrace this ‘truth’ will we see our
limitations, and then more clearly our possibilities. And we can take this
philosophy forward to better face humanity’s most urgent question: how can we
secure a sustainable future?
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