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                                            Theory of Knowledge

If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.

Edward O Wilson

There are plenty of opportunities to explore the theory of knowledge within ESS. The systems approach used throughout ESS is diflerent from traditional models of scientific exploration. This allows us to compare the two approaches to understanding. Conventional science tends to use a reductionist approach to looking at scientific issues, whereas the systems approach requires a holistic understanding.


While the systems approach is frequently quantitative in its representation of data, it also addresses the challenge of handling a wide range of qualitative data. This leads to questions about the value of qualitative versus quantitative data. There are many checks and guidelines to ensure objectivity in quantitative data collection and handling in the purely physical sciences, but these standards of objectivity are more diflcult to rigorously control in ecological and biological sciences. In addition, ESS

is a transdisciplinary subject, the material addressed often crosses what may seem to be clear subject boundaries (e.g. geography, economics, and politics).

The systems approach allows comparisons to be made across disciplines, and the value and issues regarding this are discussed throughout the course and in this book. In exploring and understanding an environmental issue, you must be able to integrate the hard, scientific, quantitative facts with the qualitative value-judgements of politics, sociology and ethics. All this makes particularly fertile ground for discussions related to theory of knowledge.

Whoever undertakes to set himself up as a judge in the field of Truth and Knowledge is shipwrecked by the laughter of the gods.


Albert Einstein\=]


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Thomas Edison

Care for the planet – it’s the only one we have

Chance favours the prepared mind.

Louis Pasteur

We see only what we know.

Johann Wolfgang von Goethe

Is knowledge all you need?

Can too much knowledge be a bad thing?

Throughout this book, ToK boxes contain advice and information relating to this aspect of the course. This chapter looks in more detail at ways in which ToK can be applied in specific parts of the syllabus.


                   1 Foundations of environmental systems and societies

This topic covers the concepts that are central to the ESS course, namely the systems approach, models, equilibrium, sustainability and pollution.

Throughout Chapter 1, relevant ToK ideas are raised at appropriate parts of the text.

Environmental value systems (EVSs) are influenced by education, family, friends, culture and other inputs from the society we live in. These EVSs influence how we see the world and respond to it. This topic oflers many opportunities to discuss the interaction between EVSs and societies’ responses to the environmental issues covered in the course.

Many of the strategies proposed during the course to tackle environmental concerns have alternative

options. Experts sometimes disagree about pollution management strategies, for example — how do

we decide which strategy is best, and on what


basis might we decide between the judgements of the experts if they disagree? How do we decide

between alternative perspectives, and can any one management strategy be considered as final?


Case study

Holism versus reductionism

The emphasis in this course is on understanding the sum of the parts of a system (i.e. a holistic approach) rather than considering the components separately. This contrasts with the reductionist approach of conventional science. Data

collection is involved with measuring the inputs and outputs of a system, and processing the data reveals understanding of the processes within the system. The main difference between the systems approach and conventional science is that the former describes patterns and models of the whole system, whereas the latter aims at explaining cause-and-effect relationships within it. Is one approach better than the other, or is it a matter of perspective as to which approach brings real benefits in understanding?

All models are wrong, but some are useful.

George Box (innovator in statistical analysis)












Advantage of holism

The advantage of the holistic approach in environmental science is that it is used extensively in other disciplines, such as economics and sociology, and so allows integration of these diflerent subjects in a way that would not be possible (or at least not so easy) in conventional science.

Shall I refuse my dinner because I do not fully understand the process of digestion?

Oliver Heaviside


As systems are hierarchical, what may be seen as the whole system in one investigation may be seen as only part of another system in a diflerent study (e.g. a human can be seen as a whole system with inputs of food and water and outputs of waste, or as part of a larger system such as an ecosystem or a social system). Diflculties may arise at where the

boundaries are placed, and how this choice is made.

The strongest arguments prove nothing so long as the conclusions are not verified by experience. Experimental science is the queen of sciences and the goal of all speculation.

Roger Bacon

Reductionism is a dirty word, and a kind of ‘holistier than thou’ self-righteousness has become fashionable.

Richard Dawkins















Environmental value systems

There are assumptions, values and beliefs, and worldviews that aflect the way in which we view the world. These are influenced by the way we are brought up by our parents, our education, the friends we have, and the society we live in. This

course should have helped you to appreciate what your personal value system is, where it lies in a spectrum of other worldviews, and have enabled you to justify and evaluate your position on a range of environmental issues.

The great end of life is not knowledge but action.


Thomas Huxley

We know what we are, but know not what we may be.

William Shakespeare


                               2 Ecosystems and ecology

This topic gives scope for discussion on how ecological relationships can be represented by diflerent models, such as food chains, food webs, and ecological pyramids. How can we decide when one model is better than another? Ecosystems

and ecology also allow exploration of the benefits of the systems approach, and how ecological research compares to investigations in the physical sciences (e.g. physics and chemistry). For example, a reductionist approach looks at the individual parts of a system: this approach is usually used in traditional scientific investigations; a holistic approach looks at how the parts of a system work together as a whole: this approach is usually used in modern ecological investigations.
















How would you evaluate your personal standpoint about the environment and the issues raised throughout the course?















Global cooperation is needed to tackle many environmental problems, and to ensure a sustainable future for all. We hold the future in our hands.

If facts are the seeds that later produce knowledge and wisdom, then the emotions and the impressions of the senses are the fertile soil in which the seeds must grow.

Rachel Carson

Students on an ecology field trip are instructed on sampling techniques.

Ecological research applies techniques that aim to remove subjectivity (e.g. the randomized location of quadrats when studying the distribution of species in a habitat rules out site-selection by the researcher). The interpretation of data, however, is

open to interpretation and personal judgement. It has been said that historians cannot be unbiased: could the same be said of environmental scientists when making knowledge claims?






















Sampling freshwater invertebrates in a lake

I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind.


Lord Kelvin

No eflect that requires more than 10 per cent accuracy in measurement is worth investigating.

Walther Nernst


Ecology provides many opportunities to explore issues regarding the reliability and validity of data and how it is collected. It also addresses the pros and cons of subjective as opposed to objective data.

Nevertheless, the interpretation of data – even of objective data – is open to widely diflerent viewpoints (see the case study ‘A matter of interpretation’).


Ecology relies on the collection of both biotic and abiotic data. Abiotic data can be collected using instruments that avoid issues of objectivity as they directly record quantitative data. The measurement of the biotic (or living) component is often more subjective, relying on your interpretation of diflerent measuring techniques to provide data. It  is rare in environmental investigations to be able



Setting up a transect to study succession on a shingle ridge

Can we substitute space for time? Is space (and spatial change) a surrogate for time (and temporal change)? In studying succession, we use spatial changes to make inferences about temporal changes. Should this be

allowed? Succession may be affected by external factors, such as global warming.

to provide ways of measuring variables that are as precise and reliable as those in the conventional (i.e. physical) sciences. Working in the field means that variables cannot be controlled, only measured, and fluctuations in environmental conditions can cause problems when recording data. Standards of acceptable margins of error are therefore diflerent.

Will this aflect the value of the data collected and the validity of the knowledge?

Applying the rigorous standards used in a physics investigation, for example, would render most environmental studies unworkable, and we would miss out on gaining a useful understanding of the environment.


Field workers measuring the diameter of trees at breast height (DBH) to assess the recovery of tropical rainforest following logging in Borneo.


  1. Which are the three most productive ecosystems in terms of NPP?

    • tropical rainforest               2.2

    • tropical deciduous forest    1.6

    • estuaries                             1.5

  2. Which are the three most productive ecosystems in terms of NPP per unit of biomass?

    • continental shelf                 360 kg m–2 yr–1 per kg m–2

    • open oceans                        40 kg m–2  yr–1  per kg m–2

    • estuaries                             1.5 kg m–2  yr–1  per kg m–2

    • deserts                                1.5 kg m–2  yr–1  per kg m–2

  3. How do you explain the differences between your two answers?

Much of the biomass of a forest is woody, non- photosynthesizing material. This means it is non-productive, thus the NPP per unit of biomass is low.

Now there is one outstandingly important fact regarding Spaceship Earth, and that is that no instruction book came with it.

Buckminster Fuller pragmatic approach is called for in ecological studies, but this leaves the subject open to criticism from physical scientists regarding the rigour with which studies are done. Is some understanding better than no understanding at all?

Controlled laboratory experiments are often seen as the hallmark of the scientific method, but are not possible in fieldwork—to what extent is the knowledge obtained by observational natural experiment less scientific than the manipulated laboratory experiment?


                              3 Biodiversity and conservation

This topic oflers the opportunity to discuss what is meant by the term ‘biodiversity’. Diversity indices are not absolute measures in the same way that temperature is, for example. Diversity indices involve a subjective judgement on the combination of two measures – proportion and richness.


Diversity measures are sometimes misread, or confused with species richness (pages 138–140). This can have implications for the way in which the impacts of human disturbance are interpreted.


This topic also oflers diflerent perspectives on species and habitat conservation. Which strategy is best for conservation, and how do societies decide the best approach? How do we know when critical points are reached, beyond which damage to ecosystems and biodiversity may become irreversible (e.g. leading to species extinction)? Should the people who cause environmental damage be held morally responsible for the long-term consequences of their actions?

One further topic for discussion is the diflerent views people have on the origin of life on Earth. The established scientific explanation is that all species have evolved through the process of natural selection, although other people take alternative views.


Evolution versus creationism

What constitutes ‘good science’ and what makes a ‘good theory’? Can we have confidence in scientific theories that rely on indirect evidence and that happen over such long periods of time as to make testability a problem?

In 1859, Charles Darwin’s book On the Origin of Species revolutionized biology and the way it is studied. Despite this, some people still refute its claims: one such group are the creationists, who believe in the literal truth of the biblical Genesis story. Can their views be reconciled with the scientific evidence?

What do their views say about the scientific method and what constitutes good science?

Mark on this grid where your opinions lie in terms of the truth of creationism and evolution.


Creation                                                                             Evolution




Creationist claims

1Is evolution scientific?
  • Evolution within a species can be tested and is well established, but doesn’t explain the creation of species.

  • If evolution occurs over millions of years, it is untestable and therefore unscientific.

2Evolution contradicts physics
  • Physics, second law of thermodynamics: The entropy (disorder) in a system will always increase over time.

  • Evolution: Life appears from disorder, becoming increasingly ordered and complex over time.


Is this true for all science?

Is evolution by natural selection a testable theory? Are there organisms that are suitable for experimentation to see natural selection in operation?

Fossilized allegedly human tracks with a trail of typical dinosaur tracks, in the same rock layer.

  • Science concerns testable ideas.

  • Science therefore focuses on recurrent, repeatable events.

  • Radio-isotope dating is the basis for almost all estimates of evolutionary time. It was applied in 1986 to lava from Mt St Helens, which erupted in 1980, and produced dates of millions of years ago. Since the dating is almost a million times too old, dating of fossils must likewise be a million times too old.





These metatarsal (heel-impressed) dinosaur tracks in the Cretaceous limestone of the Paluxy River, near Glen Rose, Texas, were once considered by many creationists to be human tracks together with a trail of typical dinosaur tracks. It was thought that this was evidence for humans and dinosaurs living together before Noah’s flood.

Neither science nor maths can ever be complete.

Kurt Gödel

Re-assessing the creationist argument

1 Distortion
  • The second law of thermodynamics is true as quoted but it only applies to isolated systems. Life is part of a system in which entropy does increase samples taken from the dome were divided into subsets containing different minerals and each tested for radioisotopes



Potassium/argon dating of the volcanic dome formed by lava at Mt St Helens


  • The key ‘missing link’ fossils – intermediates between major groups – are still missing.

  • Archaeopteryx – the famously feathered reptile – has been debunked as a fake, along with ‘Piltdown man’ and many others.

4Key creationists in science
  • Physics – Newton, Maxwell, Kelvin

  • Chemistry – Boyle, Dalton, Ramsay

  • Biology – Linnaeus, Mendel, Pasteur

  • Astronomy – Copernicus, Galileo, Kepler, Herschel

  • Mathematics – Pascal, Leibnitz. 5 Common sense

  • The idea that we were created via a purely random

process of mutation ...

... is statistically absurd

... contradicts the obvious signs of design all around us

... denies humanity: it allows no meaning for creativity, love, or purpose

... just gives selfish people the justification to act without regard for morality.


Ignorance more frequently begets confidence than does knowledge: it is those who know little, not those who know much, who so positively assert that this or that problem will never be solved by science.

Charles Darwin

If you were to re-assess your view of which was true, creationism or evolution, based on belief in the arguments expressed above, where would you mark the grid?

Creation                                                                                                           Evolution

  • Mutation is indeed random, but natural selection is not, so it can work cumulatively to bring about apparent design.

  • Evolution by natural selection can be demonstrated in organisms with short generations (MRSA bacteria is an example).

2Highly selective use of data
  • For every creationist scientist mentioned, hundreds, even thousands of others are not. Moreover, scientists who pre-date evolutionary theory cannot be called creationists since there was no creationist/evolutionist argument at that time.

  • Huge areas of evolutionary data are completely ignored:

    • homologous structures

    • biogeographical evidence

    • molecular evidence (e.g. DNA)

    • embryological evidence.

3Disinformation and misinterpretation
  • Archaeopteryx is widely accepted as authentic by the scientific community; there is no basis for its ‘debunking’.

  • We now understand, from dedicated work in the 1980s, how the tracks at Paluxy River were

formed. Dinosaur footprints normally recognized as such were created by dinosaurs walking or running on their toes (these are the deep three- toed tracks, called digitigrade tracks). Dinosaurs walking on their soles or heels (metatarsal bones) create diflerent impressions called metatarsal tracks which are longer than the digitigrade ones. Unlike digitigrade tracks, metatarsal tracks may look superficially like human tracks after erosion or if mud-movements followed formation of the track.


  1. Who should set the limits for fish yields? Justify your answer.

  2. Who should decide on common management? Justify your choice. Who would suffer as a result of this choice?

Potassium/argon dating of the volcanic dome formed by lava

at Mt St Helens

Archaeopteryx – a link between reptiles and birds

Metatarsal impressions are not the only reasons for creationists misinterpreting the tracks at Paluxy River. Several other phenomena have also been mistaken for human tracks including erosional features and some carvings on loose stone blocks. To learn more about the Paluxy River site, go to, enter the book title or ISBN, and click on weblink 


















Many species living today are intermediates between other groups (see Richard Dawkins’ book The Greatest Show on Earth for extensive evidence). It is not true that evidence for missing links is absent (see photos).





















A 47-million-year-old fossil (named Ida, top) seems to be a link in primate evolution, bridging the evolutionary split

between higher primates such as monkeys, apes, and humans and their more distant relatives such as lemurs (lower photo).


4Hype and spin
  • Some real concerns about isotope dating voiced by scientists are hyped up to make the whole process appear void.

  • Sensible explanations of anomalous results (e.g. for Mt St Helens) are spun as ‘desperate evolutionists patching up a defunct theory’.

5Learn to live with uncertainty
  • There is much uncertainty in both science and faith.

  • Doubt and questioning are creative.

  • In science, uncertainty leads to new ideas.

  • In faith, too, doubt can lead us to ask new questions and find new meaning.

  • At the same time, you need to know what your core values are.

6Learn to spot ‘pseudo-science’


Good science

  • shows fixed ideas (dogma)

  • shows willingness to change

  • selects favourable findings

  • accepts and attempts to explain all findings

  • does not have peer-review

  • has ruthless peer-review

  • is unable to predict

  • has predictive power

  • has unverifiable claims

  • is experimentally verifiable

  • has a hidden agenda

  • makes few assumptions

  • lacks consistency

  • is usually consistent




How should we decide what to protect?

Humans make judgements about the natural world, and the ways in which it can be protected. Do species have an intrinsic right to exist even if they are of no economic value at the moment? Should as much as possible of the environment be protected, or do we need more pragmatic approaches based on realistic expectations?

How do we justify the species we choose to protect?

Is there a focus on animals we find attractive? Is there a natural bias within the system? Sometimes the choices we make are based on emotion rather than reason: does this affect their validity?


Case study

How should we decide what to protect?

Humans make judgements about the natural world, and the ways in which it can be protected. Do species have an intrinsic right to exist even if they are of no economic value at the moment?

Should as much as possible of the environment be protected, or do we need more pragmatic approaches based on realistic expectations?

How do we justify the species we choose to protect?

Is there a focus on animals we find attractive? Is there a natural bias within the system?

Sometimes the choices we make are based on emotion rather than reason: does this affect their validity?

People are not going to care about animal conservation unless they think that animals are worthwhile.

David Attenborough


















Cheetahs have a very small gene pool with little genetic variation. They are especially prone to changes in their environment or the outbreak of disease. Should we focus conservation on species which are more resilient and more likely to survive into the future?







Archbishop James Ussher (1581–1656), Church of Ireland (protestant) Bishop of Armagh, claimed to have established the date the Earth was formed as Sunday 23 October, 4004 BC whereas the evolutionist approach now puts the Earth as at least 4.5 billion years old.

Extraordinary claims require extraordinary evidence.

Carl Sagan

Do tigers have a greater right to exist than endangered and endemic species of rat?

The nation behaves well if it treats the natural resources as assets which it must turn over to the next generation increased, and not impaired, in value.

Theodore Roosevelt



Describing species

Historically, taxonomists (scientists who describe new species) focused on groups that interested them. These tend to be the larger more attractive groups (e.g. mammals, birds, flowering plants). Is there

a bias in the way in which species are described? What about small and more obscure groups (e.g. nematodes) or smaller organisms that are diflcult to collect and identify, or which have not attracted scientific attention? What impact does this have on estimations of the total number of species on the Earth? Can we reliably comment on species’ extinction rates?




Most of the species of animals on the planet are beetles. Do you think the number of described species reflect this? What type of organisms have scientists historically focused attention on?

              4 Water, aquatic food production systems, and societies

Topic 4 provides the opportunity to discuss the value and limitations of models. The hydrological cycle is represented as a systems model: to what extent can such diagrams eflectively model reality, given that they are based on limited observable features?

Water scarcity around the globe raises the issue of how aid agencies often use emotive advertisements to promote their cause. To what extent can emotion be used to manipulate EVSs and the actions that follow on from them? Do the ends justify the means?

Many societies have traditions of food production that may go against our own EVS. The Inuit people, for example, have an historical tradition of whaling – something that would go against the EVS of many, if not most, societies. To what extent does our culture determine or influence our ethical judgements?

Inuit whale hunting off the coast of Alaska


Topic 4 also looks at how water quality can be tested. A wide range of parameters are used to test the quality of water, but to what extent can scientists be sure that they have correctly identified cause-and- eflect relationships (e.g. that pollution directly aflects species diversity in a stream), given that they can only ever observe correlation?


Case study

The Tragedy of the Commons






















Fishing net catch, North Sea

Renewable resources, such as fish, need not be depleted provided that the rate of use does not exceed maximum sustainable yield. In other words, if the rate of use is within the limit of natural replacement and regeneration. If resources become over-exploited, then depletion and degradation will lead to scarcity. If more than one nation is exploiting a resource, which is clearly the case in the fishing industry, resource degradation is often the result.

Garrett Hardin (1968) has suggested a metaphor, the ‘Tragedy of the Commons’, to explain the tendency: this refers to the way that there may be little control over the way common resources are used, and the selfish acts of a few individuals can destroy the resource for others.


In any given ocean, a number of nations may be fishing. Apart from the seas close to land, where there is an Economic Exclusive Zone, no country owns the oceans, or the resources that they contain. But countries may use the resources. If one country takes more fish from the oceans, their profit increases. However, other countries do not benefit from this. To maintain the same relative profitability, other countries may increase their catch, so that they are not losing out relative to their competitors.


The ‘tragedy’ is that other countries feel compelled to increase their catch, to match the catch of the one that initially increased its catch. Thus, the rate of use may exceed maximum sustainable yield and the resources become depleted.

Although simplistic, the Tragedy of the Commons does explain the tendency to over-exploit shared resources and the need for agreements over common management.

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