Theory of Knowledge Natural Sciences

Guiding questions What does it mean for a discipline to be a science? Is there just one scientific method? Should there be ethical constraints on the pursuit of scientific knowledge?

Natural sciences The natural sciences seek to discover laws of nature— regularities in the natural world. These are often causal relationships of the form “if X happens then Y will be the result”. This description implies that there is an attempt to produce a system of knowledge that is independent of human agency. Whether this is indeed possible is a matter of debate. The methods of the natural sciences based on observation of the world as a means of testing hypotheses about it are designed to reduce the effects of human desires, expectations and preferences, in other words they are considered objective.

In this sense, the natural sciences emphasize the role of empirical inquiry: scientific knowledge must be able to withstand the test of experience and experiment. One interesting area of discussion is what differentiates the scientific from the non-scientific. Many would suggest that it is the methods used in science. It is therefore interesting to consider what it is about these methods that mean that the knowledge they generate is often regarded as more reliable than those employed by other AOKs.

Introduction The story of the natural sciences is a story of remarkable achievements. The scientific revolution of the 17th century initiated a period of tremendous progress. The extraordinary success of the natural sciences has led some people to see them as the dominant cognitive paradigm or model of knowledge. Some people have argued that science is the only road to knowledge. We should be cautious about some of the more extravagant claims that are made on its behalf. How far do the natural sciences give us certainty?

Natural sciences do not have a monopoly on the truth Some critics of science have drawn attention to the dangers as well as the benefits of scientific knowledge. The benefits of science outweigh the costs. What is the nature and the status of scientific knowledge? Why is it important to distinguish between science and non-science? Science and values

Science and pseudo-science The natural sciences typically denote subjects like physics, chemistry and biology. Charlatans may describe dubious medicines and remedies as scientific in order to deceive gullible people. Acupuncture, astrology, creationisme, crystology, feng shui, graphology, homeopathy, phrenology,… We should be open-minded about some of the above beliefs. Why do they work? It involves formulating hypotheses and conducting controlled experiments to test them. Just because someone says that something is scientific does not mean that it is scientific We need criteria to distinguish genuine science from pseudo-science Just because something is not a science does not mean that it is a pseudo-science What distinguishes a pseudo-science is that it claims the status of science while lacking its substance

The difference between science and pseudo-science Scientific hypotheses are testable, pseudo-scientific are not Vagueness Ad hoc exceptions For a hypothesis to be genuinely scientific it must be testable It is clearly stated and makes precise rather than vague predictions It does not keep making ad hoc exceptions when it comes across counter-examples

The scientific method What distinguishes science from non –science is a distinctive method According to inductivism, science consists of 5 steps Observation and classification of the relevant data Hypothesis are formulated based on patterns in the data Experiment to test the prediction (controllability, measurability, repeatability) Law is discovered if the experimental results confirm the hpothesis Theory explains and unifies various laws in terms of some underlying principles

Example: the Copernican revolution Observation: Ptolemy (85 – 165) Hypothesis: Copernicus ( 1473 – 1543) Prediction: Galileo (1564 – 1642) Law: Kepler (1571 – 1630) Theory: Newton (1642 – 1727)

Scientific progress needs a background of careful observation Technology can extend our powers of observation Imagination plays an important role in the development of new scientific ideas Methematics also plays a central role in the development of scientific ideas Many scientific discoveries are counter-intuitive and go against untutored common sense

Problems with observation Problem of relevance: it is always possible that we have overlooked a factor that later turns out to be relevant Expectations: our expectations influence what we see Expert seeing: the use of scientic equipment to make observations can complicate things The observer effect: the act of observing can sometimes affect what we observe

Testing hypothesis Confirmation bias: people tend to look for evidence that confirms their beliefs and overlook evidence that goes against them. Exemples Darwin and Mendel Background assumptions: whenever we test a hypothesis, we make various background assumptions, any one of which could turn out to be false Many different hypotheses are consistent with a given set of data: it is in practice impossible to prove that any particular hypothesis is true The principle of simplicity: given 2 competing theories which make exactly the same predictions the simpler theory is to be preferred. In practice, aesthetic considerations are likely to play a role in a scientist’s choice of hypothesis

The problem of induction Inductive reasoning goes from the particular to the general and plays a central role in the way that scientists think When we reason inductively we are moving from the observed to the unobserved Practical problems: how many observations should we make before we are entitled to make a generalisation? Even very well-confirmed hypotheses can sometimes turn out to be wrong Theoretical problems: science is supposed to be an empirical discipline which makes no claim beyond what has been observed

Falsification Karl Popper (1902 – 1994) Distinction between genuine science and pseudo-science A genuine scientific theory puts itself at risk Conjectures and refutations: there is no mechanical way of coming up with good hypotheses on the basis of the observational data. Confirmation is tentative and cannot prove that a law is true. Refutation is decisive. A properly scientific approach to a subject should explore the shortcomings of currently accepted theories Any theory that resists our best efforts to falsify it should be provisionally accepted as the best we have for the time being

Criticisms of Popper Falsification is conclusive in theory but not in practice (Newton, Mendeleyev, Darwin) Auxiliary hypotheses can rescue a falsified theory (Newtonian physics) The rationalist strand in scientific thinking

Science and society Thomas Kuhn (1922 – 1996) Paradigm: overarching theory shared by a community of scientists Normal science: the vast majority of scientists solve problems within a paradigm while taking the paradigm itself for granted Scientific revolutions: occur when scientists become dissatisfied with the prevailing paradigm If a new paradigm provides a better explanation of things, a scientific revolution can occur with the danger of scientific crisis How rational is science? Problem of priority dispute, social context, military or business interests

Assessment of Kuhn’s position Normal science: if scientists never question their asumptions (the paradigm), their beliefs may end up into dogmatism Scientific revolutions: scientific knowledge is cumulative and over time getting closer to the truth. Theories are more or less inclusive Choosing between rival paradigms: importance of judgement, self-correction, natural competitiveness and evidence.

Science and truth A theory of everything?: it seems unlikely that the map of science will ever be able to reproduce the territory of reality Science and scientism: science is the only way we can make sense of reality and discover the truth (Rudolf Carnap). Science is a fallible human enterprise which may get us closer to the truth but can never give us certainty

Team debate: ‘Science does more harm than good to society.’

Conclusion

Key points The success of the natural sciences has led some people to see them as the most important form of knowledge The main difference between science and pseudo-science is that scientific hypotheses can be tested and pseudo- scientific ones cannot According to the traditional picture of the scientific method, science consists of five key steps: observation, hypothesis, experiment, law, theory Among the problems that arise in applying the scientific method are that observation is selective, and that you are more likely to notice things that confirm your hypothesis than those that contradict it Since scientific laws are based on a limited number of observations, we can never be sure that they are true

According to Karl Popper, science should be based on the method of conjectures and refutations, and scientists should try to falsify hypotheses rather than verify them In practice, a hypothesis can no more be conclusively falsified than it can be conclusively verified Thomas kuhn drew attention to the role played by paradigms in science and argued that the history of science is punctuated by revolutionary jumps or “paradigm shifts” Although scientific beliefs change over time, it could be argued that each new theory is closer to the truth than the previous one Despite the success of the natural sciences, they cannot give us absolute certainty and there are many perplexing questions that lie beyond their scope

Scope and applications What is the social function of the natural sciences? How many different forms does it encompass (eg physics, chemistry, geology, biology, etc.)? What are their separate aims? To what extent are natural sciences influenced by the society and culture in which they are pursued? How important are the natural sciences?

Natural sciences is a system of knowledge of the natural world largely based on observation and constructed using reason and imagination The sciences are shared knowledge, often shared by a large grouping geographically spread and largely independent of culture Prediction is often an important feature of scientific knowledge but understanding is also a prime purpose Natural sciences are interested in producing generalized statements about the natural world, principles or scientific laws Most of these laws are causal: if event A happens then event B will happen as a result

Concepts and language How do we use language to express the knowledge found within natural sciences? To what extent does this differ according to different forms of natural sciences? Are there any central concepts for which we need specific language before approaching natural sciences?

Many of the laws of the natural sciences are stated using the language of mathematics – maths is central Language of the sciences is precise in order to eliminate ambiguity which might affect the reasoning process

Methodology Which ways of knowing do we use in order to connect with, and understand, natural sciences? Which ways of knowing do the natural scientists themselves use in order to study natural sciences and communicate their understanding of it?

Measurement involves interaction with the world which changes it Models are important in most areas of the natural sciences Classification is a central idea in many of the natural sciences Among the methods employed by the natural sciences are: hypothesis, deduction and induction – use of reason and sense perception

Historical development How has our understanding and perception of natural sciences changed over time? How has the role of natural sciences within society developed? To what extent has the nature of natural sciences (for example, the different forms of natural sciences) changed? What relationship do today’s natural sciences have with those of the past?

There have been a number of pivotal shifts of thinking in the development of the natural sciences

Links to personal knowledge To what extent are you involved with natural sciences? How is your perception of the world, and your position in it, affected by natural sciences?

The natural sciences give us a view of ourselves as material entities behaving according to universal laws Perhaps little space here to see ourselves as rational, free agents with desires and the ability to choose Individuals have contributed to scientific progress, often in revolutionary ways Use of imagination, intuition and emotion in creation of hypothesis