1.3 Duhem & Kuhn

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来自 The University of Edinburgh 的课程

Philosophy and the Sciences: Introduction to the Philosophy of Physical Sciences

331 个评分

The University of Edinburgh

Philosophy and the Sciences: Introduction to the Philosophy of Physical Sciences

331 个评分

What is the origin of our universe? What are dark matter and dark energy? This is the first part of the course 'Philosophy and the Sciences', dedicated to Philosophy of the Physical Sciences. Scientific research across the physical sciences has raised pressing questions for philosophers. The goal of this course is to introduce you to some of the main areas and topics at the key juncture between philosophy and the physical sciences. Each week we will introduce you to some of these important questions at the forefront of scientific research. We will explain the science behind each topic in a simple, non-technical way, while also addressing the philosophical and conceptual questions arising from it. We’ll consider questions about the origin and evolution of our universe, the nature of dark energy and dark matter and the role of anthropic reasoning in the explanation of our universe. Learning Objectives Gain a fairly well-rounded view on selected areas and topics at the intersection of philosophy and the sciences Understand some key questions, and conceptual problems arising in the natural sciences. Develop critical skills to evaluate and assess these problems. Suggested Reading To accompany 'Philosophy and the Sciences', we are pleased to announce a tie-in book from Routledge entitled 'Philosophy and the Sciences for Everyone'. This course companion to the 'Philosophy and the Sciences' course was written by the Edinburgh Philosophy and the Sciences team expressly with the needs of MOOC students in mind. 'Philosophy and the Sciences for Everyone' contains clear and user-friendly chapters, chapter summaries, glossary, study questions, suggestions for further reading and guides to online resources. Please note, this companion book is optional - all the resources needed to complete the course are available freely and listed on the course site.

从本节课中

What is this thing called science? (Michela Massimi and Duncan Pritchard)

Introduction to philosophy of science: the nature of scientific knowledge, the debates about the scientific method and the problem of underdetermination.

1.2 What is Science?14:11

1.3 Duhem & Kuhn8:02

与讲师见面

Professor Michela Massimi
Full Professor
Philosophy
Dr. Alasdair Richmond
Dr.
Philosophy
Dr. Suilin Lavelle
Lecturer in Philosophy
University of Edinburgh
Dr David Carmel
Lecturer
Psychology
Dr Mark Sprevak
Senior Lecturer
School of Philosophy, Psychology and Language Sciences
Professor Duncan Pritchard
Professor of Philosophy
University of Edinburgh
Professor Andy Clark

School of Philosophy, Psychology and Language Sciences
Professor John Peacock
Professor of Cosmology
Institute for Astronomy
Professor Barbara Webb

School of Informatics
Dr Kenny Smith

School of Philosophy, Psychology & Language Sciences
Dr Peggy Series

Institute for Adaptive and Neural Computation
Louise Connelly
E-Learning Developer
University of Edinburgh

Before the philosopher of science, Karl Popper, developed falsificationism as

a possible method of science, at the turn of last century the French physicist and

philosopher Pierre Duhem had already made an important discovery.

Namely, that scientists never test hypotheses in isolation, but always with

a set of other hypotheses, both main theoretical hypotheses and auxiliary ones.

Consider for example Newton's Law of Gravity.

We never test Newton's Law of Gravity by itself, but

always in conjunction with a set of hypotheses.

Some of those hypotheses are main theoretical hypotheses,

for example, Newton's Three Laws of Motion.

Others are auxiliary hypotheses, for example

the hypothesis about the number of planets in the solar system, their masses,

whether gravitational attraction among planets is weaker than

the attraction between the sun and the planets, and so on.

Now, suppose that from this set of hypotheses

we go on and deduce a piece of evidence,

and suppose that we look for this piece of evidence in nature, but we can't find it.

How should we interpret this negative result?

Well clearly something has gone wrong with one of our hypotheses.

But we don't know which among all those possible hypotheses is responsible for

the negative piece of evidence.

So, whenever we encounter a piece of negative evidence,

we actually don't know whether the piece of negative evidence is evidence against

one of the main theoretical hypotheses, say one of Newton's three laws of

motion, as opposed to being an evidence against the auxiliary hypotheses,

for example the number of planets in the solar system.

This is what philosophers of science call the problem of

undetermination of theory by evidence.

Very often our experimental evidence is not enough, is not sufficient to

determine the choice between tweaking or modifying one auxiliary

hypothesis as opposed to replacing altogether a main theoretical hypothesis.

And this is an important topic to which we will go back

in the session on dark matter and dark energy in cosmology.

But before we finish this introduction, I want to mention one more philosopher of

science whose work has been hugely influential in the field.

Thomas Kuhn's seminal 1962 book entitled 'The Structure of

Scientific Revolutions' changed our way of thinking about science.

Kuhn began his career as a physicist,

and from physics he moved to history of science,

where he had the chance to engage with outmoded lines of reasoning,

for example, Ptolemaic astronomy.

And by reflecting on these sort of signs,

Kuhn came to the conclusion that probably science doesn't have a distinctive method,

no matter whether it's inductive or deductive,

and that probably also we need to rethink the notion of progress in science, and

how science is meant to deliver true theories,

theories that capture exactly the way the world ought to be.

So, how did Kuhn change our image of science?

Before Kuhn, philosophers of science had a certain picture of how science grows and

unfolds based on a sequence of scientific theories each of

which were supposed to build on its predecessor and improve on its

predecessor by delivering a more accurate or more likely to be true image of nature.

But according to Kuhn this picture is totally wrong.

If we look at the history of science, if we look at the actual scientific evidence,

we obtain a radically different image of how science grows and unfolds.

According to Kuhn, science goes through periods of normal science,

crisis, and scientific revolutions.

In periods of normal science, scientists work within a scientific paradigm.

This is the expression that Thomas Kuhn introduced in 1962.

Kuhn didn't define exactly what a scientific paradigm is, but

roughly a scientific paradigm includes the main scientific theory,

the experimental and technological resources and those

by the community at the time, as well as the system of values of the community.

So, the kind of value like simplicity, mathematical elegance, parsimony and

others that scientists deem valuable.

During periods of normal science, according to Kuhn,

a scientific community works on a well-defined textbook.

For example in the case of Newtonian mechanics, as a scientific paradigm,

the main textbook will be Newton's 'Principia'.

And all the scientific activity consists in solving problems,

a specific puzzle arising from this textbook tradition.

So, despite what Popper said, according to Kuhn during periods of normal science

there is no attempt to falsify or refute a scientific theory.

So the accepted scientific paradigm undergoes a period of

crisis only when a sufficiently large number of anomalies accumulates.

During periods of crisis, a new paradigm may come to the fore, and the scientific

community may decide to abandon the old paradigm and shift to the new one.

This is what Kuhn called the paradigm shift.

Kuhn, however, stressed how the paradigm shift, or the process of theory choice

is not dictated by the superiority of the new paradigm over the old one.

On the contrary, Kuhn claimed that the new paradigm should only be

able to have a higher puzzle-solving power than the previous one.

So, the new paradigm should be able to solve the anomalies,

solve the puzzle that the previous paradigm wasn't able to solve.

So, in this way, Kuhn redefined the whole idea of how science progresses,

not in terms of scientific theory being true or more likely to be true, but

in terms of their capacity for solving puzzles and problems.

This shift of focus from Popper Falsificationism to Kuhn puzzle solving has

far reaching implications for the debate on the rationality of theory choice.

Kuhn famously argued that some scientific paradigms are incommensurable.

Incommensurable means they lack a common measure,

common measure to assess and evaluate them,

not to compare them.

Kuhn was absolutely clear that we can compare paradigms.

But it was also clear that we don't have a common measure for judging, assessing or

evaluating whether one paradigm is better or superior than the other one.

Different scientific paradigms use very different theories,

very different concepts,

but also different experimental, technological resources and

system of values.

So that, whenever we have a paradigm shift,

we experience something similar to what psychologists call Gestalt switches.

Like those we're all familiar with as in the case of a famous bistable images,

such as the duck-rabbit.

We will go back to Duhem, the problem of underdetermination of theory by evidence,

Kuhn and the rationality of theory choice, in our session on dark matter and

dark energy,

where we discuss whether current cosmology is undergoing a possible paradigm shift.

We very much look forward to seeing you all in the next class.

Thank you.

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