Philosophy of Science: Lecture Notes
LECTURE 1 - INTRODUCTION & ANCIENT PHILOSOPHERS
What are we going to do?
The question of the course is “What is science?” and there are many answers possible.
We are going to look at these answers and then apply them to psychology but also
physics, astronomy and astrology to see whether the different answers actually work.
Having the knowledge of psychology, we can apply an answer to the question “What is
science?” and see whether psychology is in fact, a science or not. The course is mainly
structured in a historical fashion; we start with epistemology. Thinking about science
starts with thinking about knowledge and the old greek word for knowledge is
“episteme”. Thinking about knowledge then leads to thinking about science. The
reason why we take this historical approach is because otherwise we would not know
where the answers to all these questions came from. Thus, we start by looking at
epistemology in ancient Greece and how the old greek philosophers thought about
knowledge. So, in short:
1. We are going to think about what science is.
2. We are going to think about the question whether psychology is a science (so,
it is a reflection on what you have been studying).
Used abbreviations throughout the course: Exploring Humans (EH) and Hans
Dooremalen (HD).
1. WHAT IS PHILOSOPHY OF SCIENCE?
Philosophy is critically thinking about something. In this case
it's science so it's thinking critically about science → critical reflection on what science is
and how science generates knowledge.
➢ Take for instance two claims made by Stephen Hawking; he claims that he is a
scientist and has knowledge about black holes. Black holes are things in the
universe where gravity is so strong that light doesn't even bounce off of them. We
cannot see black holes.
➢ In the Netherlands there is an allegedly paranormal medium, called Yokodan,
who claims to determine invisible illness some people have (ghosts tell her?). If
you claim a scientific status for what she does, then you would be considered a
pseudo-scientist.
, ➢ Hence the question; What's the difference? Both things are something we
cannot directly observe, but Stephen Hawking is regarded as a scientist, he is
the prototype of a real scientist. Although the medium talks about things we
cannot observe either, we do not believe in what she does/talks about and
consider her a pseudoscientist.
So in short:
Philosophy of science → this philosophical (critical) reflection on what science is,
does, and how it generates knowledge.
➢ For example: Why do Stephen Hawking's claims about black holes fall within the
realm of science and Joke Damman’s claims about white ghosts do not?
What is science?
When we use word science we usually use it in the right manner. It is not that we make
a mistake if someone says “I am eating a sandwich, therefore, I am a scientist” →
Nobody would use the words “scientific method” for such a statement. It is fairly easy
to see how people use the word science but it becomes more problematic if we have to
reflect; think more critically or in more detail about it, so that we can answer the
question; “What is it that makes something science and something else not science?
What's the difference, so what exactly is science?”
We will get back to this question and discuss it in more detail. But, shortly:
A. We use the word ‘science’ often and use it in the right manner.
B. But what are the characteristics of science?
We have an idea of what science is, but no clear answer, i.e. we use the word correctly
and can tell when people do not use it properly, but it is not easy to answer the question
what exactly is science?
2. WHAT IS PHILOSOPHY OF SCIENCE FOR PSYCHOLOGISTS?
Psychology is a science.
→These days psychology does have the status of being a science. But the question is;
“Is that true? Is psychology rightfully classified as a science?”
Knowledge, skills and character
As an academic you should be able to explain why psychology is classified as a
science.
➢ This requires knowledge: You need to know the different answers that have
been given in the history of thinking about science to the question what is
science?
, ○ As an academic you should be able to explain why psychology is
classified as a science; so you need to have knowledge. If someone asks
you whether psychology is a science or not, you should be able to know
the answer to that question. The answer to that question can differ as
people might have different arguments for the different properties they
ascribe to science. By looking at the ancient greek philosophers we will
see where all these answers, to what is science and what is not, came
from.
➢ Besides having the knowledge, you need to have the skills to reflect on
questions like:
○ Is psychology a science? Is it justified to call psychology a science?
○ Is it justified that science has the monopoly on acquiring knowledge?
○ To reflect, you also need to have the skills. You should be able to provide
an argument for your view so is it justified that science has the
○ monopoly on acquiring knowledge for instance. That is a really important
question and you need to have the knowledge to answer that but also the
skills to be able to make a proper argument; so is it justified.
○ There is a replication crisis in psychology: Is psychology a science? In
science usually only positive results are being published.
➢ When is something science? Philosophy is critical reflection, and for that you
need knowledge & skills.
➢ But that is not everything as knowledge and skills also serve another goal:
building of character.
○ Other than knowledge and skills, we want you to have a built character
and that is related to the idea of having knowledge and skills. For
example, good psychologists should be able to use therapy but also
understand when they should use a certain therapy etc. So, a built
character is highly important as well, only the knowledge and the skills are
not enough for you to be a good scientist.
Better psychologists, better scientists and better citizens
➢ By thinking critically about science, and about the scientific status of psychology,
we hope that you gain insight in psychology as a science, and thus become
better psychologists.
➢ No university wants to have another Stapel. We will see that thinking about the
scientific status of your own discipline is not that easy.
We do not want to educate students in order for them to just make a lot of money:
Tilburg University → Understanding society → Advancing society!!!!
,3. EPISTEMOLOGY
Epistemology = theory of knowledge.
Philosophy of science began with epistemology. Epistemology asks three questions:
1. What is (certain) knowledge?
2. How can we justify that knowledge?
3. What is the source of knowledge?
Traditionally there are two views:
1. Rationalism: real knowledge is derived from the ratio, reason.
2. Empiricism: real knowledge comes from sensory experience.
Philosophy of science started with epistemology, the theory of knowledge. Epistem
is the old greek word for knowledge, so it's a theory of knowledge we started with. The
old greek philosophers were already asking questions about knowledge but not about
science, you could say there was no science back then → No science? No questions
about it. So what kind of questions were they asking? For instance, what is certain
knowledge or how can we justify knowledge. Traditionally there are two views that say
there is a source of knowledge so: Rationalism says that knowledge comes from using
your ratio, your reason properly. On the other hand, Empiricism says that real
knowledge comes from using your sensory experience that's the source of knowledge.
So that's that's more common sense in comparison to rationalism. Rationalism is more
counterintuitive but still it's a positive answer to the question “Is knowledge possible? If
yes, where does it come from?”.
Is it possible to have real knowledge? What are we certain of?
3.1 Scepticism
People that claim we cannot cannot have any knowledge at all are skeptics and they
defend skepticism.
➢ Socrates in the market square, asks difficult questions.
➢ Scepticism: ‘Perhaps the conclusion must even be that we do not know
anything at all, and never will.’ (Dooremalen, De Regt, & Schouten, 2017, p. 12)
➢ Socrates is convinced.
➢ Is there anything we can be certain of?
Socrates was a sceptic and he was the teacher of Plato. Plato was the teacher of
Aristotle. Socrates used to ask a lot of questions to young people who wanted to
debate with him on various topics. He would ask them whether they are absolutely sure
of their opinions. He used the so-called socratic method. Socrates claimed that it's
,always possible to ask questions about whether one really knows something and then if
the answer is “No, I don't”, it means that you can't have knowledge and that's
skepticism. The conclusion must even be that we do not know anything at all and
never will → that's what a skeptic would say.
3.2 Rationalism
Rationalists would argue that we can be sure about many things. Rationalism in general claims
real knowledge stems from our reason, our ratio hence rationalism. The idea has an
associated claim and it is the claim that innate knowledge is possible and that's called
nativism and innate knowledge; inborn knowledge and that's knowledge you already
possess when you're born as a little baby. Different rationalists have different interpretations of
rationalism. Plato is the most radical rationalist but there is also Rene Descartes who is also
a rationalist but he's much more sophisticated, thus not as radical.
● If a question on the exam asks to explain rationalism please do not give the theory of
plato as if that is the general view of rationalists; his view is a very specific view on
rationalism. So keep that in mind the general claim is just where knowledge comes from
→ from using your reason properly and the associated claim is that there is innate
knowledge.
A. General claim: Real knowledge stems from our reason (ratio).
B. Associated claim: There is innate knowledge (=nativism).
Rationalist #1: PLATO
Plato claims that the source of knowledge is a ratio and that to learn something is
actually not learning but is to remember and he calls that amnesis. The the theory of
Plato is really odd because he says there is no new knowledge and that's strange
because if you didn't do any philosophy course prior to this one and never read about
Plato, then you didn't know that Plato claimed that there is no new knowledge → so
that's new knowledge to you. Thus, it is strange that Plato claimed there is no new
knowledge. There are several things that Plato responds to and one of them is belief in
reincarnation (but not in the way of paranormal stuff). How Plato believed in
reincarnation is that he believed a soul is in your body and can get out of your body and
go to a different one.
The source of knowledge is our reason.
➢ Plato: To learn is to remember ( = anamnèsis)
➢ In other words: There is no new knowledge – you do not really learn anything
(but did you know this?)
➢ Question: Why did he claim this?
➢ Plato believed in reincarnation.
,Forgotten everything
Plato believed that before you were born, you had all real knowledge (& you lost that
knowledge when you were born).
➢ Plato believed that your soul already possessed all the knowledge, all the things
that can be known prior to being born. When you were born that was kind of a
traumatic experience which made you forget everything you already know;
meaning, after being born, you don't have immediate access to your knowledge
anymore but you can access it by using your reason properly. So basically your
soul has all the knowledge it knows everything there is to know. Your soul is born
into your body and then you forget it and then you need to use your ratio to recall
this knowledge again. Therefore if you remember it, it's not new, it's all old
knowledge.
Episteme vs. Doxa
Plato makes a distinction between episteme that is the old greek word for knowledge
and doxa and that's the old greek word for opinion. You can have an opinion about how
things are but it might be false. On the other hand, if you have knowledge about how
things are that can be false unless it's real knowledge, then it has to be true.
Plato wants to make this distinction between real knowledge and mere opinion
knowledge. Plato says you can have opinions about how things are and you can have
knowledge about how things are and ARE here is the key so we're talking about being
we're talking about “to be” and about IS and ARE.
I. Episteme: Knowledge of how the things are.
II. Doxa: Opinion about how the things are.
Plato: k nowledge = justified & true belief.
➢ One thing important to mention here when we're talking about episteme is that
knowledge is defined by Plato as a justified and true belief. So you have a belief,
a mental state about the world and it's true → that means it corresponds to the
facts and the way your mental state represents it. So it's a true belief and also it's
a justified and true belief. Justified means that you can explain how you know
that it's true, you also have to have a proper justification. This is a problem a
sceptic would say you will never be able to provide a proper justification for any
belief. So in terms of Plato that means that you have a mere dark side and you
have a mere opinion about the world. Plato doesn't want to be a skeptic and thus
he makes this distinction between episteme and doxa.
Plato responds to Heraclites
If you look into the world if you look at the world then you have to notice that everything
is in constant flux; everything is constantly changing so panta rhei means that
,everything is in a constant flux → the world we perceive with our senses and you see
things change. You see the weather changing, you look at the river and you see that the
water is floating through the river and so you see the river change. There is a saying
that one cannot step into the same river twice. B ut because you step into a river and
you step out and when you step into the river again it's a different water; it has changed
and also you have changed, for example what you consumed has been digested. So if
you say you cannot step into the same river twice that's not only because the river
changes but also because you change.
So Plato says if you have knowledge about the world we perceive with our senses, you
don't have real knowledge because you can only have knowledge about how the things
are and that means if we're talking about the world we perceive with our senses we
can only acquire a dark side not episteme. We can only have opinions and those are
false opinions. The river is something that's changing so you cannot have knowledge
about how the river is; that's impossible so that would amount to skepticism and
Plato doesn't like skepticism; he is a student of Socrates but he doesn't agree with him.
➢ Panta rhei;
➢ If in our world (= the world we perceive with our senses) everything changes
constantly, then nothing is…
➢ And that means we can only acquire doxa, not epistème…(and that would
amount to skepticism).
But Plato did not want skepticism.
To understand it, we need to go back to Socrates. Socrates doubted the existence of
the greek gods and hence he got convicted. If you do believe in the greek gods then
you have all kinds of explanations of things in the world; why is there thunder and
lightning why does it rain? In the end you can always refer back to a theological
explanation and it's explained by the actions of the gods. If you reject that mythological
view of the world and then conclude we do not know anything well you could be
satisfied with that and say that we don't know anything so basically what Socrates did.
Imagine you are Plato and you say that Socrates is right and you do not believe in the
existence of the greek gods but also don't think we cannot know anything. Plato arrives
at the conclusion that we cannot have knowledge about this world but if knowledge is
possible; it has to be knowledge of a different world.
Plato’s allegory of the cave
Plato says there's a different world from the world we see and perceive with our
senses. There has to be a world where the things are not changing, where they actually
are and that's the world of forms and ideas so there is a world and that contains all the
ideas, all the forms and these ideas do not change. Plato illustrates this with the
,allegory of the cave; imagine that there are people in a cave, they are chained to a
wall and in front of them there's another wall and it's dark. They only see what's in front
of them, they can't look up or behind them and high above them. On a road behind the
wall behind them where they are chained to the wall, there's a road and so are people
holding chairs just high enough that the fire (that's even further away) falling on these
chairs caused a shadow on the wall all in front of the prisoners and it cost not the
shadow of the people but it caused the shadow only of the tables and the chairs and the
stuff they were holding. The prisoners only perceive and observe these shadows of
chairs and tables believe that the shadows are the real chairs etc.
→We are in a similar situation; our souls are imprisoned in our bodies and we see
what we believe is a real table but the real table isa concept/an idea in the world of
forms in the world of ideas. So we're basically in this same situation in which we believe
that what we perceive is the real world while there actually is another real world “the
world of ideas”. Furthermore, what is interesting is that Plato described this as a
universal concept; chair is a universal concept that applies to all chairs. The idea that
table is a universal concept that applies to all tables. In our world where everything
constantly is changing and we can remember those ideas that iss, at least what Plato
says
I. Ideas/Forms exist apart from us in a World of Ideas/Form World;
II. The soul is akin to those ideas: Acquiring knowledge is to remember these Ideas
– anamnèsis
MENO
Plato gives us an example on how this works and he does this in his book “the Meno”
and that's a dialogue. So Plato wrote a dialogue in which Socrates is the main
character, the protagonist of the play. In this case there is also a man called Meno and
one of his slaves. So Meno is someone who owns land and slaves and he talks to
Socrates. Socrates explains his theory of advances of learning being to Meno (Socrates
here voices the ideas of plato so it's Plato). So in Plato’s dialogue, Socrates is the one
explaining Plato's views; what happens here is that Socrates says to Meno that if you
use your reason properly you can remember the ideas. Meno then says okay; so they're
sitting outside, underneath a tree and there are slaves working in the field, so Meno
says “One of my slaves also would be able to do that” and Socrates replies “Yes, just
call one and I'll show you”. Meno calls one of his slaves and Socrates then draws a
square in the sand. Let's look at his square ABCD → he asks the slave “Do you know
what you have to do to double the surface of this square?” and the slave says “Well yes,
have to double the line AB, hence extend it and also do that with AD; extend it as well
by a similar line of a similar length and then make a square again and then you have
doubled the surface of the square”. Socrates makes this square so then you
,get the square AEGI and then it turns out of course if you also draw on the other two
lines it is pretty obvious that this is four times the original surface or four times the
original size of the square. So then the slave says “Socrates you're right this is
four times the original surface” and then Socrates does this; draws the diagonals of
these squares in such a way that you also have a square that is BFHD and also is a
square and that consists of four triangles each of which is half the size of the original
square; so four times half the size of the original square is actually two times the surface
of the original square - that's double the square you need to draw in the sand to get a
square that has double the size of the original square. The slave then says something
“You're right, now I remember this idea of how to double the size of the square”. Meno
then is convinced that Socrates is right with this theory of anamnesis but this is
unacceptable.
This is obviously unacceptable: Socrates puts the slave of Meno words in the mouth.
This kind of rationalism is very extreme. Descartes had a weaker version (which we’ll
see in lecture 2).
➢ This is unacceptable; Socrates is leading the witness -we would say- it's learning
by telling someone something new. You can then call it remembering but that's of
course just a trick that Plato used to convince his reader. The slave learned
something new and therefore we cannot accept this as evidence of this theory of
anonymous.
3.3 Empiricism
The second view in epistemology claims that we can have knowledge so it's a view that
argues against skepticism. This view is called empiricism; the general claim of
empiricism is that knowledge comes from the experiences we have when we observe
the world. When you observe the world you get all kinds of input in your system → you
use your senses then you experience all kinds of things and that is the source of
knowledge.
, General claim: Empiricists believe that the source of knowledge is the experience
gained through sensory perception. This is a common sense view: If you want to know
how something is, you have to look (or listen...).
The term “empiricism”
The central claim thus is that you gain knowledge from the experiences you have. In
Greek: empeira and Latin: experienta.
➢ Associated claim: If all knowledge comes from experience via perception, there
is no innate knowledge.
The term empiricism refers to our experiences; you gain knowledge from the experience
you have and you can't be wrong about your experiences. The question then is
“Do your experiences correspond through something in the world? There is the
associated claim that implies no innate knowledge; if all knowledge
stems from using your senses then of course there is no innate knowledge.
Empiricist =/= Empirical
Empiricist and empirical are two different words. They might have the same origin but
there is a difference in meaning. Empiricist refers to empiricism, the view we are now
discussing in this lecture; so the view that knowledge stems from sensory experience
and then empiricist is the opposition of rationalists. However, you also have the word
empirical and that refers to the scientific method where you use observation and
experience to gain knowledge about the world; then you have empirical evidence. For
instance you can use the word empirical to say something about evidence and then this
evidence gained through observation and experiments is the opposite of purely
hypothetical. You can think of something without having evidence and then you don't
say that that's an empirical claim you make; the empirical claim can be made only after
you have evidence stemming from observations etc.
There is a difference between empiricist and empirical:
➢ ‘Empiricist’ refers to empiricism, the view that knowledge stems from sensory
perception. Empiricist is the opposite of rationalist.
➢ ‘Empirical’ refers to the scientific method, which uses observational
experimental data to infer conclusions about the world. Empirical evidence is
evidence that is gained through observations or experiments. Empirical is the
opposite of purely hypothetical.
