WHAT IS SCIENCE?
Philosophers of science ask higher-level questions about how science actually works. Philosophers of
biology do this for biology. Philosophers don’t gather data themselves. They help to determine when to
reject a certain theory and take on another. Philosophers use different methods than scientists, as they
partly address questions that cannot be answered by the same methods (e.g., how scientists act vs. how
scientists should act):
Reflecting on implicit assumptions of scientific practice
Uncovering norms and values in science
Questioning the methods of science
Exploring the limits of scientific knowledge and inquiry
Philosophical methods are logical reasoning, thought experiments, conceptual analysis, etc. One of the
most central methods is the use of arguments and counter-arguments. Philosophers investigate topics by
making and responding to arguments. To make an argument is to give a set of reasons (‘premises’) in
support of a conclusion. The function of premises is to support the conclusion. The conclusion should, in
some way or another, follow from the premises without simply restating them. To make a counter-
argument is to show that a conclusion does not follow from certain premises or that the premises are
false.
Science vs. pseudoscience
The distinguishing feature of science lies in the particular methods that scientists use: experimentation,
observation, theory construction. However, this leads to the demarcation problem, which concerns
demarcating ‘proper’ science from look-alikes. Pseudoscience is a non-science posing as science. But, not
everything that classifies as non-science is pseudo-science (e.g. theology, ethics). Defenders of pseudo-
science commonly promote a view that substantially deviates from the established scientific theories
(e.g. fraud, manipulation of data, postulation of new entities and laws). Demarcation is not always easy
as science changes over time and science in itself is heterogeneous. Examples of sciences:
The discovery of the planet Vulcan seems pseudoscience, but Le Verrier had ‘evidence’ that it
really existed. So, it is still classified as science. It provided a solution that could be true, based on
the knowledge they had.
Cryonics is speculation of possible science that is impossible to predict. So, no pseudo-science,
but speculation science. However, it is still considered science, because the actual testability of
an hypothesis doesn’t determine if something is science or pseudoscience.
‘Savior of Mothers’ (a suspected connection between childbed fever and handling corpses) and
theory of evolution are considered science.
Finding an ‘essential’ feature common to all and only those disciplines we consider sciences seems
unlikely. However, there are clear examples of science and clear examples of non-science/pseudo-science
and some central features that might guide their distinction. Scientific endeavors aim to reveal natural
regularities (‘laws’) in order to explain and predict the occurrence of empirical phenomena. This might
help to distinguish science from non-science (e.g., theology, ethics). A scientific theory must be open to
be checked against experience. At least hypothetically, it must be possible to prove a scientific theory to
be false. This might also help us to distinguish science from pseudo-science.
Falsificationism
Popper (1963) tries to identify a single criterion that enables us to distinguish science from pseudo-
science. He is not interested in whether a theory is true or false, or whether it is significant and
meaningful. He is interested in what guarantees the status of a theory as scientific. Popper gives a very
short answer to the question of what makes a theory scientific: falsifiability, refutability, testability.
Popper’s conclusion on falsificationism are:
, 1. It is easy to obtain confirmations, or verifications, for nearly every theory, if we look for
confirmations.
2. Confirmations should count only if they are the result of risky predictions. That is to say, if,
unenlightened by the theory in question, we should have expected an event which was
incompatible with the theory, an event which would have refuted the theory. A risky prediction
is something that can almost only be predicted with your theory and not others. This gives a high
change on being false and is thus a risky prediction. If you don’t believe in this theory, you
wouldn’t make this prediction.
3. Every 'good' scientific theory is a prohibition. It forbids certain things to happen. The more a
theory forbids, the better it is. In evolutionary history, it is prohibited that a specie exists without
having ancestors. This provides opportunities for the theory to be proven wrong. The more
opportunities, the better the theory is.
4. A theory which is not refutable by any conceivable event is nonscientific. Irrefutability is not a
virtue of a theory (as people often think) but a vice. If there is hypothetically no possibility to
show that the theory is wrong, this is seen as nonscientific.
5. Every genuine test of a theory is an attempt to falsify it, or to refute it. Testability is falsifiability,
but there are degrees of testability. Some theories are more testable, more exposed to
refutation, than others. They take, as it were, greater risks.
6. Confirming evidence should not count except when it is the result of a genuine test of the theory
and this means that it can be presented as a serious but unsuccessful attempt to falsify the
theory.
Science motivates a critical attitude understood as the readiness to change one’s
assumptions. To test them, to refute them, to falsify them. In contrast to a dogmatic
attitude related to pseudo-sciences, mainly aiming to confirm and verify one’s
assumptions, by all means necessary.
7. Some genuinely testable theories, when found to be false, are still upheld by their admirers. For
example by introducing ad hoc some auxiliary assumption, or by reinterpreting the theory ad
hoc in such a way that it escapes refutation. Such a procedure is always possible, but it rescues
the theory from refutation only at the price of destroying, or lowering, its scientific status.
An ad hoc explanation is formed only for a particular purpose, to address a specific problem - such as the
problem of immunizing a theory from falsification by a certain anomaly. What makes a hypothesis ad hoc
is not the content of the hypothesis but the motivation of why it is proposed. Popper is suspicious of ad
hoc explanations as they are considered to make a theory less and less falsifiable. Thus, he considers the
introduction of ad hoc explanations an unscientific practice. For example, creationism is considered
pseudo-science, because it is not falsifiable, whereas the evolution theory is. According to the Arkansas
Act 590, schools need to teach both equally. Creationism doesn’t provide a list that can be proven wrong
for them to admit their theory is wrong. They just come with ad-hoc explanations.
However, there are also challenges to falsificationism. Popper‘s criterion might be overly simplistic.
Scientific theories are not rejected whenever they conflict with empirical data. Instead, scientists quite
often stick to their theories and try to save them by means of auxiliary ad-hoc hypotheses.
FORMS OF INFERENCE
Science is supposed to teach us about the world. How can science help us to gain knowledge about the
world? Science relies on inferences. Inferences are different kinds of ways to interpret premises (from
observation to hypothesis). The observations can be the premises and the hypothesis is the conclusion.
There are 3 kinds of inferences: deduction, induction and abduction.
, Deduction
In a deductive inference, the truth of the premises guarantees the truth of the conclusion. If the premises
are true, then the conclusion must also be true. The conclusion is not restating the premises, but making
an inference. If the premises are false, the conclusion might still be true. The premises entail the
conclusion.
No human is ticklish Bachelors are unmarried All Frenchmen like wine
Julie is a human John is a bachelor Pierre is a Frenchmen
Julie is not ticklish John is unmarried Pierre likes wine
Deductive inferences provide proof in a strict sense. When we start with true premises, we know with
certainty that we will end up with a true conclusion. However, some might include false premises. A
distinction is made in the validity and soundness of a deductive inference. In a valid deductive inference,
the truth of the conclusion is guaranteed by the truth of the premises. In a sound deductive inference,
the truth of the conclusion is also guaranteed by the truth of the premises, but in this case, the premises
are actually true.
Deductive inferences are not often used in science, because they are hard to come by. Even if a
deductive inference can be made, it is rather trivial.
Induction
In inductive inferences, the truth of the premises makes the conclusion likely. Even if the premises are
true, the conclusion could still be false. We are rather making an ‘informed guess’. Induction is weaker
than deduction. We cannot be absolutely sure. Induction relies merely on the assumed similarity holding
between members of a certain category or reference class.
Mary lives in Scotland Person A with down-syndrome has 3 copies of
chromosome 21
Almost everyone who lives in Scotland owns a Person B-Z with down-syndrome has 3 copies of
raincoat chromosome 21
Mary owns a raincoat Everyone with down-syndrome has three copies
of chromosome 21
In inductive inferences, we assume the “uniformity of nature”. Based on our past experiences with
singular instances of a reference class, we make conclusions about the entire reference class, including
unobserved instances. We presuppose that all instances of a category are sufficiently similar, including
that the future is sufficiently similar to the past. In science, we often conclude from observed to
unobserved entities (seeing a white swan all swans are white). These conclusions are based on our
past experiences and the assumption of the ‘uniformity of nature’. But we can’t be sure. The truth of the
premises cannot guarantee the truth of the conclusion. This is known as the Problem of Induction.
According to Hume, we cannot prove the truth of the uniformity of nature. However, we do have
empirical prove that the world behaves in an uniform manner. We know from the past that the future
resembles the past. This is circular reasoning, we are presupposing the uniformity of nature.
Abduction
Abductive inferences are inferences to the best explanation.
The cheese in the larder has disappeared, apart Tim and Harry had a fight
from a few crumbs
Scratching noises were heard coming from the Yesterday, Tim and Harry went for a run together
larder last night
The cheese was eten by a mouse Tim and Harry have made up
Abductive inferences look a lot like inductive inferences. And indeed, they are related. Furthermore,
neither of these two forms of inference guarantees its conclusions. But there are some differences:
Abductive inferences often make explicit references to explanations.
Inductive inferences often rely on similar categories or comparison classes, abductive arguments
need not.
Inductive inferences rely on past experiences, abductive arguments need not.