1. Why ask the question “What is Science?”?
The impact and importance of modern science.
In many public debates, some notion of science is presupposed.
Different disciplines have different approaches and standards. Perspectives from “within” can lead to restricted views of science.
Science plays an influential role as an institution in modern society. That role needs justification.

2. The Object of the Question “What is Science?” Science vs. Wissenschaft

3. Possible Answers
List of examples
A description
A definition
sharp vs. vague
by method
Diachronic vs. ahistorical answers

4. Follow-up questions 1st session
Is it possible to answer the question at all?
Re: Justification of the question: Isn‘t there a value to science itself, without referring to its function in modern society?
Who is the answer for? And who is posing the question and when/where?
How to influence science?
Is our method of answering the question also science?

5. Hoyningen-Huene 2013, p. 5

6. What is philosophy of science?
social
Phil. sci. analyzes the
epistemic
epistemic
practices of science
practices of science
technical
Explaining things
Describing things
Predicting things
Formulating theories/models/hypotheses
Justifying/confirming/refuting theories/models/hypotheses
General philosophy of science takes a general perspective on these topics.
The philosophies of the special sciences focus on specific disciplines (physics, biology, chemistry, climate science etc.)

7. Warning
Everything to be discussed is controversial!

8. The one monster called SCIENCE that speaks with a single voice is a paste job constructed by propagandists, reductionists and educators.
Paul Feyerabend,
The Tyranny of Science

9. Philosophy of science is about as useful to scientists as ornithology is to birds.
Attributed to
Richard Feynman

10. Follow-up questions 2nd session
A scientific approach would imply that some philosophers are right while others wrong, is this really true?
Could a possible answer to the general question “What is Science?” be that science is the process of using a systematic and transparent approach in order to produce justifiable knowledge claims?

11. Charles Sanders Peirce (1839-1914)
American logician, mathematician, philosopher
Many contributions to logic, mathematics (e.g. Peirce Operator NAND/NOR, truth tables)
... and philosophy (e.g. pragmatisim, methodology of science)
Historical Context
Early 19th century: Emergence of the historical sciences/natural history (see Bowler & Morus, ch. 5&6).
In the second half of the 19th century: extensive debate among philosophers and methodologists of science about the methodology of the inductive sciences as well as the nature and validity of inductive inferences in general.
See the Mill-Wheewell controversy.
This debate was tightly linked to developments in the sciences at the time.
Peirce‘s Deduction, Induction, and Hypothesis makes an important systematic contribution to this debate.

12. (Peirce: „Hypothesis“)
Types of Inferences
Deduction
All the beans in this bag are white
These beans are from this bag
These beans are white
Properties:
The truth of the premises warrants the truth of the conclusion.
In a deductively valid argument, it is impossible that the premises are true and the conclusion is false.
Logically necessary
Not ampliative (“analytic”)
A deductive argument is called „sound“ if its premises happen to be true.
Induction
These beans are white
These beans are from this bag
All the beans in this bag are white
Properties:
The truth of the premises does not warrant the truth of the conclusion.
It is possible that the premises are true and the conclusion is false.
Not necessary
Ampliative (”synthetic”)
Abduction
(Peirce: „Hypothesis“)
All the beans in this bag are white
These beans are white
These beans are from this bag
Properties:
The truth of the premises does not warrant the truth of the conclusion.
It is possible that the premises are true and the conclusion is false.
Not necessary
Ampliative (”synthetic”)
The conclusion „explains“ the premises.
Inference to the best explanation
C. S. Peirce, Deduction, Induction, Hypothesis (1878)

13. Hume on Causality
„Here is a billiard-ball lying on the table, and another ball moving towards it with rapidity. They strike; and the ball, which was formerly at rest, now acquires a motion. This is as perfect an instance of the relation of cause and effect as any which we know, either by sensation or by reflection. Let us therefore examine it. ’Tis evident, that the two balls touched one another before the motion was communicated, and that there was no interval betwixt the shock and the motion. Contiguity in time and place is therefore a requisite circumstance to the operation of all causes. ’Tis evident likewise, that the motion, which was the cause, is prior to the motion, which was the effect. Priority in time, is therefore another requisite circumstance in every cause. But this is not all. Let us try any other balls of the same kind in a like situation, and we shall always find, that the impulse of the one produces motion in the other. Here therefore is a third circumstance, viz., that is a constant conjunction betwixt the cause and effect. Every object like the cause, produces always some object like the effect. Beyond these three circumstances of contiguity, priority, and constant conjunction, I can discover nothing in this cause. The first ball is in motion; touches the second; immediately the second is in motion: and when I try the experiment with the same or like balls, in the same or like circumstances, I find that upon the motion and touch of the one ball, motion always follows in the other. In whatever shape I turn this matter, and however I examine it, I can find nothing farther.“
(An Enquiry Concerning Human Understanding, Abstract of a Treatise of Human Nature)

14. Follow-up questions 3nd session
As we heard right at the end, problems are coming: We have to discuss and oppose different hypotheses against each other in science. So based on what methods can we distinguish between these hypotheses?
Might inductive reasoning be becoming more important nowadays due to large amounts of available data (including new forms of data from e.g. social media or sensors) that can be analyzed by scientists using computer algorithms in an explorative way?
Shouldn’t inductive inference lead to hypotheses? Or in other words: If we state that something is true in all cases, shouldn’t we try to find a reason for it?

15. David Hume and the Problem of Induction
Reasoning that goes beyond past and present is based on cause and effect
The relation of causality:
1) constant conjunction
2) contiguity
3) priority in time (of the cause)
4) NO necessary connection!!!!
David Hume
1711–1776
The Problem of Induction:
How can inferences from the past/present to the future (or from observed instances to unobserved instances) be justified?

16. Hume‘s Skeptical Solution
„All inferences from experience, therefore, are effects of custom, not of reasoning. Custom, then, is the great guide of human life. It is that principle alone which renders our experience useful to us, and makes us expect, for the future, a similar train of events with those which have appeared in the past. Without the influence of custom, we should be entirely ignorant of every matter of fact beyond what is immediately present to the memory and senses.“
(An Enquiry Concerning Human Understanding, V.1)

17. The starting point of modern philosophy of science: The Vienna Cirlce
Moritz Schlick
Rudolf Carnap
Victor Kraft
Hans Hahn
Otto Neurath
Herbert Feigl
Friedrich Waismann
Philipp Frank

18. The scientific world view of the Vienna Circle: Two main features
Positivism & Empiricism: „[T]here is knowledge only from experience, which rests on what is immediately given. This sets the limits for the content of legitimate science.“
Logische Analyse & Reduktionismus: „The aim of scientific effort is to reach the goal, unified science, by applying logical analysis to the empirical material. Since the meaning of every statement of science must be statable by reduction to a statement about the given, likewise the meaning of any concept, whatever branch of science it may belong to, must be statable by step-wise reduction to other concepts, down to the concepts of the lowest level which refer directly to the given.“

19. The scientific world view: Further programmatic features
unified science
anti-metaphysics
rejection of synthetic statements a priori
liberalism & socialism

20. The scientific world view: The verificationist criterion of meaning
The criterion which we use to test the genuineness of apparent statements of fact is the criterion of verifiability. We say that a sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express — that is, if he knows what observations would lead him, under certain conditions, to accept the proposition as being true, or reject it as being false. Ayer, Language, Truth, Logic (1936).
„ Einen Satz verstehen, heißt, wissen was der Fall ist, wenn er wahr ist.
(Man kann ihn also verstehen, ohne zu wissen, ob er wahr ist.) [...]“
Wittgenstein, Tractatus logico-philosophicus, 1922.
„Es ist der erste Schritt jeglichen Philosophierens und das Fundament jeder Reflexion, einzusehen, daß es schlechterdings unmöglich ist, den Sinn irgendeiner Behauptung anders anzugeben als dadurch, daß man den Tatbestand beschreibt, der vorliegen muß, wenn die Behauptung wahr sein soll.” Schlick, Positivismus und Realismus, 1932