Philosophy of Science

1. Philosophy of Science Faghrie Mitchell BCB 703: Scientific Methodology

2. can can can MYTHOLOGY RELIGION DOGMA MYTHOLOGY RELIGION DOGMA SCIENCE PHILOSOPHY SCIENCE PHILOSOPHY SCIENCE can Summary: Ancient Egyptians Summary of section on ancient Egyptians • The two points made in the preceding slides, effectively summarise this section • I have covered the first path so far (striked out). I will combine the second and third paths, and discuss them as if they are one Ref:

3. What is Philosophy? What is Philosophy? • How do we maximize right and minimize wrong? • Or rather, How do we maximize SCIENCE and minimize NONSCIENCE? • Just by asking these questions we are asking philosophical questions. We are also answering what philosophy is. • “So what is philosophy anyway? Philosophy is not there to solve practical problems, problems of society or individual. Rather philosophy tests our most fundamental beliefs, values and convictions that we have, and to test them for the purpose of getting them right. This testing is in the form of asking critical questions, of debating, which is the central aspect of the philosophy. Philosophy is the love of wisdom. The love of getting to the right answer using debate.”(Daniel Robinson, Georgetown University). RefRobinson:

4. What is Philosophy of Science? What is Philosophy of Science? • Understanding philosophy can be simplified by asking two simple questions, namely:1. What is good, what is bad?2. What is right, what is wrong? • The first question relates to human behaviour, specifically, for example, ideas on virtue, morals and ethics.BROAD STATEMENT: Scientists are less interested in this. • The second question relates specifically to ideas on logic and reason, and perception and reality.BROAD STATEMENT: Scientists are more interested in this. • So even though we can say that “Philosophy is not there to solve practical problems, …”, it does not mean that we cannot use philosophical thought to help us solve scientific or practical problems. RefRobinson:

5. The Age of Mythology: The Iliad The Age of Mythology • The role of the gods in the thinking of the ancient Greeks is illustrated in the epic by Homer (c. 7th century BC), called the Iliad • The Iliad is a story which is believed to combine myth (fiction) and ancient Greek history, and is supposed to have happened in the 12th century (The films Helen of Troy and Troy is based on this story) Wikipedia: Homer • The Iliad starts off with the Greek gods Zeus and Poseidon who both desire the sea-nymph, Thetis • They become afraid of pursuing Thetis when it is prophesized that any future son of Thetis wil be greater than his father; so they back off

6. The Age of Mythology: The Iliad The Age of Mythology • They allow Thetis to marry the mortal king, Peleus • At the wedding, you have gods, goddesses, demi-gods and mortals in attendance • A dispute arise as to who is the most beautiful goddess. The gods decide that the young Trojan prince, Paris, must decide • He opts for the goddess, Aphrodite, because she promises him the most beautiful woman in the world, which is Helen Amazon.com RefRobinson:

7. The Age of Mythology: The Iliad The Age of Mythology • Some time later, Paris meets Helen, but unfortunately finds her to be married to Melenaus, a Spartan prince • Helen had many suitors before marriage, each of which who made a pledge to her father to protect Helen and her future husband • So with Helen’s abduction, they set off to Troy Amazon.com RefRobinson:

8. The Rise of Greek Philosophy The Rise of Greek Philosophy • The Iliad clearly illustrates the fickle, emotional, and unpredictable nature of the gods • It also illustrate that the gods interfere with mortals’ lives, but they remain mainly interested in their own needs • The ancient Greeks felt; there was a distance between Olympia (Heaven) and Athenia (Earth) Wikipedia: 12 Gods of Olympus • However, this does not necessarily mean that they started to discard their religion, Olympianism It means that they had to deal with this dualism, each in their own way for example Plato stated: The Earth is imperfect and changeable, the heavens were perfect and immutable

9. The Rise of Greek Philosophy • Prior to the establishment of the first Greek school of thought by Thales of Miletus (c. 624-546BC), the Greeks looked only towards Olympia (heaven) and the gods for explanations relating to their world • Thales theorem: An inscribed angle in an semicircle is a right angle • Also predicted an eclipse would happen in 585BC which actually occurred Wikipedia: Thalus of Miletus Wolfram

10. The Rise of Greek Philosophy The Rise of Greek Philosophy • The Greek philosophers, Plato (427-347BC) and Aristotle (384-322BC), were the first Greek philosophers to adequately deal with questions about their world, their beliefs and their reality – to confront dualism Wikipedia: Plato Wikipedia: Aristotle

11. The Rise of Greek Philosophy: Raphael The Rise of Philosophy Wikipedia: Raphael’s School of Athens; www.hull.ac.uk

12. The Rise of Greek Philosophy: Raphael The Rise of Philosophy • Plato (on the left) pointing upwards: he is interested in the forms, universals, generals Wikipedia: Raphael; www.hull.ac.uk • Aristotle (on the right): he is interested in particulars, specifics Wikipedia: Raphael RefRobinson:

13. Plato (top-down) The Rise of Philosophy: PLATO • Knowledge is that which is true and that which is believed • 1. Something can be true, but is not believed e.g. some truth about our universe which has not been discovered yet2. Something can be believed, but is not true e.g. urban legends, myths, conspiracy theories Wikipedia Plato has a top-down perspective on knowledge, he favours deductive reasoning Ref:fWikipedia

14. Aristotle (bottom-up) The Rise of Philosophy: ARISTOTLE • Aristotle (384-322BC) differed from Plato in that he had favoured a bottom-up approach, and preferred empiricism over deduction • Aristotle more interested in specifics, so he writes the Physics, and then the Metaphysics and later on Historia Animalium • The Historia Animalium was written rather hastily, but contains lenghthy descriptions of countless species of fish, shellfish, and other, animals and their anatomies. www.natuurinformatie.nl RefRobinson:

15. Aristotle (bottom-up) The Rise of Philosophy: ARISTOTLE • The Physics is collection of lessons on theoretical, methodological, philosophical concerns, rather than physical theories or contents of particular investigations. • It sets the bases for scientists to study the world subject to change, and change, or movement, or motion (kinesis) is one of the chief topics of the work. • The Metaphysics is so named because it came after the Physics. It is divided into three parts (1) ontology, (2) theology and (3) universal science. • Ontology is the study of existence; it has been traditionally defined as 'the science of being'. Theology refers to the study of God (or the gods). Universal science is supposed to be the study of so-called first principles, which underlie all other inquiries. RefRobinson:

16. Plato and Aristotle: Two perspectives Plato and Aristotle: Two Perspectives RefRobinson:

17. can can can can MYTHOLOGY RELIGION DOGMA MYTHOLOGY RELIGION DOGMA SCIENCE PHILOSOPHY NONSCIENCE PHILOSOPHY Conclusion: Ancient Greek Philosophy Conclusion: Ancient Greek Philosophy • With Plato and Aristotle, the foundations for deductive and inductive reasoning was put in place, methods of thinking which could maximise science and minimise nonscience • However, this was just a start on an otherwise long road Ref:

18. The Rise of the Roman Empire The Rise of the Roman Empire • The Roman Empire started to emerge in 282BC, after the Etruscans were defeated at the Battle of Populonia, and the defeat of the Greek colony at Tarentum • Rome established colonies in strategic areas, which led to the demise of the Macedonian and Seleucid Empires (c 2nd century BC) • Rome was the superpower, they controlled the Mediterranean Sea wps.ablongman.com Ref:

19. The Rise of the Roman Empire The Rise of the Roman Empire • Greek culture survived, because Rome took it as its own • However, in general, the Romans did not have the same penchant for the dialectic tradition (debate) and philosophy lost its appeal • Rome was more interested in conquest wps.ablongman.com Ref:

20. The Rise of the Roman Empire The Rise of the Roman Empire wps.ablongman.com c. 49-45BCExpansion under Julius Caesar 14-117 CEHeight of Roman Power 284-305 CEThe Empire under pressure Pull back from Britain, Dacia and Mesopotamia

21. The Decline of the Roman Empire The Decline of the Roman Empire wps.ablongman.com c. 400-526 CEBarbarian migrations and invasions 527-565 CEByzantium Empire under Justinian c. 632-750 CERise of Islam

22. The Byzantine and Islamic Empires The Byzantine and Islamic Empires • 9th and 10th centuries • Islam starts to occupy parts of the Byzantine Empire • War between the two blocs, but also dialogue (debate) • Start to see emergence of Islamic and Jewish scholars and philosophers who translates Greek texts into Arabic and Latin • E.g. Al-Farabi comments on Plato’s Republic wps.ablongman.com wps.ablongman.com

23. The Preservation of Scholarship Preservation of Scholarship • Al-Farabi (870-950) comments that justice and rational thought will not come when kings are philosophers and philosophers are kings, but rather it will come when the philosopher is a prophet and a prophet is a philosopher • Many scholars and philosophers produced, e.g. al-Kindi (801–873), Al-Farabi (870-950), Avicenna (980-1037), Al-Ghazali (1058-1111), Averoes (1126-1198). Wikipedia: Al-Farabi Wikipedia: Avicenna

24. The Preservation of Scholarship Preservation of Scholarship • Islam encourages scholarship, as it distinguishes between knowledge, that is (1) ijtihad (debatable) and (2) dogma (non-debatable) • Avicenna (980-1037)“The Father of Modern Medicine” • Ibn-Khaldun (1332-1406) “The Father of Social Sciences” Wikipedia: Averoes www.multimediaquran.com

25. The Fall of the Byzantine Empire The Fall of the Byzantine Empire • 1453Siege mentality • Steady outflow of Byzantine-Greek scholars heading west • Increases scholarship in the West Osprey • Scholarship stopped in476 AD because1. disintegration ofpolitical structures 2. attack and invasions3. loss control of the Mediterranean and trade routes4. emergence of the Church

26. The Scientific Revolution The Scientific Revolution • 12th and 13th centuries • The Renaissance • 1543Scientific Revolution • Publication of Archimedes (287-212 BC) • Copernicus (1473-1543)A heliocentric system • Vesalius (1514-1564)Published work on dissections replaces Galen (129-200AD) Wikipedia Wikipedia: Vesalius Wikipedia: Copernicus

27. The Scientific Revolution The Scientific Revolution • 1543Emergence of Philosophy • Father of Philosophy Rene Descartes (1596-1626)I think, therefore I am • Emergence of Sir Francis Bacon (1561-1626) • Galileo Galilei (1564-1642) • Johannes Kepler (1571-1630) Bacon Descartes Galileo Kepler

28. Descartes vs Bacon Descartes (Platonic) vs Bacon (Aristotelian)

29. Induction: Sir Frances Bacon Sir Francis Bacon: Induction • What is induction?Inductive reasoning starts with an observation. Repeated observation leads one to conclude that: All observed swans are white (specific statement) Therefore all swans are white (general statement) Bacon Observation(s) Wikipedia 1 2 3

30. Problems with Induction Problems with Induction • There are weaknesses to the inductive method of reasoning, for example looking at our argument:All observed swans are white (specific statement) Therefore all swans are white (general statement) • What would happen if we stayed in Europe and only saw, white swans during our lifetime?CONCLUSION: All swans are white • What would happen if we went to Australia and see a black swan? CONCLUSION: We were wrong, our reasoning is not sound Wikipedia: Mute Swan(Cygnus olor) Wikipedia: The Black Swan(Cygnus atratus)

31. Problems with Induction Problems with Induction • Induction can be fatal • For example: The turkey has seen may days come and go; say from 01 January to 24 December 01 January-24 December 25 December www.kidzone.ws www.kidzone.ws

32. David Hume: Problems with Induction Problems with Induction: David Hume • The example of the swans and the turkey are both hasty generalisations, which assumes all swans are white, and turkeys can expect a long life • David Hume (1711-1776), Scottish philosopher, pointed out this weakness of induction Wikipedia • Hume was however, in agreement with Bacon that knowledge must be gained empirically through observation, experience and experimentation • Despite Hume’s objection and the problems with induction, we see three centuries of induction, a massive gathering of scientific knowledge using induction

33. Empiricism vs Dogma Empiricism vs Dogma (Induction vs Deduction) • Sir Francis Bacon emphasised that knowledge could only be gained by experiencing the world i.e. make observations, collect data, conduct experiments (empiricism) • The inductive method of inquiry was in opposition to the dogmatic teachings of the Church, which made biased, subjective assumptions • The Church is dogmatic because it assumes that religious knowledge is true and can be used to derive scientific knowledge or truths; the Church uses deductive reasoning • An example of this clash can be seen with the response of the Church to Galileo, after he supported Copernicus’ idea on a heliocentric system (the Earth is the centre and the other heavenly bodies revolve around it) Bacon Wikipedia: Torquemada

34. Empiricism vs Rationalism Empiricism vs Rationalism (Induction vs Deduction) • Bacon and Hume was also in opposition to the Continental Rationalists, for example Rene Descartes (1596-1626) • Descartes was a mathematician and he followed the same method used by the ancient Greek mathematicians, namely, start with a set of ideas (theorems, axioms) and derive a new theorem from that body of existing knowledge • The continental rationalists, like Descartes, Leibniz and Spinoza, drew a distinction between knowledge of eternal truth, for example, mathematics, and knowledge which had to be gained through experience (experimentation), for example, biology Bacon Descartes

35. Empiricism vs Rationalism Empiricism vs Rationalism (Induction vs Deduction) • New mathematical knowledge can be gained by from existing knowledge using logic and reason • Arrow 1: Use existing mathematical truths (axioms) to derive a preposition); Arrows 2: Prepositions are true if they do not contradict existing knowledge; Arrow 3: New Knowledge (axiom) Observation(s) • Weakness of rationalism: Only certain knowledge can be derived from logic and reason • E.g. if you want to now the distance from A to B you have to measure it, not so much reason about it Wikipedia 2 1 3

36. Hypothetico-deductive Method Hypothetico-deductive Method • The natural and the physical sciences lends itself better to empiricism (induction), and less so to rationalism (deduction, the use of logic and reason alone) • Deduction and induction often work together in the natural and physical science • Sir Karl Popper developed the hypothetico-deductive method to reconcile inductive reasoning with deductive reasoning • The hypothetico-deductive method counters the natural tendency of the mind to want to verify Wikipedia: Popper

37. Hypothetico-deductive Method Hypothetico-deductive Method • Induction ensures that there is an adequate number of unbiased observations (accumulated knowledge) • Induction can be fatal too • Deduction aims to counter the verification of inductionIt asks logical questions knowledge (obtained via induction) • I will show this by using the example of Global Warming and Global Dimming www.kidzone.ws www.kidzone.ws

38. Hypothetico-deductive Method Formulate theory Decide relevant kind of information Decide relevant kind of information needed to test theory Start Again Collect information by observation or experiment Collect information by observation or experiment Store information Analyse information Develop generalisation Consider result Formulate theory Theory provisionally corroborated Falsification Seek verification of theory Theory rejected State law or truth Expose to more stringent tests Eventual falsification New theory required incorporating good points of original theory and new information Tests etc.

39. Example: Global Warming GLOBAL WARMING? 1. Formulate theory Glacier retreat, snow cover, rising sea levels, weather changes 2. Decide relevant kind of information needed to test theory Start Again Glacier retreat, snow cover, rising sea levels, weather changes 3. Collect information by observation or experiment 4. Analyse information Analyse information 5. Consider result Consider result Theory provisionally corroborated 5.1. Theory provisionally corroborated 5.2.Falsification 5.2. Theory rejected 5.3. Expose to more stringent tests 5.4. Eventual falsification 5.5 New theory required incorporating good points of original theory and new information Tests etc.

40. Example: Global Dimming GLOBAL DIMMING? Formulate theory Stanhill measures irradiance levels over Israel in aid of irrigation schemes Decide relevant kind of information needed to test theory Start Again Network of light meters Collect information by observation or experiment Very serious reduction in sunlight Analyse information Consider result Consider result Theory conflicts with Global Warming, not accepted Theory provisionally corroborated Falsification Theory rejected Confirmation by German, Australian and other scientists Expose to more stringent tests Eventual falsification New theory required incorporating good points of original theory and new information Not falsified, incorporated into Global Warming theory Tests etc.

41. Thomas Kuhn Thomas Kuhn • Thomas Kuhn (1922-1996) stated that there are two types of knowledge or science, namely, core science and normal science • Core science is proven scientific knowledge, which scientists do not question, they do not try to falsify it • Normal science is the science that scientist do everyday to find answers, namely, the accumulation of data and to solve questions or puzzles Wikipedia Normal science Corescience

42. Normal Science Crisis Revolution Prescience Core Science and Normal Science • Normal science sometimes comes up with anomolies, which does not threaten the core science, for example global dimming was explained to be a symptom of climate change • However, as anomolies accumulate over time, scientists have to revisit what they previously held to be true • Eventually a crisis arises, where they can no longer ignore the anomalies, and must instead replace or modify the existing core science, e.g. Quantum Physics (green line) replaces Newtonian Physics (pink line)

43. Next Chapter Conclusion Chapter 1Review of Human Evolution Chapter 2History and Civilization Chapter 3 Philosophy of Science Chapter 4To be announced Chapter 5 To be announced Chapter 6 To be announced Chapter 7 To be announced Chapter 8 To be announced Chapter 9 To be announced I hope that you found chapter 3 informative, and that you enjoy chapter 4.