Available at http://planet.uwc.ac.za/nisl Philosophy of Science Faghrie Mitchell BCB 703: Scientific Methodology
Mar 13, 2016
Available at http://planet.uwc.ac.za/nisl
Philosophy of Science
Faghrie MitchellBCB 703:Scientific Methodology
Summary of section on ancient Egyptians
Ref:
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
SCIENCEPHILOSOPHY can
MYTHOLOGYRELIGIONDOGMA
can SCIENCEPHILOSOPHY can
MYTHOLOGYRELIGIONDOGMA
SCIENCEcan
What is Philosophy?
RefRobinson:
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).
What is Philosophy of Science?
RefRobinson:
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.
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: Hom
er
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
The Age of Mythology
RefRobinson:
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
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The Age of Mythology
RefRobinson:
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
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The Rise of Greek Philosophy
Wikipedia: 12 Gods of Olym
pus
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)
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
Wikipedia: Thalus of M
iletus
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
Wolfram
The Rise of Greek Philosophy
The Rise of Greek PhilosophyWikipedia: Plato
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: Aristotle
The Rise of PhilosophyWikipedia: Raphael’s School of Athens; www.hull.ac.uk
The Rise of Philosophy
RefRobinson:
Plato (on the left) pointing upwards: he is interested in the forms, universals, generals
Wikipedia: Raphael; www.hull.ac.ukW
ikipedia: Raphael
Aristotle (on the right): he is interested in particulars, specifics
The Rise of Philosophy: PLATO
Ref:fWikipedia
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
The Rise of Philosophy: ARISTOTLE
RefRobinson:
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
The Rise of Philosophy: ARISTOTLE
RefRobinson:
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.
Plato and Aristotle: Two Perspectives
RefRobinson:
Plato Aristotle
“Top down” approach
One starts with an idea
Theory laden observation
Rational traditionDEDUCTIVE REASONING
Bottom up approach
Drawing conclusions from observation
Empirical tradition
INDUCTIVE REASONING
Conclusion: Ancient Greek Philosophy
Ref:
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
MYTHOLOGYRELIGIONDOGMA
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The Rise of the Roman Empire
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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
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The Rise of the Roman Empire
Ref:
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
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The Rise of the Roman Empire
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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
The Decline of the Roman Empire
c. 400-526 CEBarbarian migrations and invasions
527-565 CEByzantium Empire under Justinian
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c. 632-750 CERise of Islam
The Byzantine and Islamic Empireswps.ablongman.com
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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
Preservation of Scholarship
Wikipedia: Al-Farabi
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: Avicenna
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”
www.multim
ediaquran.com
Wikipedia: Averoes
The Fall of the Byzantine Empire
Osprey
1453Siege mentality
Steady outflow of Byzantine-Greek scholars heading west
Increases scholarship in the West
Scholarship stopped in476 AD because1. disintegration ofpolitical structures 2. attack and invasions3. loss control of the Mediterranean and trade routes4. emergence of the Church
The Scientific Revolution 12th and 13th centuries The Renaissance 1543
Scientific 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: Copernicus
Wikipedia: Vesalius
The Scientific Revolution 1543
Emergence 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)
Descartes
Bacon
Galileo
Kepler
Plato Aristotle
“Top down” approach
One starts with an idea
Theory laden observation
Rational traditionDEDUCTIVE REASONING
Bottom up approach
Drawing conclusions from observation
Empirical tradition
INDUCTIVE REASONINGRene Descartes Sir Francis Bacon
Descartes (Platonic) vs Bacon (Aristotelian)
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)
12
3
Wikipedia
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: M
ute Swan(Cygnus olor)
Wikipedia: The Black Swan
(Cygnus atratus)
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
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01 January-24 December 25 December
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
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)
BaconW
ikipedia: Torquemada
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
DescartesBacon
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)
3
Wikipedia
12
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
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
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 induction
It asks logical questions knowledge (obtained via induction) I will show this by using the example of Global Warming and
Global Dimming
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Decide relevant kind of information
Formulate theory
Collect information by observation or experiment
Decide relevant kind of information needed to
test theory
Store information
Collect information by observation or
experiment
Develop generalisation
Analyse information
Formulate theoryConsider result
Seek verification of theory
State law or truth
Theoryprovisionallycorroborated
Falsification
Expose to more stringent tests
Theory rejected
Eventual falsification
Tests etc.
New theory required incorporating good points of
original theory and new information
StartAgain
1. Formulate theory
2. Decide relevant kind of information needed
to test theory
3. Collect information by observation or
experiment
4. Analyse information
5. Consider result
5.1. Theoryprovisionallycorroborated
5.2.Falsification
5.3. Expose to more stringent tests
5.2. Theory rejected
5.4. Eventual falsification
Tests etc.
5.5 New theory required incorporating good points of
original theory and new information
StartAgain
GLOBAL WARMING?
Glacier retreat, snow cover, rising sea levels, weather
changes
Glacier retreat, snow cover, rising sea levels, weather
changes
Analyse information
Consider result
Theoryprovisionallycorroborated
Formulate theory
Decide relevant kind of information needed to
test theory
Collect information by observation or
experiment
Analyse information
Consider result
Theoryprovisionallycorroborated
Falsification
Expose to more stringent tests
Theory rejected
Eventual falsification
Tests etc.
New theory required incorporating good points of
original theory and new information
StartAgain
GLOBAL DIMMING?
Stanhill measures irradiance levels over Israel in aid of
irrigation schemes
Network of light meters
Very serious reduction in sunlight
Consider result
Theory conflicts with Global Warming, not
accepted
Confirmation by German, Australian and other scientists
Not falsified, incorporated into Global Warming
theory
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
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)
Prescience
Crisis
Normal Science
Revolution
Chapter 1 Review of Human EvolutionChapter 2 History and CivilizationChapter 3 Philosophy of ScienceChapter 4 To be announced
Chapter 6 To be announcedChapter 5 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.
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