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Philosophy and Nature of Science. Part 1. Philosophy Part 2. Philosophers. Basic Questions. How do we know? What is knowing? Can we know with certainty? Can we believe something with certainty? Are there facts? Is there truth?

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Philosophy and nature of science l.jpg

Philosophy and Nature of Science

Part 1. Philosophy

Part 2. Philosophers


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Basic Questions

How do we know?

What is knowing?

Can we know with certainty?

Can we believe something with certainty?

Are there facts?

Is there truth?

Can an hypothesis be verified or falsified?


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What Constitutes Evidence?

Is there a relationship between evidence and hypothesis?

What evidence does one select to establish an hypothesis?


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How Does One Do SCIENCE?

Science does not adhere to the Baconian procedure of observation before hypothesis, hypothesis before testing.

It is more artistically driven. The scientist responds to an observed event by curiosity. The scientist follows up curiosity with persistence having no sure and fixed method to unravel the conundrum. Finally the researcher employs memory to relate one event to another and to avoid redundancy.


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Questions asked in the philosophy of science

  • Is science based on faith?

  • What is the scientific method?

  • How are new discoveries treated?

  • Is everything reducible to physics and mathematics?

  • Is everything reducible to a few rules?


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Science and Faith

Some Articles of Faith

Science is based on articles of faith:

The universe is consistent over space and time.

The universe is understandable.

We can understand the universe.

What’s valid here is valid there.

The universe is material and not spiritual

The universe is mathematical.

Experiment validates theory


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What Characterizes science?

  • A method for retaining reliable knowledge about the universe due to test and retest

  • Science is a testing community

  • Science seeks consistency not truth

  • Science tells the best minimal story about the universe. Pieces fit into a puzzle

  • Science does not ask why, but asks how, what, where, and when. Science seeks measurement


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Ideal Scientific Method

  • Observation

  • Repetition

  • Induction(1)

    Hypothesis

  • Deduction or generalization

    Consequence or prediction

  • Testing

  • Induction(2)

  • Induction (1) not successful


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Critique of the Ideal scientific Method

  • What’s observed and studied depends on the currently accepted explanation

  • Explanation selects the observation

    Explanation Influenced by:

    Brain hardware

    Gestalt formation

    Optical illusions

    Brain Software

    Education


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Induction

induction

Observation -----------------> Hypothesis


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Induction

  • Induction goes from effect to cause.

  • Effect can possibly have many causes.

  • A cause may have a single effect.

  • Hypothesis is a kind of cause

effect

cause


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Critique of Induction

  • There is no logical way of going from observation to hypothesis

  • Hypothesis is a simple guess

  • Frequently hypothesis precedes observation


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Hypothesis, Theory, Fact

  • Hypothesis are Guesses not logically derivable from deduction or Induction

  • Theories are statement of Probability

  • Facts do not exist- nothing is 100% certain


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Verification & Falsification

  • What is meant by explanation?

  • What is a fact?

  • When is a Fact verified?

  • How many observations needed?


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Deduction and Induction

induction

Observation ------------> Hypothesis

deduction

Hypothesis ------------> Observation


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Deduction

  • If there is no cogent way of going from observation to hypothesis

  • Then there is no cogent way of deducing from hypothesis to observation


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Critique of Deduction

  • Modern Science does not seek causes but seeks relationship among variables

  • Independent variables are not causes and dependent variables are not effects

  • If one knows Y =g(x), can one predict (deduce) the future?


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Verification and Falsification

  • Replace Verification with Falsification

  • Verification and falsification are asymmetrical

  • Multiple verification does not establish a theory more than a single verification

  • A single falsification overturns a theory

    It takes only one green swan overturns the theory that all swans are white. Observing one million white swans does no more to prove all swans are white than witnessing ten white swans.


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Falsification

  • It is nearly impossible to falsify an hypothesis.

  • Since a test depends on many factors it is difficult to determine whether the hypothesis failed or one of the other factors failed.

  • Some failures of dependent factors:

    precision and accuracy of instrumentation, correct interpretation of data, flawless recording of data, improper experimental conditions


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Transition to Immanuel Kant

Rationalism and Empiricism


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Historical Overview

Rationalism

Descartes

Spinoza

Leibniz

Wolff

Kant

Locke

Berkeley

Hume

Empiricism


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Empiricism

  • Basic tenets of Empiricism

    • All knowledge comes from experience

    • The mind is a blank slate (tabula rasa)

    • The mind is passive, merely a receptor of sense impressions

  • Hume’s radicalizes these, ending in Skepticism

    • Unbridgeable gap between sense impressions and objects in the world

    • All we know are ‘sensations’ playing in our minds

    • The necessary ‘connectedness’ of experience is problematic Causality is merely superstition, born of habit


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Rationalism

  • Basic tenets of Rationalism

    • Reason has access to reality as it really is

    • Reason can go beyond what is given to us in experience

    • Reason can then grasp things, not as they appear, but as they really are

  • The Leibniz-Wolffian School

    • Reason (without experience) can know about God, immortality of the soul, and human freedom

  • Reason has direct access to “meta-physical” knowledge


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Part 2

  • John Locke

  • David Hume

  • Immanuel Kant

  • Thomas Bayes

  • Karl Popper

  • Thomas Kuhn

  • Imre Lakatos


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John Locke (1632-1704)

Introduction



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Biography

  • B. 1632, son of a small property-owner and lawyer

  • Oxford, 1652-67

  • Studied church-state issues, chemistry and medicine, new mechanical philosophy

  • Involvement in politics through Lord Ashley, whom he treated for a liver abscess

  • Plotted to assassinate King Charles II and his Catholic brother, later James II

  • Exile in Holland, 1683-89

  • 1689: 3 major works published


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Major works and themes:

A Letter Concerning Toleration (1689)

  • Argues for religious toleration;

  • Except for atheists, “who deny the Being of a God” and thus cannot be trusted to keep their promises (e.g. in contracts).

    Context:

    - Religious wars and persecution in England and on the Continent.


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Works, cont.

Essay Concerning Human Understanding (1689)

  • Argues against innate ideas

  • For the acquisition of knowledge through the senses: “Intuitionism”

  • Anti-Cartesian (Descartes)

  • Re-opens debate about essentialism vs conventionalism with his views on identity, comparison, classification and natural kinds.


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Works, cont.

Two Treatises on Government (written 1679/80; published 1689/90)

  • First: Argues against traditional basis for political authority expressed in Filmer’s Patriarcha, divine right of kings;

  • Second: protection of private property, life and liberty = basis for civil government.


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Locke’s Basic Epistemology

  • Human being = tabula rasa (blank slate)

  • receives sense-impressions

  • some of these transformed by Mind into Ideas

  • Ideas represented in language by words

  • However, no Ideas are innate

  • Mind operates (through gradual learning process) w/out reference to any received authority (of Church, State or others)


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Complex Ideas

  • Sense-data of primary qualities (PQs) and secondary qualities (SQs), produce ideas in the mind:

  • Ideas are mental results of sense-data

  • -Sense-perceptions

  • -Bodily sensations

  • -Mental images

  • -Thoughts and concepts


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Primary(PQ) and Secondary Qualities(SQ)

Distinction between perceived aspects of things. The primary qualities are intrinsic features of the thing itself (its size, shape, internal structure, mass, and momentum, for example), while the secondary qualities are merely its powers to produce sensations in us (its color, odor, sound, and taste, for example). This distinction was carefully drawn by Galileo, Descartes, Boyle, and Locke, whose statement of the distinction set the tone for future scientific inquiry. But Foucher, Bayle, and Berkeley argued that the distinction is groundless, so that all sensible qualities exist only in the mind of the perceiver.


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Attacks Innatism (Descartes)

Locke’s objections to innate ideas (“II’s”)

  • Lack of universal assent: II’s not known to idiots, children, illiterates

  • Dependence on authority:

  • “…a Man is not permitted without Censure to follow his own Thoughts in the search of Truth, when they lead him…out of the common Road”.

  • Epistemological and political commitment to the individual (who is the foundation of Locke’s political liberalism).


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Revised, 11/21/03

David Hume(1711-1776)

An Inquiry Concerning Human Understanding


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Anthem1

Anthem2


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1. Sensation & the Origin of Ideas

  • The contents of the mind: (1) ideas & (2) impressions (sensations & feelings) -- Ideas (concepts, beliefs, memories, mental images, etc.) are faint & unclear; impressions are strong & vivid.

  • Ideas are derived from impressions: All ideas are copies of impressions.

  • The meaning of ideas depends on impressions


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The empirical criterion of meaning

"From what impression is that alleged idea derived?"

No impression, no meaning?

No impression, no foundation in reality?



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Two kinds of ideas(or judgments)

"All the objects of human reason or inquiry may naturally be divided into two kinds: relations of ideas and matters of fact".

"Hume's Fork"


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Judgments concerning relations of ideas

Ideas

("Hume's Fork")

Judgments concerning matters of fact


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Judgments concerning relations of ideas

  • Intuitively or demonstrably certain

  • Discoverable by thought alone [a priori]

  • Cannot be denied without contradiction

*Hume's examples: Pythagorean Theorem

or

3 x 5 = 30  2


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The Pythagorean Theorem

On a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides

5'

4'

(hypotenuse)

32 + 42 = 52

(9 + 16 = 25)

3'


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Judgments concerning matters of fact

  • "Every judgment concerning matters of fact can be denied without contradiction" (e.g., "the sun will not rise tomorrow").

  • Neither intuitively nor demonstrably certain

  • Not discoverable by thought alone [a priori], but rather on the basis of sense experience [a posteriori]

More specifically,


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All judgments concerning matters of fact are based on . . . .

the more fundamental] belief that there is "a tie or connection" between cause & effect.


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And why do we believe that there is a "tie or connection" between cause & effect?

Answer: The belief arises entirely from experience [a posteriori, not a priori], namely, the experience of finding that two events (cause & effect) are "constantly conjoined" with each other.


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It is not between cause & effect?logically necessary that a particular effect follows a particular cause;

it is just a fact of experience.

This view leads to Hume's discussion of . . . .


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3. The Nature & Limits of Inductive Reasoning between cause & effect?

(the problem of induction)


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Hume on Induction between cause & effect?

  • Induction is the process of drawing inferences from past experiences of cause & effect sequences to present or future events.

  • Hume's point is that an "effect" cannot be validly deduced from its "cause;"

  • the inference from "cause" to "effect" is based on past experiences of "constant conjunction," and these past experiences . . . .


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accustom between cause & effect? or habituate us

to believe that one event is the cause of another, which we believe to be the effect of the prior event.

This is what leads us to believe that . . . .


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the future will resemble the past. between cause & effect?

It is all a matter of CUSTOM or HABIT.

This is the foundation of . . . .


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The Idea that there is a Necessary Connection between Cause & Effect

If this is a meaningful (& true?) idea, then (according to Hume) it must be derived from sense impressions.

What, then, is the sense impression from which this idea is derived?


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There is no sense impression of & Effectcausal power or necessary connection of cause & effect, but we do experience . . . .

  • (1) the spatial contiguity,

  • (2) the temporal succession, and

  • (3) the constant conjunction

of "cause" & "effect."


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It is from this experience, & Effect

  • especially the experience of constant conjunction,

  • that the idea of a necessary connection between "cause" & "effect" arises (or is inferred);

  • but the "inference" is simply a matter of "custom or habit."

    • This seems to mean that the "inference" here is psycho-logical rather than logical. Actually, there is no experience of the necessary connection between cause and effect. Thus, all factual judgments (which are based on the assumption that there is a necessary connection between cause and effect) are subject to doubt.

    • No necessity, no certainty.


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Immanuel Kant & Effect

• 1724-1804

• Lutheran (Pietist) background

• “Second Copernican Revolution” in philosophy

• Spent all his life in Königsberg, a small German town on the Baltic Sea in East Prussia. (After World War II, Germany's border was pushed west, so Königsberg is now called Kaliningrad and is part of Russia.)

Groundwork of the Metaphysics of Morals


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Immanuel Kant & Effect

• At the age of fifty-five, Kant had published much work on the natural sciences, taught at Königsberg University for over twenty years, and achieved a good reputation in German literary circles.

• During the last twenty-five years of his life, however, Kant's philosophical work placed him firmly in the company of such towering giants as Plato and Aristotle.

Groundwork of the Metaphysics of Morals


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Immanuel Kant & Effect

• Kant's three major works are often considered to be the starting points for different branches of modern philosophy:

the Critique of Pure Reason (1781) for the philosophy of mind;

the Critique of Practical Reason (1788) for moral philosophy;

and the Critique of Judgment (1790) for aesthetics.

Groundwork of the Metaphysics of Morals


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Immanuel Kant & Effect

• The Grounding for the Metaphysics of Morals was published in 1785, just before the Critique of Practical Reason.

• It is essentially a short introduction to the argument presented in the second Critique.

Groundwork of the Metaphysics of Morals


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Kant’s Intellectual Climate & Effect

• Kant lived and wrote during the Enlightenment. This period produced the ideas about human rights and democracy that inspired the French and American revolutions. (Some other major figures of the Enlightenment were Locke, Hume, Rousseau and Leibniz.)

• The characteristic quality of the Enlightenment was an immense confidence in reason, i.e. humanity's ability to solve problems through logical analysis. The central metaphor of the Enlightenment was a notion of the light of reason dispelling the darkness of mythology and misunderstanding.

Groundwork of the Metaphysics of Morals


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Kant’s Intellectual Climate & Effect

• Enlightenment thinkers like Kant felt that history had placed them in the unique position of being able to provide clear reasons and arguments for their beliefs.

• The ideas of earlier generations, they thought, had been determined by myths and traditions; their own ideas were based on reason.

Groundwork of the Metaphysics of Morals

(According to this way of thinking, the French monarchy's claims to power were based on tradition; reason prescribed a republican government like that created by the revolution.)


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Kant & Effect

• Kant's philosophical goal was to use logical analysis to understand reason itself. Before we go about analyzing our world, Kant argued, we must understand the mental tools we will be using.

• In the Critique of Pure Reason, Kant set about developing a comprehensive picture of how our mind – our reason – receives and processes information.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• Kant later said that the great Scottish philosopher David Hume (1711-1776) had inspired him to undertake this project. Hume, Kant said, awoke him from an intellectual "slumber."

• The idea that so inspired Kant was Hume's analysis of cause-and-effect relationships.

Groundwork of the Metaphysics of Morals


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Hume & Effect

According to Hume, when we talk about events in the world we say that one thing ‘causes’ another.

But nothing in our perceptions tells us that anything causes anything else. All we know from our perceptions is that certain events regularly occur immediately after certain other events.

‘Causation’ is just a concept that we employ to make sense of why certain events regularly follow certain other events.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• Kant took Hume's idea and went one step further. Causation, Kant argues, is not just an idea that we employ to make sense of our perceptions. It is a concept that we cannot help but employ. We don't sit around watching events and then develop an idea of causation on the basis of what we see. We automatically bring the concept to bear on the situation.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• Kant argued that causation and a number of other basic ideas (e.g., time and space) are hardwired, as it were, into our minds. Anytime we try to understand what we see, we cannot help but think in terms of causes and effects.

Groundwork of the Metaphysics of Morals


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Kant & Effect

Kant's argument has huge implications. If our picture of the world is structuredby concepts that are hardwired into our minds, then we can't know anything about how the world ‘really’ is.

The world we know about is developed by combining sensory data (‘appearances’ or ‘phenomena,’ as Kant called them) with fundamental concepts of reason (‘causation,’ etc.).

We don't know anything about the ‘things-in- themselves’ from which sensory data emanates.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• This recognition that our understanding of the world may have as much to do with our minds as with the world has been called a “Copernican Revolution” in philosophy – a change in perspective as significant to philosophy as Copernicus’s recognition that the earth is not the center of the universe.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• Kant's insights posed a severe challenge to many earlier ideas.

Ex.: Before Kant many philosophers offered ‘proofs’ of the existence of God.

One argument made was that there must be a

"first cause" for the universe. Kant pointed out that the question of whether there "must" be a first cause for the universe is irrelevant, because it is really a question about how we understand the world, not a question about the world itself.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• Kant’s analysis similarly shifted the debate over free will and determinism. (Kant presents a version of this argument in Chapter 3 of the Groundwork.)

When we use reason to understand why we have made the choices we have, we can come up with a causal explanation. But this picture is not necessarily accurate. We don't know anything about how things "really" are; we are free to think that we can make free choices, because for all we know this might "really" be the case.

Groundwork of the Metaphysics of Morals


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Kant & Effect

• In the Critique of Practical Reason and the Grounding for the Metaphysics of Morals, Kant applies this same technique –using reason to analyze itself – to determine what moral choices we should make.

• Just as we cannot rely on our picture of the world for knowledge about how the world "really" is, so also we cannot rely on expectations about events in the world in developing moral principles. Kant tries to develop a moral philosophy that depends only on the fundamental concepts of reason.

Groundwork of the Metaphysics of Morals


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Kant’s Intellectual Climate: Criticisms & Effect

Some later thinkers have criticized Enlightenment philosophers like Kant for placing too much confidence in reason. Some have argued that rational analysis is not the best way to deal with moral questions.

Further, some have argued that Enlightenment thinkers were pompous to think that they could discover the timeless truths of reason; in fact, their ideas were determined by their culture just as all other people’s are.

Groundwork of the Metaphysics of Morals


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Karl & EffectPopper

  • Popper replaces induction with falsification

  • Science is not distinguished from non-science on basis of methodology. No unique methodology specific to science

  • Science consists mostly of problem solving.


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Karl & EffectPopper

  • All observations are selective and theory laden

  • A demarcation between science and pseudo-science is established by falsification. A theory is scientific only if it is refutable by a conceivable event

  • Every genuine test of a scientific theory is based on an asymmetry between verification and falsification


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Sir & EffectKarlPopper (1902-1994)

  • Falsification is the idea that science advances by unjustified, exaggerated guesses followed by unstinting criticism.

  • Any "positive support" for theories is both unobtainable and superfluous; all we can and need do is create theories and eliminate error

  • Scientists never actually use induction. It is impossible to verify propositions by reference to experience


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Falsificationism (1) & Effect

Scientific Method

  • Is there a scientific method?

  • What justifies scientific claims to knowledge?

  • Can we distinguish scientific method from non-scientific ways of thinking? (demarcation)

  • Does science progress?


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Falsificationism (1) & Effect

Falsificationism ‘No criterion of truth’:

Two Arguments:

  • No Theory/observation distinction:

    • ‘Here is a glass of water’ is theory laden

    • In accepting the statement we must accept a significant amount of theory

    • We have only as much justification for accepting the observation statement as we do for the theory


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Falsificationism (1) & Effect

Falsificationism ‘No criterion of truth’:

Two Arguments:

  • No Theory/observation distinction:

    Upshot: we cannot use observation to establish the truth of a theory

    How can we establish the truth of scientific theories?

    We can’t!


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moon & Effect

Falsificationism (1)

Confirmation and Pseudoscience

Good scientific practice:

E.g. Einstein’s general relativity

Conjecture: mass of the sun bends the path of light

Apparent location

Actual location


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Falsificationism (1) & Effect

Confirmation and Pseudoscience

Good scientific practice:

E.g. Einstein’s general relativity

Conjecture: mass of the sun bends the path of light

  • If the apparent location of the observed star doesn’t shift, the theory is wrong.

  • It will have been refuted.

  • The mark of a scientific theory is whether it can be falsified by observation


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Falsificationism (1) & Effect

Conjecture and Refutation:

“Falsificationists… prefer an attempt to solve an interesting problem by a bold conjecture, even (and especially) if it soon turns out to be false, to any recital of a sequence of irrelevant truisms” (CR: 231)

This gives us:

(i) a glimpse of scientific method

(ii) a demarcation criterion for science


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Falsificationism (1) & Effect

Scientific method:

Scientific theories have deductive consequences

  • They can be falsified but not confirmed.

  • The objective of scientific theorizing is to put forward (bold) hypotheses and then test them in order to falsify them

  • Theories are falsified by basicstatements

    (what is a basic statement?)


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Falsificationism (1) & Effect

Demarcation:

  • Scientific theories are those that can be falsified by basic statements.

  • Good scientific theories do not make themselves immune from falsification by use of ad hoc hypotheses


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Falsificationism (1) & Effect

Progress of Science:

  • Science progresses by eliminating theories that have been falsified?

  • But does it progress?

  • A scientific theory cannot be shown to be true. But some scientific theories do have varying degrees of success. They resist falsification.


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Falsificationism (1) & Effect

“We must not look upon science as a body of ‘knowledge’, but rather as a system of hypotheses which in principle cannot be justified, but with which we work as long as they stand up to tests, and of which we are never justified in saying that we know that they are ‘true’, or ‘more or less certain’ or even ‘probable’


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Kuhn & Effect(1)

Thomas Kuhn

(1922-1996)

The Copernican Revolution (1957)

The Structure of Scientific Revolutions (1962)

  • History of science not compatible with rationalist view

  • Progress of science not cumulative, driven by the application of a method


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Kuhn & Effect(1)

Thomas Kuhn

(1922-1996)

The Copernican Revolution (1957)

The Structure of Scientific Revolutions (1962)

  • No obvious science/non-science demarcation

  • No context of discovery/context of justification distinction


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Kuhn & Effect(1)

Kuhn’s History of Science

Two projects:

  • Descriptive — what is the structure of scientific history?

    Normal science Scientific revolution

  • Explanatory — why does the history of science have this structure?

    Paradigms


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Descriptive Project:

Immature Science

Revolution

Normal Science

Crisis

Anomalies


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Paradigm Diagram & Effect

old paradigm unexplained observations competing new

paradigms

incommensurate

puzzle solving

one dominant paradigm

Mopping up operation

unsolved puzzles ignored

unexplained observations

unexplained observations and alternative interpretation ignored until enough accumulates to overturn current paradigm


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Immature Science:

No prevailing school of thought

Various disparate theories

Competition


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Normal Science:

  • Stability

  • Determination of significant facts

  • Matching facts with theories

  • Articulation of theories (refinement and extension)

    “puzzle -solving” neither tests nor confirms its theories


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Normal Science:

  • Driven by a paradigm (more later):

  • Commonly held set of beliefs, procedures, techniques

  • Agreement upon questions of import

  • Agreement on what counts as a solution

  • Agreement upon standards of evaluation


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Anomalies:

Not all expectations are borne out

  • Some anomalies lead to further discoveries (e.g. orbit of Uranus)

  • Some simply ignored

  • Troublesome anomalies

    Challenge key theoretical concepts

    Resist solutions

    Inhibit application of theory


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Crisis:

  • Weight of accumulated anomalies

  • No agreement on how anomalies are to be dealt with

  • Doubts arise


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Revolution:

A new paradigm emerges

Old Theory: well established, many followers, politically powerful, well understood, many anomalies

New Theory: few followers, untested, new concepts/techniques, accounts for anomalies, asks new questions


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Kuhn & Effect(1)

1. Kuhn’s History of Science

Revolution:

A new paradigm emerges

Are old and new theories compared by some rational procedure?

“A new scientific theory does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it” (Planck)


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Kuhn (1) & Effect

Scientific Revolutions

The Ptolemaic model

The earth is at the centre of the planetary system

Problem:

How to explain the retrograde motion of planets


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Kuhn (1) & Effect

Scientific Revolutions

The Ptolemaic model

The earth is at the centre of the planetary system

Problem:

How to explain the retrograde motion of planets

Deferent

Earth

Planet

Epicycle


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Kuhn (1) & Effect

Scientific Revolutions

The Ptolemaic model

http://csep10.phys.utk.edu/astr161/lect/retrograde/aristotle.html

The earth is at the centre of the planetary system


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Kuhn (1) & Effect

Scientific Revolutions

The Ptolemaic Model:

Problems:

  • Complexity: epicycle upon epicycle

  • The accumulation of anomalies

  • No clear way forward


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Kuhn (1) & Effect

Scientific Revolutions

The Copernican model

The sun is at the centre of the planetary system

Problem:

How to explain the retrograde motion of planets


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Kuhn (1) & Effect

Scientific Revolutions

The Copernican model

http://csep10.phys.utk.edu/astr161/lect/retrograde/copernican.html

The sun is at the centre of the solar system


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Kuhn (1) & Effect

Scientific Revolutions

The Copernican Revolution was not the consequence of an old theory with less ‘empirical content’ being replaced by a new theory with more

  • No appeal to reason alone

  • ‘propaganda’

    To discover how scientific revolutions are effected, we shall therefore have to examine … the techniques of persuasive argumentation within the quite special groups that constitute the community of scientists (SSR: 94)


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Kuhn (1) & Effect

2. Explanatory Project

Two Questions:

  • If this is the course of the history of science, why?

  • Why aren’t competing theories/traditions measured against each other by some rational procedure?


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Kuhn (1) & Effect

2. Explanatory Project

Paradigms

Disciplinary Matrix:

(i) Symbolic generalisations

(ii) Metaphysical commitments

(iii) Scientific values

(iv) Heuristic models

(v) Exemplars


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Kuhn (1) & Effect

  • Explanatory Project

    Why is normal science stable?

    It is conducted wholly within the terms of a disciplinary matrix:

    questions

    procedures

    problems

    priorities

    standards of evaluation

    All are generated by the disciplinary matrix


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Kuhn (1) & Effect

  • Explanatory Project

    Why is theory change revolutionary?

    Theory change is brought about by a ‘gestalt switch’ a complete change of world view

    There is no neutral point from which one can assess theories from two paradigms simultaneously


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Thomas Kuhn (1922-1996) & Effect

  • All research presupposes a world-view,a collection of fundamental objects, natural laws, definitions, and above all a definition of what research is.

  • Kuhn called a world-view, paradigms

  • Mature science have established paradigms

  • Example of mature sciences are chemistry, physics, geology; whereas, economics and psychology are

    immature sciences.


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Paradigm & Effect

  • Thomas Kuhn popularized the term in his book The Structure of Scientific Revolutions (1996) by using it to describe how science works. According to Kuhn, scientific explanations of the world are controlled by a paradigm, some model of how the world is expected to work and into which actual observations are fitted, even if the fit is not very exact. As inexact fits accumulate, it becomes more apparent that the dominant paradigm is inadequate as a model of reality. When enough contradictions exist, a paradigm revolution occurs and a new paradigm is adopted.

  • The word paradigm comes from the Greek paradeiknunai and means "to compare." In science and philosophy it has the same basic meaning as in common usage: a model or instance used as a basis or example for further work.


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Need for Paradigms & Effect

  • Research requires paradigms

  • Paradigms are models of the way the world works

  • Without paradigms research is a random collection of observations lacking unification of structure into a whole.

  • Without paradigms, it is not possible to decide which are and which are not important observations


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Dominant Paradigms & Effect

As a field matures, one paradigm becomes the dominant one. Once paradigms is established research progresses quickly


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Paradigm guides direction of Research & Effect

It becomes clear with aid of paradigm which research areas are fruitful. These areas are ones not totally explained

Paradigms give concepts and laws to build on.


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Paradigm Shift & Effect

Paradigm shift occurs when old paradigm shown inadequate

What is defined as research is reevaluated

Concepts turn upside down. Earlier research is

reinterpreted


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Real research & Effect

  • Real Research occurs during a paradigm shift

  • Once a paradigm dominates, research becomes puzzle solving

  • Puzzle solving is not research due to answers known beforehand


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Example of Puzzle Solving & Effect

After Newton explained solar system, later scientists using Newton’s theory predicted

The presence of the then unknown planets

Neptune, Uranus, and Pluto


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What New Paradigms Do & Effect

  • Discovery of new paradigm results in new questions being asked and old questions abandoned

  • Newton saw gravitation as a property of matter. Earlier theories tried to find a mechanical explanation as whirlpools in space or angels.


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Paradigms are Incommensurable & Effect

  • Paradigms have different world view. It is difficult to compare them

  • Consequently, science defines truth relative to a paradigm and not absolutely. Truth is a story


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Science & Effect

  • Science is a conformist society which present only the currently accepted theory

    Consequently science defines reality relative to the accepted paradigm

  • Students are educated into the accepted paradigm and to ignore alternative paradigms

  • The society of science determines what scientists observe


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Imre Lakatos & Effect(1922 - 1974)`

  • All scientific theories are equally un-provable

  • Falsification doesn’t work due to rescue hypotheses

  • the "basic unit" of scientific development is not the scientific theory, such that science progresses when one theory proves to be more successful than another.


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Imre Lakatos & Effect

the "basic unit" is actually the research program. Science progresses when one research program becomes more productive and more useful than other and, hence, receives a greater share of social resources through funding and younger scientists looking to join. A research program is characterized by a particular set of "hard core" fundamental ideas and is deemed successful so long as it contents continue to increase.


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Imre Lakatos & Effect

  • In reality scientists do not abandon theories. They invent rescue hypotheses or ignore anomalies or refutations

  • Popperian crucial experiments and Kuhnian revolutions turn out to be myths. What happens is progressive research replaces degenerating ones.

  • Progressive scientific programs predict and produce dramatic, unexpected observations and results


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Falsificationism & Effect

Popper

Science progresses toward its goal of increasing verisimilitude by advancing bold conjectures and then attempting to refute these by observations

  • Theories cannot be verified by observation

    —anti-inductivism

    —no theory/observation distinction

  • Theories are falsified by basic statements

  • We choose between theories on grounds of corroboration (mark of verisimilitude)


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Falsificationism & Effect

Problems for Falsificationism (recap)

Falsification:

Some legitimate features of scientific enterprise are not falsifiable:

  • Probabilistic Statements

  • Existential Statements

  • Metaphysical Commitments


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Falsificationism (finale) & Effect

Problems for Falsificationism

3. Basic Statements:

Theories are falsified by basic statements.

What warrants our acceptance of basic statements?

(i) Observation?: No. Basic statements are theory laden. Accepting them requires accepting theory

(ii) Decision/convention: not grounded in a rational procedure


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Falsificationism (finale) & Effect

‘Whiff of Inductivism’

A Dilemma for Popper:

  • Give up on induction

    —No rational criterion for choosing between competing theories

    —No rational grounds for continuing to use successful theories

  • Give up the distinctive features of falsificationism


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Falsificationism (finale) & Effect

Problems for Falsificationism

3. Basic Statements:

Theories are falsified by basic statements.

What warrants our acceptance of basic statements?

(i) Observation?: No. Basic statements are theory laden. Accepting them requires accepting theory

(ii) Decision/convention: not grounded in a rational procedure


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Scientific Research Programmes & Effect

Revision versus Ad hoc Hypotheses

Two questions

In the light of anomalies:

  • What should one change?

    Principle of least change

    (ii) When should one abandon a theory(in favour of another)?


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Scientific Research Programmes & Effect

Scientific Research Programmes (SRP)

A theory is:

  • Rules of logic and mathematics

  • Metaphysical commitments

  • Statements of laws

  • Assumptions about initial conditions

    A SRP is a lineage of theories. SRP evolve over time

    Rules according to which SRP’s evolve over time.


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Scientific Research Programmes & Effect

Scientific Research Programmes (SRP)

Parts of a SRP:

Hard Core:

Theoretical assertions

Metaphysical commitments

HC

Auxiliary Belt:

Initial conditions

Assumptions

Ad hoc hypotheses

AB


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Scientific Research Programmes & Effect

Scientific Research Programmes (SRP)

Parts of a SRP:

e.g. Celestial Mechanics

Hard Core:

Laws of Motion

Universal Gravitation

Space and time

HC

Auxiliary Belt:

Number of planets

Masses of planets

AB


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