Lecture1_2015

The History and Philosophy of ScienceThe history of science

Why is the history ? I conclude that natural science as a form of thought exists and always has existed in a context of history and depends on historical thought for its existence. From this I venture to infer that no one can understand natural science unless he understands history

The Idea of Nature R.G. Collingwood

The history of science

the study of scientific knowledge natural sciences (physics, chemistry, biology, and mathematics)

The Philosophy of Science what is the aim/s of science?,what is its method/s?, what is science?,how does it differ from non-science (religion & philosophy) and pseudo-science (astrology, phrenology, voodoo, etc.)?

The Philosophy of Science what is a scientific theory and how do scientific theories relate to the world?,how do theoretical concepts get their meaning and how are they related to observation?

scientific knowledge Derive through objective human construct

How does scientific knowledge grow ?Traditional answer by humans finding out true (or at least confirmed) knowledge.Current answer by humans constructing the best current knowledge

How does scientific knowledge grow ? a traditional answer a current answerknowledge is that which has been proven (or confirmed)knowledge is never confirmable, certainly not probableassumed by some to be acquired primarily by by mans finding out true or at least confirmed knowledge by mans constructing the best current knowledgeassumes assumesassumed by someto be acquiredprimarily byevidence of the sensespower of the intellectconstructivismEmpirism & positivismrationalismBaconComteLockeHuneHenpesDescartesKantIs divided on the issue ofWhat should determine the selection of best Current knowledgeSome maintain that these areSome maintain that these areInner disciplinary: criteria(rational, logical, empiricalOuter disciplinary: factors/values(social-psychological, historicalPopperLakatosToulminKuhn

Traditional AnswerAssumes knowledge is what has been proven (or confirmed)

Traditional answerthis is assumed by some to be acquired primarily by evidence of the senses empirism & positivism (scientific knowledge is derived from the fact of experience, but positivism somewhat broader and less psychological view of what facts amount to).

Traditional Answerthis is assumed by some to be acquired primarily by power of the intellect rationalism

Objective Knowledge

Discovered by empirical means scientific theories practical Through the use of scientific methods (careful observation and experimentation can lead to discovery of truths about how the world works)

Practical Knowledge

Procedural knowledge how to solve problems.declarative knowledge problem solving through experience of doing things.

Empirical means Knowledge derives from evidence through the use of hypothesis and testable experimentAxioms or postulates, deductive,

Scientific Theories

scientific knowledge that reliable, rigorous, and comprehensive. this knowledge empirically support (verify) or empirically contradict (falsify).

The Historical and Philosophical Contexts

Schools of thought: empiricism; positivism; pragmatism; rationalism; transcendentalism

Empiricism 17th British philosophy all knowledge is derived from sensory experience (observing and experimenting)Bacon, Locke, Hume are the philosophers.

Pragmatism 19th century American thinking the meaning or value of an idea/ knowledge lies only on its practical consequenceJohn Dewey (1859 -1952)

Rationalism 17th century, European philosophy reason is the only source of knowledge.Gottfried von Leibniz (1646 -1716)

Transcendentalism 19th century, American philosophy knowledge beyond the limits of experience Kant ( - ) & Henry David Thoreau (1817 1862)

Empiricism The philosophy term employed that knowledge derived from our experiences or observations.Then, hypothesis and testable experiment are used before scientific statements are accepted scientific knowledge.

PositivismIn the 19th Century the Baconian-cum-empiricist held that scientific knowledge was the only authentic kind of knowledge, and that all other purported forms of knowledge religion, metaphysics etc. were in fact meaningless nonsense

How would you currently define science?

PositivismThe Baconian of science emphasized the role of empirical observation and experiment as the distinctive feature of the scientific method: controlled observation and experiment was the basic, and built up by inductive inference.

PositivismThis account implied a directly view of science (nature in reality as empirical science), and the scientist plays a passive role in that he simply discovers the laws that already there, inscribed in nature.

Humes Naturalism 17 century (1711 -1176)The British empiricist who held that all knowledge should derived from ideas implanted in the mind by way of sense perception, that is the knowledge of the world that we get through the senses of light, touch, hearing, smell, and so on.

Inductivism

Science as knowledge derived from the facts of experience: a widely held common sense view of science; nave inductivism; logic & deductive reasoning; prediction and explanation in the inductivist account.

A widely held commonsense view of science Facts are directly given to careful, unprejudiced observers via the senses - seeing is believing - visual experiences not determined solely by the object viewed - observable facts expressed as statements

A widely held commonsense view of scienceFacts are prior to and independent of theoryFacts constitute a firm and reliable foundation for scientific knowledge

Seeing is believingThe sense of sight is used to observe the world. The account of observation incorporated into empiricist view of science can be seen i. a human observer has more or less direct assess to knowledge of some facts about the world insofar as they are recorded by the brain in the act of seeing

Seeing is believingii. Two normal observers viewing the same object from the same place will see the same thing.

Visual experiences not determined solely by the object viewedTwo normal observers viewing the same object from the same place do not necessarily have identical visual experiences, or two observers need not see the same thing.

Visual experiences not determined solely by the object viewedObservers viewing the same scene from the same place see the same thing but interpret what they see differently. Although the cause of what is seen resulted from the images form on the retinas, cause resulted from the inner state of his/her mind or brain depends on his/her cultural upbringing, knowledge, and expectations.

Visual experiences not determined solely by the object viewedThe dependence of observing on the state of mind or brain is not so sensitive, thus communication and science become impossible. Although all observers have a sense in which they are confronted by, look at, and hence see, the same thing, but it does not follow from this that they have identical perceptual experiences.

Visual experiences not determined solely by the object viewedThus, what observers see, the subjective experiences that they undergo, when viewing an object is not determined solely by the images on their retinas, but depends also on experience, knowledge, and expectations of the observer

Observable facts expressed as statementsRecording observable facts, not only requires the reception of the stimuli, but also requires the knowledge of appropriate conceptual scheme and how to apply it.

Facts are prior to theoryScience is derived from the facts scientific knowledge is constructed by establishing the facts, then building the theory to fit them.These perceptions depend on prior knowledge, state of preparedness, and expectations.

Nave InductivismScience starts with observation, the observer should have normal, unimpaired sense organs, faithfully record what s/he can see, hear, touch, taste to be the case with respect to the situation s/he is observing, and do this with unprejudiced mind.

Nave Inductivismthe observation statements then form the basis from which the laws and theories that make up scientific knowledge to be derived. This singular statements refer to a particular occurrence or state of affairs at a particular place at a particular time.

Nave InductivismUniversal statements refer to all events of a particular kind at all places and atall times. For example, all planets wherever they are situated, always move in ellipses around their sun.

The problems of induction & other problems with inductivismScientific methods in science is considered as nave inductivism. Nave inductivist argues that science starts with observation.

The problems of induction & other problems with inductivismIn other words, scientific knowledge is derived from observation. The problems of this scientific methods cast on the validity and justifiability of the principle of induction.

The problems of induction & other problems with inductivismInductive arguments are not logically valid arguments, and thus cannot be justified purely on logical grounds it is not the case that, if the premises of an inductive inference are true, then the conclusion must be true. It is possible for the conclusion of an inductive argument to be false and for the premises to be true, and yet for no contradiction to be involved.

The problems of induction & other problems with inductivismobservations be made under a wide variety of circumstances

Logic and deductive reasoning Once scientist has universal laws and theories at his/her disposal, then it is possible for him/her to derive from them to make explanations and predictions, The kind of reasoning in derivations of this kind is called deductive reasoning.

Deductive the process of reasoning from one or more general statements about what is known before conclusion is made. here, true premises are used.

Scientific methods Knowledge acquired by means of experiment observation, explanation, and prediction

Current AnswerKnowledge is never confirmable, certainly not provable constructivism

Current AnswerThis thought is divided on the issue of what should the selection of best current knowledge - some maintain that these are inner disciplinary criteria (rational, logical, empirical) - some maintain that these are disciplinary factors/values (socio psychological, historical)

FalsificationismThis term also called as hypothetico-deductivism as a methodology of science This thought emphasizes the demarcation between science and metaphysics, and the description of scientific method.

FalsificationismAccording to Popper, the first is denying the status of science to Marxism and certain type of social science, whereas the second is unorthodox, concerned as it is with the scientists treatment of his/her theoretical ideas, rather than their framing.

Falsificationismscientific statements must be testable or falsifiable - deduction of consequences from the theory, which consequences have the form of singular statements - the basic statements of the science in question must be identified (theoretical elements)

Falsificationismby accepting theses statements, the scientist makes them and their associated theories unfalsifiable. scientific statements must remain tentative forever.

Conjectures and Refutationsthe hypothetico-deductive system originates from logical positivism, a school of philosophy according to which no statement about the world could be meaningful unless it was, at least in principle, empirically verifiable. this system emphasizes the importance not of verifying new ideas but of trying to falsify them empirically.

FalsificationismAs the account of science became more and more discrepant with the actual practice of science in the 19th century and 20th century, the complex and abstract theories developed, especially in physics, were not clearly inferred from sensory observations.

FalsificationismFor example, the entities postulated by these theories elementary particles, waves, fields, etc. did not exist in actual reality, but in fact models or metaphorical devices which were justified in terms of their usefulness in probing the secrets of nature.

FalsificationismWhen it is said that light has a wave structure, meaning that light behaves, in some respect, as if it had a wave structure. Thus, the scientist is no longer seen as a passive observer discovering the law of nature that are already there awaiting him, but instead having an active and creative role in the construction of scientific theories.

FalsificationismThese aspects of scientific practice, emphasize on the theoretical superstructure, and not on observational base

Falsificationism There cannot be any direct connection between the observations and the generalisations (laws and theories) of science.

Falsificationism Inductive inference cannot be made from a limited number of observations about particular things to unrestricted generalisation about all things of a certain class. Thus, according to falsificationist, inductive inference is not an essential feature of science.

Falsificationism But falsificationists saw science as a process of conjecturing which may come from intuition or from imagination. Here, the facts wont tell the scientist which of the scientific conjectures are true, but the facts will tell scientist which scientific conjectures are false.

FalsificationismThus, theory cannot be conclusively verified by particular observations, but it may be conclusively falsified or refuted by particular observations.

A logical point of falsificationalismSome theories can be shown to be false by an appeal to the results of observation and experiment. Although it is assumed that true observational statements are available, it is never possible to arrive at universal laws and theories by logical deductions.

A logical point of falsificationalismHowever, it is possible to perform logical deductions starting from singular observation statements as premises, to arrive at the falsity of universal laws and theories by logical deduction.

A logical point of falsificationalism example a cat which was not black was observed at place x at time t, then it logically follows from this that all cats are black is false, that is the argument is logically valid deduction Premise : a cat, which was not black, was at place x at time tConclusion : not all cats are black Here, if the premise is asserted and the conclusion denied, a contradiction is involved.

Other examples of trivial logical point of falsificationismPremise : A 10 kg weight, and 1 kg weight in free fall move downwards at roughly the same speedConclusion : then bodies fall at speeds proportional to their weight is false.

Premise : A ray of light passing close to the sun is deflected in a curved pathConclusion : it is not the case that light necessarily travels in straight lines.

Thus, the falsity of universal statements can be deduced from suitable single statements.

Falsifiability as a criterion for theories This school of thought sees science as a set of hypotheses that are tentatively proposed, aimed at describing the behaviour of some aspect of the world or universe. But, not any hypothesis will do. To fulfill condition that any hypothesis must satisfy if it is granted the status of scientific law or theory, an hypothesis must be falsifiable. For example, 1. it never rains on Sundays this assertion is falsifiable and false because it can be falsified by observing rain to fall on a Sunday 2. all substances expand when heated this assertion is falsifiable and false because it can be falsified by an observation that some substance, x, did not expand when heated at time t (eg: water near its freezing point). Thus, this conclusively refutes or falsifies the scientific conjecture that all substances expand when heated.

Example of assertion that is falsifiable3. heavy object such as brick when released near the surface of the earth fall straight downward if not impeded this assertion may be true, but it is falsifiable because the next brick to be released will fall upwards. Here, no logical contradiction is involved, the brick fell upwards when released.4. When a ray light is reflected from a plane mirror, the angle of incidence is equal to the angle of reflection this assertion may be true, but it is falsifiable because a ray of light incident on a mirror at some oblique angle could conceivably be reflected in a direction perpendicular to the mirror. This will never happen if the law of reflection happens to be true, but no logical contradiction would be involved if it did.

Example of assertion that is falsifiable3. heavy object such as brick when released near the surface of the earth fall straight downward if not impeded this assertion may be true, but it is falsifiable because the next brick to be released will fall upwards. Here, no logical contradiction is involved, the brick fell upwards when released.4. When a ray light is reflected from a plane mirror, the angle of incidence is equal to the angle of reflection this assertion may be true, but it is falsifiable because a ray of light incident on a mirror at some oblique angle could conceivably be reflected in a direction perpendicular to the mirror. This will never happen if the law of reflection happens to be true, but no logical contradiction would be involved if it did.

The hypothetico-deductive view of science (Popperism)this view known as falsificationism which states that science does not start with stark observation, but with problems.to solve the problem, hypotheses are falsified and then tested.deductions are made which are then tested again in an attempt to disprove the hypothesis.if deductions fail, then the theory becomes more corroborated and if deductions succeed, the theory will be rejected.the falsificationist view of science as falsifying theories and replacing them with the better one.

Popperism The first view is the ultimate explanation by essences. Essentialism is part of the Galilean philosophy of science. This view is distinguished by three elements (doctrines): i. the scientist aims at findings a true theory or description of the world (especially of its regularities or laws) which also an explanation of observable facts ii. The scientist can succeed in finally establishing the truth of such theories beyond all reasonable doubts iii. The best and truly scientific theories describe the essences or the essential nature of things the realities which lie behind the appearance Popper accepts (i), thinks (ii) needs correction, for all that a scientist can do is to eliminate those theories that do not stand up to the most severe tests but he can never be sure that new tests may not lead him to modify or discard his theory. Popper disagrees (iii) that science aims at ultimate explanation an explanation which by its nature cannot be further explained and which in no need of further explanation.

Popperism The second view considers theories as instruments. The function of theory is described in the following a, b are phenomena A, B are corresponding realities behind these appearances , are descriptions or symbolic representations of these realities E are essential properties of A, B is the theory describing E From and , we can deduce p; this means we can explain with the help of our theory why leads to or is the cause of b. A representation of instrumentalism can be obtained from this schema by omitting the universe of realities ; then describes a, and directly describes b and describes nothing; it is mainly an instrument which helps us to deduce from . This is the instrumentalist view.

Popperism cont The third view is that Popper preserves the Galilean doctrine which the scientist aims at a true explanation of observable facts; and it combines this doctrine with the non-Galilean view that though this remains the aim of the scientist, but he can never know for certain whether his findings are true, although he may sometimes establish with reasonable certainty that a theory is false. Here, scientific theories are genuine conjectures highly informative guesses about the world although not verifiable (not capable of being shown to be true). They are serious attempts to discover the truth.

Conjectures Poppers examples I hold that observations are more or less indirect, and that it is doubtful whether the distinction between directly observable incidents and whatever is only indirectly leads us anywhere. I cannot but think that it is a mistake to denounce Newtonian forces (the causes of acceleration) as occult, and to try to discard them (as has been suggested) in favour of acceleration. For acceleration can not be observed any more directly than forces; and they are just dispositional: the statement that a bodys velocity is accelerated tells us that the bodys velocity in the next second from now will exceed its present velocity

Dispositional - examples all universal are dispositional. if breakable is dispositional, so is broken. red is dispositional: a thing is red if it is able to reflect a certain kind of light if it looks red in certain situation. But even looking red is dispositional. It describes the disposition of a thing to make onlookers agree that it looks red. There are degrees of dispositional character: able to conduct electricity is dispositional in a higher degree than conducting electricity now which is very highly dispositional. These degrees correspond closely to those of conjecture or hypothetical character of theories.

Popperisms View of ScienceScientific knowledge consists of theoretical conjectures whichHave been falsified or refutedHave still to be tested by attempted falsifications Have so far resisted all attempts at falsification, these conjectures are still open to possible falsification and they cannot be seen as being finally and conclusively true.The crucial feature of scientific method is actively seek to falsify and refute the conjecture or hypothesis presented to explain natural phenomena.Through excluding falsified conjectures, the truth becomes closer and closer but It does not mean to say finally and conclusively this is the truth.Thus, this school of thought emphasizes on the creative and imaginative side of the scientific process

Problems of Popperismi. The notion of falsification it is possible to falsify or refute a scientific generalisation conclusively by a single observation. This assumption indicates that direct observations of natural phenomena can be made (this assumption contradicts Popperism that observations always take place within the context of a theory they are theory dependent or theory laden), and those observations are themselves not subject to falsification (this assumption again flouts the falsification principle itself that every scientific statement must be open to falsification). For example, a metal does not expand when heated. This observation statement can never be infallibly true because they may well be falsified in the future. Theories then cannot be falsified by individual observation statements because those individual observation statements can never be conclusively true.

Problems of Popperism cont ii. The failure to account for the actual historical practice of science since falsification or refutation has not been seen as essential by scientists. Theories are often maintained by scientists, and this is ofteh the case when there is no clear alternative to the theory in question.

For example, there is evidence (prima facie) which falsifies the theory of evolution, but the explanatory value of the theory is so great and the alternatives to the theory so unthinkable, that the scientist holds on to the theory despite the apparent evidence against it.

Lakatos (1922-1974) He attempted to reformulate the problems of Popperism by distinguishing three versions of falsifiability principle. i. dogmatic falsification which claims that a simple observation can refute a scientific theory ii. Nave methodological falsificationiii. Sophisticated methodological falsification

The Route to Normal ScienceAccording to Kuhn, a scientific community cannot practice its trade without some set of accepted beliefs.Thus, normal science means research based on one or more past scientific achievements, achievements that some particular scientific community acknowledges for a time as supplying the foundation for its further practice.

The Route to Normal Science (2)These achievements called as paradigms

Paradigms Refer to each great scientific epoch which dictate in effect what is to be considered science at any particular time and what is not. Thus, the areas of scientific research that are thought to be interesting and important, the issues that are considered to be problems and those that are not, the style of scientific research, even what is considered to be scientific fact these are all dictated by the paradigms or models of science that are adopted at any one time.

The structure of scientific revolutions Kuhn challenged inductvist anf falsificationist accounts of science because he found that these traditional accounts of science do not bear comparison with historical evidence. He developed account of science as an attempt to give a theory more in keeping with the historical situation. The history of the process is seen as the dominant paradigm (the pre-history of the mature science), and the mature of science as the emergence of a specialist group or dominant group The emphasis of this theory is placed on the revolutionary character of scientific progress, where a revolution involves the abandonment of one theoretical structure and its replacement by another, incompatible one. Kuhns picture of the way a science progresses can be shown as open-ended: pre-science normal science crisis revolution new normal science new crisis The disorganised and diverse activity that precedes the formation of science eventually becomes structured and directed when a single paradigm becomes adhered to by a scientific community (dogma as the terms of acceptance).

The history of Galileo & Newton Kuhn found that Aristotles theory of motion within the context of Newtonian mechanics, at first sight seemed to be both simple-minded and false. But, if grasped the point, then Aristotle motion meant different from what it meant for Newton. Here the Aristotelian system made coherent sense. Thus, Aristotles science could not be compared directly with Newtonian science, the two systems were quite incomparable and incommensurable theoretical world The change from the Aristotelian view to the Newtonian view could not be seen in evolutionary terms (Newtonian mechanics corrected the mistakes of Aristotles physics an provided a more complete and sophisticated account), but Newtons science was a revolutionary new way of investigating the new world.

The structure of the scientific revolutions cont A paradigm is made up of the general theoretical assumptions and laws and the techniques for their application that the members of a particular scientific adopt. Workers within a paradigm (such as Newtonian mechanics, wave optics or a bulk of scientific work done, accepted by its practitioners of a system of concepts, methods and assumptions a type of instrumentation, a metaphysical speculation, a textbook) called as normal science. Normal scientists will articulate and develop the paradigm in an attempt to account for the behaviour of the real world through the results of experimentation. During this attempt, normal scientists will experience difficulties and encounter falsifications. If these difficulties get out of hand, a crisis state develops. A crisis is resolved when an entirely new paradigm emerges and attract the allegiance of more scientists until eventually the original paradigm is abandoned. The discontinuous change constitutes a scientific revolution. The new paradigm now guides new normal scientific activity until it too runs into serious trouble and new crisis followed by a new resolution results.

Kuhns normal science & revolutionary science In addition, an account of science is influenced by the social behavior of scientists (scientific communities) because he found the disagreement between social scientists (psychologists or sociologists) about the nature of legitimate scientific problems and methods, as the practitioners of natural sciences fail to evoke the controversies over fundamentals. This behaviour is more open to charges of irrationalism and subjectivism because these factors affect the substantive aspect of science. Thus, the role in scientific research which called paradigms, in attempts to discover the source of that difference between the practitioners of the natural sciences and social scientists This Kuhns organizational aspects include: normal science, revolutionary science and paradigm.