PS2080 - Lecture notes 1 PDF

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Lecturer: Deirdre Birtles...

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Lecture 1 – Introduction to Philosophy of Science Lecture Outline - Scientific Revolution - Emergence of Psychology - What is Science? - Is Psychology a Science? o The discussion of three critical insights that came about during the scientific revolution as well as some of the key figures that were involved in it. o Furthermore this will focus on what definition characteristics science includes, for example what separates it from pseudo-science or religion, as well as why psychology can be considered a science Scientific Revolution There are three key elements that form the core of the scientific revolution: 1. Geocentrism to heliocentrism a. Geocentric model of the unaversive was proposed by Aristotle, and essentially it states that the earth was at the center of the universe b. The heliocentric model is accepted today and it states that the sun is at the center of the solar system. This was initially proposed by Copernicus and later supported by Galileo 2. Earthly matter could be conceptualized as machines. a. This is based on Descartes philosophy of man and its mechanistic view of the world where everything in the universe except for the human soul was a perfectly designed machine. b. This means that it could be studied scientifically 3. Mathematical equations could describe movements on earth and in the universe. a. This refers to Newton’s laws of physics, solving the problem of why planets but the sun and moon orbit. b. Through this there was an understand that science does uncover mechanisms that underly in the universe; and suggests that the scientific knowledge could be described or summarized using mathematical rules.

Geocentrism and Heliocentrism This dates to the 16th century (15000s) and is based on the growing interest in astronomy. This was due to the Julian calendar beginning to show flaws, specifically its underestimation of the length of the year by a total of 11 minutes. This meant that every 134 years there would be 11 days missing from the calendar. Due to this flaw, a lot of astronomic observations were done by many individuals including Copernicus; later replacing the Julian calendar with the Gregorian calendar.

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The Geocentric Model This was considered as the most popular theory of the universe until the 16th century. This model was described by Aristotle and later elaborated by Ptolemy. It essentially placed the Earth in the middle of the universe, with the moon and the Sun rotating around it. To add, the model also included 5 main elements that made up the universe: § Air § Water § Fire § Earth § Aether Ptolemy, a Greek mathematician and astronomer, identified a problem in the movement of the stars. He saw that whenever looking at the stars on successive nights they have moved east in comparison to the previous night. o To fix this he introduced the notion of epicycles: § These are small cycles made the stars, in addition to their main orbit around the Earth. The Heliocentric Model This was first published by Copernicus; however other authors had previously introduced the notion. o This model states that the Sun is at the center of the universe and that it is followed by: Mercury, Venus, the Earth (orbited around by the Moon), Mars, Jupiter, Saturn and the sphere of immobile stars. o Other features include: § One turn around the Sun for the Earth takes approximately 1 year (365 days) § The Earth spins around its own axis in a day (24h) Copernicus did not publish this model straight away for two main reasons: first he did not think that the Catholic Church would have approved of this model, as well as he did not feel like he had enough evidence to justify the model. This model was later developed by Galileo (1609) through the use of his telescope that magnified the sky up to 9x. o Through this he saw that there were many more stars that what was seen by the naked eye, as well as the Moon’s surface being rough. He also noticed that Jupiter has four moons and that the sizes of Mars and Venus change. Based on this evidence he began to argue that Copernicus’ model was much more likely that Ptolemy’s model.

The Catholic church did not appreciate his opinions and gave him a warning to stop supporting Copernicus’ model. This was done up to 1632, when he published a book showing support to this theory. The Vatican summoned him and placed him on house arrest for life. Essentially, the Church was again the heliocentric model and tried to do everything to stop its popularity. However, as more evidence was produced, the model began to seem much more convincing as well as verifiable by others; rapidly coming to dominate astronomy despite the Vatican’s resistance. -

Mechanization of the World View This idea is linked with Descartes, and his attempt to separate the realms of science and religion. Essentially, he sought a logical approach to understanding the world. Dualism – the mind/soul is immaterial and independent of the body. Mechanistic View – the universe and all it contains, including the human body, is one big, sophisticated machine. He hypothesized that part of the brain, the pineal gland, served as a passageway between the body and the soul. This is wrong, but his teachings have had a large impact on modern psychology: - Theory of cognition (I think therefore I am) - Autonomic reflexes - Self-awareness - Attention - Self-observations – introspection The formulation of the first laws of physics Newton is the main key figure in this key element of the scientific revolution. He formulated the first laws of physics, specifically those that govern the motions of planets and universal gravitation. - To do so, he analyzed Galileo’s work, specifically the cannonball idea. o Galileo stated that a cannonball’s path was a parabola, and the stronger the forces when being shot to further it would land. o This is a relationship that can be described mathematically. - Newton through insight, stated that if you place the cannonball on a mountain and shoot it with enough force, it will not fall and touch the earth, but rather it would circle around it. - From this initial insight, he stated that objects are therefore attracted to each other. From these two insights, he published a book called the Principia Mathematica, in which all the movements presented in the Copernican universe were described based on three mathematical laws and the postulation of a gravitational force. Through this book, he showed that science could uncover the mechanisms underlying reality and aided in the advancement of science. Other Factors Other factors that influenced the scientific revolution: - Demographic change o 14th century à population halved due to the Great Famine, the Hundred Years War and the Black Plague o 15th century à the feudal system came to an end, introducing, in majority of larger cities, a democratic regime

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o Emergence of merchants that formed link between the hand workers and the intellectual elites. § This aided because artisans made numerous mechanical discoveries but did not have the skills to systemize them, while scholars had the skills but not the means. Religious crisis o There was an absence of repressive religion or authority. o For example Galileo’s book, although banished by the Roman Catholic church was still read by places that did not follow the Church. o Christian religion also lead the scientific revolution without knowing it. This is due to the large distinction between God and science and the impossibility of the two being merged together. New inventions o Inventions of mechanical things such as clocks and compasses meant that you could develop precise scientific instruments. Universities and patronage o These areas gave a place for natural philosophers to study Enrichment forms other civilizations o Other civilizations such as the Greek and the Arab aided massively in the scientific revolution in Europe. They had been working on similar problems and thus aided in the solving of them. Investigating smaller issues. o There was also an acceptance in understanding that there was no need to necessarily investigate the big questions. Investigation of the smaller issues would have still lead to an understanding of the world.

The Scientific Method – Francis Bacon He was the one that moved from the focus on reasoning of the traditional approach (Aristotle, Plato, Descartes etc) to making the scientific method explicit. He developed the idea that science can flourish through a combination of both observations (perception) and reasoning and understanding. He also placed large emphasis on empiricism, which is conducting experiments to test claims, as well as include standardizations of methods to allow for others to replicate them. - It can be said that the adoption of Bacon’s research method was one of the reasons why science became so successful in the 17th century. Those who have handled science have been either men of experiment or men of dogmas. The men of experiment are like the ant, they only collect and use; the reasoners resemble spiders, who make cobwebs out of their own substances. But the bee takes a middle course: it gathers its material from the flowers of the garden and of the field, but transforms and digests it by a power of its own”

Emergence of Psychology - Age of Enlightenment This happened in the 18th and beginning of the 19th century. - A large importance was placed on science for gathering knowledge and for organizing society - The industrial Revolution

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French Revolution American War of Independence More time for education, better hygiene, health and communication

Philosophy integrate psychology as part of the metaphysics à 16th century (1700s) Psychology became the 4th part of metaphysics, being described as the study of the human soul. 1. Study of the universe (‘ontology’) 2. Study of God (‘natural theology’) 3. Study of the basis of theoretical knowledge (‘universal science’) 4. Study of the human soul (‘psychology’) Wolff (1679-1754) was one of the first figures to gain the development of psychology as a science. He published a book called ‘Psychologia Empirica’. - He stated that psychology was built on introspection, thus the inclusion of both reason and empirical observation. The dominance of the 4th branch of philosophy/metaphysics (psychology) began to be drawn towards the thriving natural sciences On the other hand, Kant (1724-1804) stated that psychology was not a science. - This emergence of negativity rose due to the influence that psychology was beginning to have on the population, and thus Kant (a philosopher) suggested that it couldn’t be a science and gave evidence for it. - For science you need to have a rational analysis that could be written in mathematical laws, and because psychology cannot always be explained with math it cannot be considered as a science. - Even though he did not believe it was a science he did carry out a lot of work based on psychology, although he called it anthropology: § Self-consciousness § Emotions § Role of pleasure and pain Positivism (1800s) This is a movement that was constructed following the increasing prevalence of the scientific approach. This states that true knowledge can only be obtained via the scientific method, and anything else was inferior knowledge including religion and philosophy. During this time a rebranding of names appeared as well: - Natural philosophy was rebranded to natural science - Natural philosopher was now called a scientist Early scientific studies of psychology (1800s) There was quite an interest in the human perception, and this started to develop a specific area of psychology called psychophysics, with individuals such as Weber and Fechner present in the workings of this area. à Weber conducted studies where he asked participants to hold two weights, in either hand, and try to sense a difference between the two weights. Through these studies he developed something called the limits of difference. à Fechner wrote a law connecting this sensation of magnitude to stimulus intensity. This aided in the establishment of psychophysics. There was a high interest in mental chronometry (also called mental calculations). This was presented by Donders (1868) in a study conducted as specified. He

asked individuals to listen to a sound and then repeat them. He measured their reaction times, so when he asked the participant to repeat the sound key. - Time taken to repeat “ki” = 197 ms - Time taken to repeat “ki” when set of possible stimuli increased to 5 = 243 ms - Time take to repeat any of 5 stimuli (e.g., “ki”, “ke”...etc) = 285 ms Development of statistics (1800s to early 1900s) Statistics were developed, and after the development became a crucial part of psychology. There is a major difference between physics and psychology, as the processes in physics, following mathematical calculations usually yield the same outcome every time they are repeated. Differently, psychology does not do so; thus there was the need to include measures that aided in the analysis of the different data presented. - Need for many observations, e.g., “While nothing is more uncertain than the duration of a single life, nothing is more certain than the average duration of a thousand lives” (Elizur Wright, 1804-1885) Theory of Evolution Charles Darwin needs to be considered whenever discussing the birth of psychology. He discovered how life in the universe happened and its constant change and adaptation to changing circumstances. Two of his biggest contributions were: § Natural Selection à part of the evolutionary theory where populations result in the continuation and multiplication pf certain genetic features that thrive in the environment over others that do not thrive. § Survival of the Fittest à this described how natural selection worked. What is Science? Commonsense views of science 1. Factors are given to careful and objective observers via the senses a. This is false as perceptual observation can be ambiguous, for example the Muller-Lyer Illusion and the Ponzo Illusion b. Perception requires interpretation and a theory may change the perception of the facts. Finally, a theory helps us focus on important facts. c. Scientific theories are full of non-observable facts d. Non-observable facts may become observable 2. Facts are prior to and independent of theory a. Search for facts needs to be guided by knowledge b. Without a preceding theory, we don’t know what to look for and where c. Experts perceive differently to novices 3. Facts constitute a firm and reliable foundation to scientific knowledge a. The strongest possible claim would be that the theory can be logically derived from the fact that is given i. Inductive Reasoning does not follow this idea b. In science there is/should always be room for doubt

c. Just because something is observed to happen over and over again, only means that it probably will happen again the next time, but this is not proof that it will for certain. d. No proof of anything Is Psychology a Science? There are six main criticisms that argue that psychology is not a science 1. Psychology is merely common sense a. ~ 2. Psychology does not use the scientific method a. Two crucial characteristics of science i. Willingness to root out errors in one’s belief system ii. Implementation of procedural safeguards against confirmation bias b. Psychology uses a series of designs to overcome these ‘limitations’ i. Randomized control group ii. Double-blind designs iii. Placebo control groups iv. Sophisticated statistical techniques 3. Psychology cannot yield meaningful generalisations because everyone is unique. a. Example of generalization based on research question: Why does an Alcoholics Anonymous self-help program not help everyone? i. “Each member of an A.A. group is distinct. Each group is distinct. Each moment is distinct. There is simply no way for social scientists to reduce this kind of complexity into equations and formula [sic] that can be replicated one place after another” (Brooks, 2010; para. 8). ii. But...individual differences may not undermine effectiveness of treatment for the majority or be particularly relevant to underlying mechanisms of the treatment (Hill, 1962). 4. Psychology does not yield repeatable results a. Study by Hedges (1987) i. Compare empirical cumulativeness of psychology and particle physics ii. Both sciences use similar statistical methods iii. Reviews of both sciences suggest inconsistencies – statistically significant heterogeneity in ~ 50% of reviews b. Caution: only reviews of one particular physics research domain was used c. One viable criticism à the ability to generate successful predictions due to number of causal variables 5. Psychology cannot make precise predictions a. Psychology relies on probabilities to make predictions b. Associations are often context dependent i. e.g. Relation between divorce and negative outcomes in children, widely varying estimates ii. Conditional on variables such as severity of conflict, psychopathology in parents, emotional resilience of child

c. Psychology relies on probabilities to make predictions i. e.g. Relation between divorce and negative outcomes in children, widely varying estimates from 15% to 25% d. Associations are often context dependent i. Conditional on variables such as severity of conflict, psychopathology in parents, emotional resilience of child 6. Psychology is not useful to society a.

Summary The scientific revolution (1473-1860) - The realisation that the Earth did not form the centre of universe o Copernicus & Galilei – heliocentric model - Many things on Earth can be understood as machines o Descartes – mechanistic view & dualism - Many movements on Earth/Universe can be described with mathematical equations - Newton – Law of physics Scientific method - Bacon – interaction theory and observations, falsifications & replications - Comte - Positivism The emergence of Psychology - Wolff, Kant, Darwin - Establishment of Psychophysics - Development of statistics Characteristics of science - Use of scientific method o Falsification, replication, continuous improvement, transparency Is psychology a science? - Yes...