History of Psychology 2008 Lecture 5: Galileo, Aristotle, and Descartes

1. History of Psychology 2008 Lecture 5 Professor Cupchik Office: S634 Email: cupchik@utsc.utoronto.ca Office hours: Wed 1-2; Thurs 12-1 Course website: www.utsc.utoronto.ca/~cupchik TA: Michelle Hilscher Office: S142C Email: hilscher@utsc.utoronto.ca Office hours: Wed 12-2 pm Textbook: Benjafield’s History of Psychology

2. Final paper details… 1. Total of 50 marks (1/3 of final mark) Content /20 Organization /15 Style /10 Spelling & APA /5 2. Should be 20 pages double-spaced, including references and title page. 3. Explore history of change within and outside of the discipline. 4. Sources… 5. Due by midnight on Monday December 1st by emailing a regular Word Document (no docx) to hilscher@utsc.utoronto.ca. 1

3. Extra slide for last week’s lecture… • Contrast between Galileo and Aristotle. • Galileo reduced all nature to primary qualities (size, figure, number, motion). All else was subjective and secondary. • This was a change from Aristotle’s metaphysical approach to motion. Local motion is no longer a special, temporal case of the metaphysics of change. Motion is no longer a kind of development by which things realize their natural ends. This relates to the idea of teleology (or purpose). • Aristotle believed that there are different rules guiding motion in space versus motion on earth. • Galileo on the other hand, felt there is no meaning in motion, only quantity; the abstract quantity of velocity which has time and distance components. 2

4. Moving on to Descartes… -Lived a long time in Holland. -Trained in a Jesuit College. -Skeptical attitude which was a ‘fashion’ of the time due to constant disagreement among theorists. (1596-1650) After the 18th century, knowledge passes from philosophy to science which assumes only uniformity of law and neither unity of truth nor cosmic personality. Descartes was the last to make a major contribution out of a metaphysical position. The image of infinite mechanics proved ultimately to be irrelevant. Science ranges between the unity of nature and the multiplicity of phenomena. 3

5. Scientific Contributions a. He developed the principle of inertia. It paralleled with conceptions of infinity. b. Analytic geometry – wrote equations that determine a geometric form. Galileo turned time into a dimension – an abstract parameter of the state of motion which science can measure. Descartes crossed time at right angles with distance and space in depth. c. Correct laws of refraction. d. Eliminated the purposive organism. 4

6. Rational Method a. Accept as true only that which presents itself to the mind with such clarity and vividness as to remove the smallest element of doubt. b. Divide a problem into as many discriminable elements as possible. c. Work from a solution to the smallest to that of the greatest. d. …to ensure the generality of the solution. In relation to epistemology… Recognize the limits of the senses and adapt a skeptical position that all is illusion. But, even if the body is an illusion; even if all our actions and experiences are unreal, the ideas of the mind must exist or doubt itself is impossible. Reason, not matter, therefore confirms existence. 5

7. Matter vs. Mind • Qualitatively different things. Matter is res extensa (extended substance) and mind is res cogitans (thinking substance). • Descartes views of matter and mind were influenced by Vesalius (1514-1564) who founded the discipline of anatomy, as well as Harvey (1578-1657) who founded physiology and worked out the connection of the cavities of the heart with each other and with the lungs, arteries and veins. This work told physiologists how the blood must be flowing. Descartes studied anatomy and made dissections. • He developed a model of reflex action based on mechanics. He was inspired by mechanical models of the time, and was impressed with manikins in the French Royal gardens which could move, play instruments and even produce sounds as a result of water moving through tubes. 6

8. Besides mechanics, several other things inspired Descartes’ reflex action model… -Knowledge that not all movements are voluntary -Movements performed by decapitated animals. Reflex Theory: Eye  Sensory Nerve  Brain  Motor Nerve  Muscle  Action 1. Nerves were like hollow tubes 2. The brain was like a sponge… porous… The nervous system works through the actions of fluids. The fluid or animal spirit is like a gas… not quite material. When an impression is made on a sense organ, the sensory nerve works like a bell wire, it pulls open the valve to which it is attached and allows the animal’s spirits to flow down the corresponding motor nerve to the muscle. This form was the basis of all physiological psychology of the 17th and 18th centuries. 7

9. But what about the soul? The body and soul are clearly separate. 1. The body is part of the world of matter peculiar to man. Therefore, as matter it can be dealt with scientifically or mechanically. 2. The soul does not move the body. Death is not due to the absence of the soul from the body, when the bodily functions cease, the soul disappears. So Descartes removes the soul from every part of the concept of physical life. Physical life is essentially movement which depends on the muscles and these in turn depend on the nerves. The corporeal principle of movement is a kind of fire, a natural heat that resides in the heart. Like Aristotle, Descartes recognizes two levels of conscious activity (thinking/remembering and common sense/imagination/instinct). 8

10. How can the mind affect the body if it does not exist in space? As the “seat of the soul” Descartes selected the pineal gland probably because of its uniqueness. The mind makes the pineal gland bend thereby deflecting the animal spirits into a different channel. Cogito ergo sum - “I think therefore I am.” Dubito ergo sum - “I doubt therefore I am.” 9

11. The nature of ideas for Descartes: 1. The clearest ideas are those that give the most fundamental truths and they are innate in the soul - the idea of G-d, self, and axioms of mathematics. 2. The ideas of external objects come through the senses and others, like hunger or thirst, or awareness of the emotions, arise within the body and affect the mind. 3. He does suggest in some places that memories are connected with traces left in the brain. In one place he describes the animal spirits are running through the pores of the brain until they find a specific memory desired by the mind. Descartes does separate man completely from the animal world. They are reduced to mere machines but later he admits that animals may have sensations. 10

12. In sum, reason is only proper to man but humans and animals overlap with the reflex theory. The human body is an animal organism associated with a rational soul. Animals are bodies only. The idea that, as a body, man belongs to the animal kingdom, while as mind he belongs to another realm led to the study of man being divided into (1) physiology and (2) psychology. 11

13. Final Summation: 1. He revolted against the ancients. 2. He revised the concept of the human mind as partly free and rational and partly mechanical and automatic. 3. His is the father of dualistic thinking (separates mind and body) and of the reflex arc. 4. He believed in a free unsubstantial soul and a mechanically operated body. 5. He applied principles of physics to the body… mechanics of the body. 6. He also anticipated projection theory… changes which occur in the motion of the animal spirits may cause them to open certain pores of the brain rather than others. 7. While he broke with ancient philosophy, he still adhered to a deductive method - Rationalist. 12

14. The British Enlightenment • We find in all historical eras that psychological theories match models in the physical sciences. What is the Newtonian model, and how has it been manifested in psychology? • Sir Isaac Newton (1643-1727): • English physicist, mathematician, astronomer, alchemist and natural philosopher. • Wrote the Philosophiae Naturalis Principia Mathematica where he described universal gravitation and the three laws of motion, laying the groundwork for classical mechanics. -By deriving Kepler’s laws of planetary motion from this system, he was the first to show that the motion of objects on Earth and of celestial bodies are governed by the same set of natural laws. The unifying and deterministic power of his laws was integral to the scientific revolution and the advancement of heliocentrism. He also was a devout Christian, studied the Bible daily, and wrote more on religion than on natural science. 13

15. Note on dates: During Newton’s lifetime, two calendars were in use in Europe: the ‘Julian’ or ‘Old Style’ in Britain and parts of Eastern Europe, and the more accurate ‘Gregorian’ or ‘New Style’ elsewhere. The difference between them lay in their attitude to leap years. At Newton’s birth, Gregorian dates were ten days ahead of Julian dates: thus Newton was born on Christmas day 1642 by the Julian calendar but on January 1643 by the Gregorian. Among other scientific discoveries, Newton realized that the spectrum of colors observed when white light passes through a prism is inherent in the white light and not added by the prism (as Roger Bacon had claimed in the 13th century), and notably argued that light is composed of particles. 14

16. He also developed a law of cooling, describing the rate of cooling objects when exposed to air. He enunciated the principles of conservation of momentum and angular momentum. Finally, he studied the speed of sound in air, and voiced a theory of the origin of stars. Despite this renown in mainstream science, Newton spent much of his time working on alchemy rather than physics, writing considerably more papers on the former than the latter. Newton played a major role in the development of calculus, famously sharing credit with Gottfried Leibniz. He also made contributions to other areas of mathematics, for example the generalized binomial theorem. The mathematician and mathematical physicist Joseph Louis Lagrange (1736-1813), often said that Newton was the greatest genius that ever existed, and once added “and the most fortunate, for we cannot find more than once a system of the world to establish.” 15

17. Newton offered a single theory that accounted, with mathematical precision, for all the phenomena of interest to physics at that time including planetary motion and ocean tides. His was a materialistic theory. Comparison of Greek and Newtonian materialism: 1. Greeks: Matter included minute particles of certain shapes. Newton: Refined this idea to infinitesimal mathematical points. So he dealt with ideal constructions and not physical entities. 2. Greeks: It had been assumed that motion could only be transmitted by physical contact. Newton: Stressed forces of attraction and repulsion. 16

18. Galileo had also emphasized the all-pervasive presence of motion in the world. These principles exerted a strong influence on the study of the process whereby we attain knowledge: cognition. Can we attain true knowledge? * The Greeks felt that knowledge could be obtained through Rationalism, logical thought. * The Medieval Christians stressed revelation. * The new science questioned the authority of reason and revelation. The relativistic misgivings of Protagoras were revived. How do we obtain knowledge about the world? How are we deceived? These questions are related to the problems of sense-perception, memory, imagination and thinking. 17

19. Today we are going to talk about empiricism, but what does it mean? Two meanings. We distinguish between the empirical approach and empirical theory. Empirical approach: Demand a scrutiny of the facts of experience before any theory is propounded. This reveals an interest in the conscious experiences which can be directly inspected and analyzed. Empirical theory: The theory that all contents of the mind are derived from experience. This reflects an interest in the cumulative results of past experience. The empiricist theory is a theory of knowledge - epistemological. It challenged the authority of revealed religion and affirmed a faith in natural law. 18

20. Experience not revelation is the source of knowledge. But they were not anti-religious. So they sought natural laws of knowing that fit with the natural laws of the physical sciences. Two big questions: 1. Are there at birth ideas that are not furnished through experience? This is a reference to the innate ideas of Plato and Descartes. 2. Can we distinguish between ideas that correctly represent the “real” world from those generated by the perceiver? The empiricist and associationist traditionshave had the greatest impact on modern experimental psychology and made perception the primary problem in psychology. 19

21. Thomas Hobbes (1588-1679) Thomas Hobbes was an English philosopher, whose famous 1651 book Leviathan set the agenda for nearly all subsequent Western political philosophy. Although Hobbes is today best remembered for his work on political philosophy, he contributed to a diverse array of fields, including history, geometry, ethics, general philosophy and what would now be called political science. Additionally, Hobbes’s account of human nature as self-interested cooperation has proved to be an enduring theory in the field of philosophical anthropology. He was a contemporary of Descartes, a political philosopher and author of Leviathan. He addressed the issue of what was meant by “sense” knowledge. He referred the contents of the mind to sense-experience thereby doing away with the notion of innate ideas emphasized by Descartes. 20

22. Association depended on the coherence of past ideas. He was impressed, after meeting Galileo, with the omnipresence of motion. If all is motion in the world outside then perhaps this can explain the mind. He analyzed memory and imagination processes which are described as “decaying senses”. This explains why we do not always have an awareness between its origins in the sense and reappearance in memory. He assumes that the fainter elements of “decaying sense” are obscured by the brighter sensation, as the stars are dimmed by the brightness of the sun. Laws of Association: Recognized the importance of connections between ideas and the original sensation in accounting for their reappearance. He distinguished between two trains of thought: 1. Guided by the intent of the thinker 2. Unguided and without design 21

23. Social Philosophy: What is the basis for cooperation? Man was born in conditions of mutual warfare and enlightened selfishness alone brought them into agreement with their fellows. John Locke (1632 - 1704) Locke was an influential English philosopher. In epistemology, he has often been classified as a British Empiricist, along with David Hume and George Berkeley. He is equally important as a social contract theorist, as he developed an alternative to the Hobbesian state of nature and argued a government could only be legitimate if it received the consent of the governed through a social contract and protected the natural rights of life, liberty, and estate. If such consent was not given, argued Locke, citizens had a right of rebellion. Locke is one of the few major philosophers who became a minister of government. 22

24. Locke’s ideas had an enormous influence on the development of political philosophy, and he is widely regarded as one of the most influential Enlightenment thinkers and contributors to liberal theory. His writings, along with those of the writings of many Scottish Enlightenment thinkers, influenced the American revolutionaries as reflected in the American Declaration of Independence. He held fundamental ideas about the importance of liberty and tolerance that were formed early in this life. His basic concern was about the nature of human understanding. Basic Principle: The mind can be broken down into ideas. If we divide what we know consciously at any given time into components, we find that we have ideas. This opposes the doctrine of innate ideas: Descartes’s idea of g-d, self, time, and space as innate. 23

25. * Ideas are the units of mind - the unit of mental contents - analogous to material elements. (e.g., whiteness, hardness, thinking, motion, man) * Ideas are logical constructs or concepts or “meanings” or “items of knowledge”. * They are simple or complex and bound by empirically determinable laws. * There are no ideas in the mind that were not derived from sense perception. * Learning principles will explain all of what we know and are. 24

26. Ideas come from: 1. Sensory Experience (tabula rasa) - Sensible qualities are conveyed into the mind from external bodies and these produce perceptions. 2. Reflection on experience - How does the mind attain knowledge of its own operations? - Reflection is an “internal sense”. It is the source of ideas about ideas and the manner of their occurrence. - It is a reaction of the mind upon the original experience. Locke introduced the concept of connections or associations among ideas. These associations are complex and can be simultaneous or successive. Custom is the basis for the establishing of associations. This anticipates the Law of Frequency. 25

27. But how dependable is sense perception? (e.g., Does the naked eye tell the truth when the microscope gives a different picture?) The physicists were reducing the world in terms of space, time, mass, and motion. But where do we find in the world of the physicist the colour, sound and smells of sensory experience? 26

28. Are sensory qualities in the realm of illusion? Locke resolved the problem in this way. He believed that the world exists independently of our knowing it and that it is faithfully represented in our experience of it: representative realism. But how much of conscious experience comes from the real world and how much from the perceiver? He resolved this with the distinction between primary and secondary qualities. Primary qualities are inherent in nature - extension of space, enduring of time, substantiality, motion, or rest. - These qualities are inseparable from the object regardless of what happens to it. - These ideas are like the properties of the objects that produce them. - These properties are perceived “directly as such”. 27

29. Secondary qualities are “sensory qualities” such as colours, sounds and smells which vary with the conditions of observation and the state of mind of the perceiver. They are powers possessed by an object for producing ideas which do not exist within the object in the form in which they are perceived. These ideas do not resemble the properties of the object at all but are produced indirectly by the action of other properties. For example: Vibration frequency is a secondary quality because it arouses the experience of musical pitch which it does not resemble at all. So there is not an exact correspondence between the two. 28

30. So the contents of mind can be observed, analyzed and explained in accordance with natural principles. This would appear to be a kind of passive process. Ideas are fixed by (1) attention and (2) by the pleasure or pain that are connected with them at the time of the original experience. They fade with time but, if repeated sufficiently often, need never be forgotten. The mind may even appear active in recall as if searching for a memory. 29