History of Science 2220 Lecture Notes - Lecture 9: Scientific Method, Falsifiability, Cell Division
2 May 2018
School
Department
Course
Professor
Physiology Lecture Part 3
Overview
1. Positivism and Bernard
2. Mechanism and Chemistry
3. Vitalism and Cell Biology
Positivism and Bernard (Duffin, 51 and 54)
- Peer Observation, measurement, and experimentation (rather than theory-construction and
speculation) yield truth
- “The facts speak for themselves”
o always want to get the facts: just true because that’s the way it is
- No evidence, no credibility
- Resist speculation on causes and purposes
- Goal to use scientific method to figure out what is actually going on instead of the mind’s
interpretation
- Positivism has wholly dominated medicine
o Evidence-based medicine: want to prove how well your medicine works
o Deemed wrong or useless if you cannot prove your scientific claims with facts
o Avoid subjectivity and speculation, and see what is the case
- Knowledge via Observation (positivism)
o Truth is the goal of observation
o 5 senses (sight, hearing, touch, taste and smell)
o tools (observation and calculation aids)
▪ assistive devices that allow you to detect, measure and identify a specific
cause (a definitive lesion)
o Democratic
▪ Open to everyone to investigate as long as you have solid evidence
▪ Don’t require a title in the church instead need the right skills and training
▪ The more people using reason results in more knowledge being generated:
a basic knowledge of science has a possibility to discover great things
▪ Olitically enlightened for people to know the truth
▪ Openness to enquiry that can’t be restricted without people discovering their
own truth
o Patterns in nature
▪ Looking for laws in nature
▪ Finding patterns fixed in nature: God just cannot change the law of gravity
o Testable (falsifiable)
▪ Can show that it is definitely wrong
▪ Open to challenge by the facts
** contrast with religion and look at the differences**
find more resources at oneclass.com
find more resources at oneclass.com
blames individuals for their failures and illnesses (a dogmatic approach!!)
Claude Bernard’s Introduction to the Study of Experimental Medicine (1865) is a classic in the
science of physiology
- A physiologist using the scientific method
- Animal experimentation in which it’s a key part of physiology
o Main reason because you can’t experiment on humans
- Experimentation differs from passive observation:
o Need to do something to that organism and then tracking the results
▪ Localization of function (ex. Parkinson’s/ tremors effect on the brain)
▪ Lesion-formation ( do something to induce, cause damage to the part of the
brain )
▪ Observation of effect (deterministic cause and effect relationship)
• Discover a physiological truth that allows you to understand the
normal function
- By damaging the normal state of the organism, you discover how it is supposed to work
- Bernard thought the only way to understand the normal function is by using animals
Known for discovering how things work in the body
• Credited with discovery of:
1. vasomotor nerves (which control blood vessel dilation)
2. effect of poisons on muscles (e.g., curare as muscle relaxant)
3. function of pancreatic juices (digestion of fats)
4. the internal secretions in the liver (glycogen formation)
5. “Steady state”/ “internal milieu”
Main Entry: ho·meo·sta·sis (inner environment = ‘internal milieu” ):
• the maintenance of relatively stable internal physiological conditions (as body
temperature or the pH –acidity– of blood) in higher animals under fluctuating
environmental conditions;
(from Medline Plus)
- Named as such by Walter Bradley Cannon (American)
- Homeostasis is a dynamic equilibrium
o Looks at when the body can no longer maintain the equilibrium and as a result dies
- Combination of body systems: a unity and shared goal: the survival of the organism
o = boundary between self and other (inside and outside, here and there)
o plays into vitalism: body has its own living dynamic agency that isn’t about rational
thought but rather your bodies’ will to live and survival
▪ a unity of purpose: drive/will to live
find more resources at oneclass.com
find more resources at oneclass.com
ex. with the brain we don’t think about these things
Mechanism and Chemistry (Duffin, 49)
- Simple experiment: shows chemistry and discovering the normal function by destruction/
damage as a means to understand normalcy
- John Mayow’s mouse and candle (1674)
o Tries to understand the role of air and its effect on living organism
- A mouse in a sealed jar consumes as much air as a candle burning in the same jar (both
illustrate process of oxidization/combustion)
o Tries to see how long and how much air is consumed before the mouse dies
o Approx. after 1/5 of air is consumed, the mouse will die/ the candle will burn out
▪ What is the common function that they both share? 20%
• Mechanistic: shows that living things functionally behave in the
same way as non-living things
• Chemically similar!
Air is composed of:
• Oxygen – 21% (approx. 1/5)
• Nitrogen – 78%
• Argon – 1%
• Oxygen (O2) unlocks energy in chemical reactions
• Interacting in way that produces energy: can be wood, carbohydrates in the
body
• Same kind of chemical reaction that burning woods or metal rusts and
breaking down sugars all have the same chemical function (oxygen a key
factor)
• Carbon dioxide (CO2) is a byproduct of energy production
Mechanics: Using chemistry and physics to understand what living and non-living things have in
common.
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Overview: positivism and bernard, mechanism and chemistry, vitalism and cell biology. Peer observation, measurement, and experimentation (rather than theory-construction and speculation) yield truth. The facts speak for themselves : always want to get the facts: just true because that"s the way it is. Goal to use scientific method to figure out what is actually going on instead of the mind"s interpretation. ** contrast with religion and look at the differences** blames individuals for their failures and illnesses (a dogmatic approach!!) Claude bernard"s introduction to the study of experimental medicine (1865) is a classic in the science of physiology. Animal experimentation in which it"s a key part of physiology: main reason because you can"t experiment on humans. Experimentation differs from passive observation: need to do something to that organism and then tracking the results, localization of function (ex. By damaging the normal state of the organism, you discover how it is supposed to work.
