History of Science 2220 Lecture Notes - Lecture 8: Teleology, Humorism, Vitalism
2 May 2018
School
Department
Course
Professor
Physiology Part 2
Overview
1. Teleology and vitalism
2. Galen
3. Harvey
4. Descartes
5. Blood
Teleology + Vitalism (Duffin, 42)
- To be alive = to have a telos
- Telos = function/purpose/aim
o Things designed to achieve
- Ultimate purpose – “why?” (Duffin, 64)
o Science can explain what it means to be alive but it cannot explain why they are living
things and their point
▪ The goal of any living organism is to perpetuate another species
- Natural laws guide the parts and overall function of the organism
- Acorn is a seed that produces an oak tree (potential for what can become is its purpose)
o The goal is to turn into a tree
- There is a harmony in all nature
o Has its purpose for every part of our body that has a function
▪ We should use the parts knowing that they’re fully able to perform a function
Strong influence of Aristotle’s theory of causes here:
- The final cause: “the end, that for the sake of which a thing is done”, e.g., health is the end of
walking, losing weight, purging, drugs, and surgical tools.” (Stanford Encyclopedia of
Philosophy)
▪ Philosophical approach is speculative- typically, a bad way to do physiology
(thinks before it looks)
• Prejudicing what you observe by thinking about it too much
Galen
- According to Galen, the body functions according to final causality:
o there is a purpose for everything, as determined by nature
▪ sense that the body knows what it needs, can be mistakenly used for purpose
of the body
▪ losing something can cause great trauma or problems
o Organs has specific functions: attractive, retentive, alterative, repulsive or eliminative
(Duffin, 45)
▪ Either repels things or attracts things
o Everything in the body has a purpose
- Galen sought to combine theory of (4) humors with the theory of spirits
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o These spirits aren’t religious ideas (Aristotle again!)
▪ Becomes a spiritual idea later on
▪ Explains a certain kind of energy, a force (not an immortal spirit)
o They are key components of blood distribution (Duffin, 43-4)
▪ Associated with life
- Blood is the vehicle for transporting these spirits
- Blood is “animated”
- Blood is life (Duffin, 195)
o Thought blood could go through the walls of the heart
1. Natural spirits (pneuma physicon) and blood from food in the liver
a. Not just in food but stomach is the first gateway in which food passes through to the
liver. There in the liver, natural spirits are activated
b. Lowest levels of spirit
c. Creates blood
d. Some of that blood goes to the heart
2. Vital spirits (pneuma zoticon) enter through the lung and mix with blood in the heart
a. blood moves from the right to left ventricle through the septum
i. (vital signs related to the heart)
b. blood in liver goes to the heart, mixes with air and turns into vital spirits
i. blood has to move through one side to the other to allow the air and blood to
mix
c. Dispersed via veins and arteries once its mixed to the rest of the body
3. Animal spirits (pneuma psychicon) added in the brain and dispersed via nerves
(Duffin, 43-44)
a. About movement and the ability to move: having awareness of your environment
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-shows the pathway, each level has an exit
-top: nerves & brains
-circle is liver
-certain foods emit energy which can result in different types of humors
-dynamic and accounts for difference in function but not accurate
-tries to categorize function !!!
- Unlike Hippocrates, Galen did experiments to support his interpretation of the body
- Yet, Galen’s experimental approach was grounded in excessive speculation
o Unable to observe properly: no microscopes and doesn’t understand chemistry
o Makes things up to fill in the void
o Fallibility not appreciated because he was seen as a dogmatic and systematic
thinker because his views could not be challenged at all
- Too much philosophy! (Duffin, 45)
Harvey and the Heart (1578-1675)
- William Harvey proved through experimentation that blood circulated through the heart
o Highlights experimental proof and how it helped demonstrate how the heart works
o Shows the body as a machine: the heart represents a pump
o How do things work, how are they connected, can it be fixed if broken down
- His findings were published in 1628 in De motu cordu et sanguinis (On the movement of the
heart and blood)
o Science works on the facts as observed
- He rejected Galen’s view of digestion-circulation-spirits
o Harvey’s views dominant for a while humoral theory still lingers
o Breached the defense in humoral theory
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Overview: teleology and vitalism, galen, harvey, descartes, blood. To be alive = to have a telos. Telos = function/purpose/aim: things designed to achieve. Natural laws guide the parts and overall function of the organism. Acorn is a seed that produces an oak tree (potential for what can become is its purpose: the goal is to turn into a tree. There is a harmony in all nature: has its purpose for every part of our body that has a function, we should use the parts knowing that they"re fully able to perform a function. Strong influence of aristotle"s theory of causes here: The final cause: the end, that for the sake of which a thing is done , e. g. , health is the end of walking, losing weight, purging, drugs, and surgical tools. (stanford encyclopedia of. Philosophy: philosophical approach is speculative- typically, a bad way to do physiology (thinks before it looks, prejudicing what you observe by thinking about it too much.
