Plutarch, On Nature
"Sentiments concerning nature with which philosophers were delighted"
An overview of Natural Philosophy
http://ebooks.adelaide.edu.au/p/plutarch/nature/
In this document, Plutarch gives an excellent overview an summary about the theories of various Greek philosophers concerning Natural Philosophy. Books 1, 2 and 4 are probably the best for discussions.
"Natural Philosophy" is the old term for what we now call "Science", and was still the more common term at least as late as Newton, who wrote "Principia mathematica philosophiae naturalis" (mathimatical principles of natural philosophy). Webster's Ninth New Collegiate Dictionary dates the origin of the word "scientist" to 1834.
Notes on Book 1
3 philosophical branches: natural, moral, logical. natural philosophies = science, moral philosophy = ethics, logical philosophy = dialectic and mathematics. (Socrates was moral philosopher, and explicitly said he had no interest in natural philosophy.)
Chapter 1: definition of nature: the principle of motion and rest. (In modern terms, physics)
Chapter 30: nature is coalition and separation, or in other words, generation and corruption (biology)
ch 3: first principles.
- Thales-water,
- Anaximander-infinte,
- Anaximenes-air,
- Anaxagorus-homogeneities,
- Archelaus-air,
- Pythagorus-number,
- Heraclitus-fire,
- Epicurus & Democritus-atoms (greeks first thought of atoms!)
- Empedocles-earth/air/fire/water,
- Plato-god/matter/idea,
- Aristotle-form/matter/privation
ch 5: Stoics - the world is one, Metrodorus - infinite worlds
ch 6: "the world is spherical"
Knowledge and veneration of gods taught 3 ways-
- nature (philosophers)
- fables (poets)
- laws (constitution)
ch 7: definitions of god
- atheists existed back then too
- "god cannot do everything; for if it were so, then god could make the fire cold" -- Are God's powers limited? Can God create a stone he cannot lift?
- Thales - intelligence of the world is god
- Socrates & Plato - god is perfectly good, immaterial, not subject to passions
ch 9 & 10: matter is changeable; idea gives form to shapeless matter
ch 20 & 21: what are modern definitions of space and time? (these are still hard to define)
ch 24: Parmenides and Zeno - no change or motion (see Zeno's paradoxes)
ch 25 & 26: Democritus says necessity is "resistance, impulse, and force of matter" (anticipating Newton?)
ch 29: five causes (what are the differences):
- necessity
- fate
- choice and free-will
- fortune
- chance
Book 2
Nature of the world? infinite universe. spherical world.
Does the world have a soul or is it managed by natural laws?
ch 8: the world is inclined
what is beyond the world?
What is heaven? what are the stars?
How big is the sun? what is it made of ?
ch 24: solar eclipse. "And by mirrors it is make perspicuous that, when the sun is eclipsed, the moon is in a direct line below it." (Proof by empirical, experimental evidence!!)
Book 3
Mostly about whether.
Book 4
Interesting discussion on the soul, its nature, and its parts.
Book 5
This book has a lot about procreation. You may want to omit it.