Concerning Nature, by Plutarch

Book I.

1. What is Nature?
2. What is the Difference between a Principle and an Element?
3. What are Principles?
4. How was this World Composed in that Order and after that Manner it is?
5. Whether the Universe is One Single Thing.
6. Whence did Men obtain the Knowledge of the Existence and Essence of a Deity?
7. What is God?
8. Of those that are called Geniuses and Heroes
9. Of Matter.
10. Of Ideas.
11. Of Causes.
12. Of Bodies.
13. Of those Things that are Least in Nature.
14. Of Figures.
15. Of Colors.
16. Of the Division of Bodies.
17. How Bodies are Mixed and Contemperated one with another.
18. Of a Vacuum.
19. Of Place.
20. Of Space.
21. Of Time.
22. Of the Substance and Nature of Time.
23. Of Motion.
24. Of Generation and Corruption.
25. Of Necessity.
26. Of the Nature of Necessity.
27. Of Destiny or Fate.
28. Of the Nature of Fate.
29. Of Fortune.
30. Of Nature.

Book II.

1. Of the World.
2. Of the Figure of the World.
3. Whether the World be an Animal.
4. Whether the World is Eternal and Incorruptible.
5. Whence does the World receive its Nutriment?
6. From what Element God did begin to raise the Fabric of the World.
7. In What Form and Order the World was Composed.
8. What is the Cause of the World’s Inclination.
9. Of that Thing which is Beyond the World, and whether it be a Vacuum or not.
10. What Parts of the World are on the Right Hand, and what on the Left.
11. Of Heaven, what is its Nature and Essence.
12. Into how many Circles is the Heaven Distinguished; or, of the Division of Heaven.
13. What is the Essence of the Stars, and how they are Composed.
14. Of what Figure the Stars are.
15. Of the Order and Place of the Stars.
16. Of the Motion and Circulation of the Stars.
17. Whence do the Stars receive their Light?
18. What are those Stars which are called the Dioscuri, The Twins, or Castor and Pollux?
19. How Stars Prognosticate, and what is the Cause of Winter and Summer.
20. Of the Essence of the Sun.
21. Of the Magnitude of the Sun.
22. What is the Figure or Shape of the Sun.
23. Of the Turning and Returning of the Stars, or the Summer and Winter Solstice.
24. Of the Eclipse of the Sun.
25. Of the Essence of the Moon.
26. Of the Size of the Moon.
27. Of the Figure of the Moon.
28. From whence is it that the Moon receives Her Light?
29. Of the Eclipse of the Moon.
30. Of the Phases of the Moon, or the Lunar Aspects; or How it comes to pass that the Moon appears to us Terrestrial.
31. How far the Moon is removed from the Sun.
32. Of the Year, and how many Circulations make up the Great Year of Every Planet.

Book III.

1. Of the Galaxy, or the Milky Way.
2. Of Comets and Shooting Fires, and those which resemble Beams.
3. Of Violent Eruption of Fire out of the Clouds. Of Lightning. Of Thunder. Of Hurricanes. Of Whirlwinds.
4. Of Clouds, Rain, Snow, and Hail.
5. Of the Rainbow.
6. Of Meteors which resemble Rods, or of Rods.
7. Of Winds.
8. Of Winter and Summer.
9. Of the Earth, what is its Nature and Magnitude.
10. Of the Figure of the Earth.
11. Of the Site and Position of the Earth.
12. Of the Inclination of the Earth.
13. Of the Motion of the Earth.
14. Into how many Zones is the Earth Divided?
15. Of Earthquakes.
16. Of the Sea, and how it is Composed, and how it becomes to the Taste Bitter.
17. Of Tides, or of the Ebbing and Flowing of the Sea.
18. Of the Aurea, or a Circle about a Star.

Book IV.

1. Of the Overflowing of the Nile.
2. Of the Soul.
3. Whether the Soul be a Body, and what is the Nature and Essence of it.
4. Of the Parts of the Soul.
5. What is the Principal Part of the Soul, and in what part of the Body it resides.
6. Of the Motion of the Soul.
7. Of the Soul’s Immortality.
8. Of the Senses, and of those Things which are Objects of the Senses,
9. Whether what Appears to our Senses and Imaginations be True or Not.
10. How many Senses are there?
11. How the Actions of the Senses, the Conceptions of our Minds, and the Habit of our Reason are Formed.
12. What is the difference between Imagination, the Imaginable, Fancy, and Phantom?
13. Of our Sight, and by what means we See.
14. Of those Images which are presented to our Eyes in Mirrors.
15. Whether Darkness can be Visible to us.
16. Of Hearing.
17. Of Smelling.
18. Of Taste.
19. Of the Voice.
20. Whether the Voice is Incorporeal. What is it that gives the Echo?
21. By what means the Soul is Sensible, and what is the Principal and Commanding part of it.
22. Of Respiration or Breathing.
23. Of the Passions of the Body, and whether the Soul hath a Sympathetical Condolency with it.

Book V

1. Of Divination.
2. Whence Dreams do Arise.
3. Of the Nature of Generative Seed.
4. Whether the Sperm be a Body.
5. Whether Women do give a Spermatic Emission as Men do.
6. How it is that Conceptions are Made.
7. After what manner Males and Females are Generated.
8. By what means it is that Monstrous Births are Effected.
9. How it comes to pass that a Woman’s Too Frequent Conversation with a Man hinders Conception.
10. Whence it is that One Birth gives two or three Children.
11. Whence it is that Children represent their Parents and Progenitors.
12. How it comes to pass that Children have a Greater Similitude with Strangers than with their Parents.
13. Whence ariseth Barrenness in Women, and Impotency in Men?
14. How it arises that Mules are Barren.
15. Whether the Infant in the Mother’s Womb be an Animal.
16. How Embryos are Nourished, or how the Infant in the Belly receives its Aliment.
17. What Part of the Body is first formed in the Womb.
18. Whence is it that Infants born in the Seventh Month are born alive.
19. Of the Generation of Animals, how Animals are Begotten, and whether they are Obnoxious to Corruption.
20. How many Species of Animals there are, and whether all Animals have the Endowments of Sense and Reason.
21. What Time is Required to Shape the Parts of Animals in the Womb.
22. Of what Elements each of the Members of us Men is Composed.
23. What are the Causes of Sleep and Death?
24. When and from whence the Perfection of a Man Commences.
25. Whether Sleep or Death appertains to the Soul or Body.
26. How Plants Increase.
27. Of Nutrition and Growth.
28. Whence it is that in Animals there are Appetites and Pleasures.
29. What is the Cause of a Fever, or whether it is an Affection of the Body annexed to a Primary Passion
30. Of Health, Sickness, and Old Age.