aristotle physics book2 ch 1-3

Chapter 1: Nature and Existence

• There are two categories of existence:

  • By Nature:

  • Animals, plants, and simple bodies (e.g. earth, fire, air, water) exist by nature.

  • Characteristic: They have an innate principle of motion and rest (e.g. growth, decrease, alteration).

  • Not By Nature:

  • Products of human craftsmanship (e.g. beds, coats) do not have a natural impulse to change.

  • They may be composed of materials that possess their own innate principles (e.g. stone, earth) but only in virtue of those materials—not because they inherently possess such a nature.

• Principle of Motion:

  • Nature serves as the source of movement and rest for entities that possess it intrinsically (as opposed to external attributes).

  • Example: A doctor who is also a patient is not a patient due to his profession but due to an external condition; hence, nature is not an attribute but an intrinsic quality.

• Substance and Nature:

  • Only those objects or beings with a principle of motion are considered substances.

  • Nature implies a subject where it exists; thus, the term "according to nature" includes both the physical objects and their respective attributes.

• Obviousness of Nature:

  • The existence of nature cannot reasonably be argued as it's evident from numerous examples.

  • Caution against proving obvious truths through complex reasoning, comparing it to a blind person's reasoning about colors without experience.

• Nature as Constituents:

  • Some identify nature with the fundamental constituents of an object, e.g. wood is the nature of a bed.

  • Antiphon states that if a bed were planted, it would yield wood, indicating that the arrangement (the furniture) is less significant than the material itself (the wood).

Chapter 2: Nature and the Mathematician vs. Physicist

• Different Uses of Nature:

  • Nature corresponds to both the material substratum and the specified shape/form of an entity.

  • Definition: A bed is only considered a bed when it possesses the proper shape (not merely the wood).

• Comparison Between Disciplines:

  • Physicists study the nature of physical bodies including their attributes and relationships (e.g. spherical shapes of celestial bodies).

  • Mathematicians, however, consider these bodies in abstraction and do not focus on attributes that include physical motion.

• Physics and Mathematics Relationship:

  • Geometry addresses physical lines abstractly, whilst optics examines light in a physical context but not mathematically.

  • Understanding entails examining both material and formal aspects of objects.

• Unity of Nature:

  • Physicists should understand both form and matter to grasp the full nature of an object.

  • Nature is the end, or the ultimate purpose, of inquiry into physical change.

• Arts and Natural Products:

  • In art, the process may direct the manipulation of natural materials, but in nature, the material exists inherently.

  • A revision of scientific methods is needed for understanding both aspects of nature.

Chapter 3: Understanding Causes

• Causation in Inquiry:

  • Knowledge requires understanding the 'why' behind existence, necessitating a grasp of primary causes.

• Types of Causes:

  • 1. Material Cause: The substance out of which a thing is made (e.g. bronze of a statue).

  • 2. Formal Cause: The archetype or essence of the entity (e.g. the design of a statue).

  • 3. Efficient Cause: The agent responsible for change (e.g. the sculptor).

  • 4. Final Cause: The purpose or intended outcome of an action (e.g. health is the end goal of medical procedures).

• Reciprocal Causation:

  • Causes can affect each other reciprocally, e.g. the relationship between hard work and fitness.

• Complexity of Causes:

  • Different causes may simultaneously affect one result, each contributing differently (e.g. sculptor and the bronze both contribute to the statue).

  • Events can also have conflicting causes leading to opposing results.

• Categories of Causes:

  • Causes can be categorized into four divisions: letters as causes of syllables, material of products, parts of wholes, and premises of conclusions.

  • Each division may reflect different modes of causation (e.g. one set being the substrate and the other essence).

• Incidental Attributes and Causes:

  • Incidental attributes can also form a causal connection providing more nuanced interpretations (e.g. recognizing a statue beyond just 'being a sculptor').

• Modes of Causation:

  • Distinctions are made between different types of causation including potential vs. actual causes.

  • Investigating the most precise cause is essential for clarity in understanding change and creation.