Think - CH07

The World

Introduction

  • In the previous chapters, we explored six problem areas: global reliability, mind and body, freedom and fate, the self, God, and the order of nature.
  • This chapter delves into the difficulties that arise when thinking about the world around us.

Colors, Smells, Sounds, Feels, and Tastes

  • Galileo Galilei (1564-1642) distinguished between primary and secondary qualities of material things.
    • Primary qualities: shape, size, motion, and number - inseparable from substance.
    • Secondary qualities: colors, tastes, sounds, odors, and feels - reside only in the sensitive (perceiving) animal.
  • Descartes shared Galileo's view of the senses as unreliable vehicles of truth.
    • Sensory perceptions inform the mind of what is beneficial or harmful.
    • Misusing senses leads to misjudgments about the essential nature of bodies.
  • Descartes used the example of feeling pain in the foot to illustrate how God designed the mind to receive sensations conducive to the body's well-being.
  • Descartes denied epiphenomenalism (the mind is not inert) because mental events influence our actions (e.g., moving the foot quickly).
  • Evolutionary perspective (substituting evolution for God):
    • Creatures need information from the environment that aligns with their needs to flourish.
    • The specific experience doesn't matter as long as it stimulates the right action (e.g., fleeing from a predator).
    • Senses provide only "confused" data.
  • Descartes believed we are at fault if we misinterpret sensory data, which should not be treated as straightforward information about the real properties of things.
  • Descartes, as a mathematician, considered spatial extension the real property of "res extensa."
  • Dualism:
    • Manifest Image: The world as it is for us (colored, warm, smelly, noisy, comfortable, familiar).
    • Scientific Image: The world as it is objectively (physical particles and forces in space).

Argument from Perceptual Relativity

  • Relativism extends beyond moral philosophy and applies to tastes, odors, colors, sounds, and feels.
  • The argument:
    1. An object displays a certain smell to observer O, based on O's sensory structures.
    2. Another creature O* with different sensory structures could perceive the same object with a different smell.
    3. O and O* may live equally efficient lives.
    4. Therefore, there is no one correct distribution of smells in the world.
    5. Smells are better thought of as mind-dependent.
  • The argument does not require the actual existence of O*; the possibility is sufficient.
  • Examples:
    • Dogs and their world of smells.
    • Different sensitivities to tastes (e.g., beer, dry wine).
    • Color-blindness in mammals.
    • Varying taste sensitivities among humans.
  • Analogy: Different television sets receiving the same signal produce different outputs based on their structure.
  • Crucial premise: Different creatures may live equally well-functioning, adapted lives.
  • Without this premise, differing perceptions could be interpreted as one creature perceiving the world correctly while another misses information.
  • Evolutionary explanation: Creatures that cannot receive needed information die out.
  • Russell: It would be "favoritism" to say that the world is better represented in one way than another.
  • Counterargument: Some creatures may be better adapted for certain sensory dimensions (e.g., dogs for smell, humans for color vision).
  • Repairing the argument: Focus on each sensory dimension D (vision, touch, smell, sound, taste) separately. O and O* may each live equally efficient, adapted lives in respect of sensory dimension D.
  • The rationale for the final move: The world cannot contain as many smells as there are possible sensory apparatuses.

Good Solid Sense

  • Descartes believed reason could inform him about the properties objects really had, despite the illusory aspects of the world of appearance.
  • John Locke elaborated on this view in English-speaking philosophy.
  • Locke's distinction between primary and secondary qualities:
    • Primary qualities: solidity, extension, figure, motion or rest, and number.
    • Secondary qualities: colors, sounds, tastes, etc., are powers to produce sensations in us, dependent on primary qualities.
  • Locke's picture includes a scientific world of particles with primary properties and a manifest image that is largely due to the mind.
  • Objects have the powers to produce colors and smells in us, but these powers are not the colors and smells themselves.
  • Locke's view: Sensations in us do not resemble the powers that give rise to them.
  • This view is often seen as common-sense scientific realism, although the opposition between the scientific world and the manifest image remains.

Berkeley's Problems

  • French writers questioned whether God might deceive us about primary qualities, just as he does with secondary qualities.
  • This raises an epistemological problem: Colors become a Trojan horse, reintroducing general Evil Demon skepticism.
  • Metaphysical issues arise when considering the scientific world.
  • Descartes banished all qualities except extension but extension is abstract and needs things occupying space to be meaningful.
  • Locke included properties like solidity and motion, but motion requires things moving.
  • Solidity is understood through touch and resistance, but can we be content with a world of different regions of space with different powers?
  • Do we need a substance to possess these powers?
  • Locke suggests solidity is known by what we feel (e.g., touching a flint or football and trying to join the hands).
  • The problem: How is solidity not analogous to color, heat, or smell?
  • Berkeley argues this undermines the possibility of any resembling property in the world.
  • Berkeley's subjective idealism: The world retreats entirely into the mind.
  • Locke's view requires us to conceive of a world in purely primary-quality terms, but can we do this?
  • Berkeley denies that we can abstract qualities from each other.
  • Hume: We cannot understand the alleged properties of the independent world except in terms of our own experience.
  • Scientific worldview requires making sense of an absolute conception of reality in terms of space-occupying things, but this conception may be flawed. Nothing remains once secondary qualities have been removed.

Forces, Fields, and Things

  • Hume questions what conception we have of bodies, apart from their powers of interaction.
  • Faraday argued that we cannot form a notion of a nucleus independent of its powers.
  • The world of physics resolves into a vast flux of forces (gravitational, electromagnetic, strong and weak interactions).
  • Problem: Normally, we understand forces in terms of the acceleration that would occur if some test particle were placed in a field; the existence of the magnetic field around it is a matter of the way in which other