Idealism

1
Idealism

2
The Atomic Theory of Matter

• The atomic theory poses a challenge to theories
  of substances or objects
• Atomic theory things are composed of atoms
  properties of things depend on nature and motion
  of atoms
• Things are not as they appear

3
Dignaga (c. 450), Buddhist

• Though atoms serve as causes of the
  consciousness of the sense-organs, they are not
  its actual objects like the sense organs because
  the consciousness does not represent the image of
  the atoms. The consciousness does not arise from
  what is represented in it. Because they do not
  exist in substance just like the double moon.
  Thus both the external things are unfit to be the
  real objects of consciousness.

4
Actual and Internal Objects

• Aristotle objects cause perceptions, and are
  represented in them
• Causes of perception objects of perception
• Dignaga No
• causes are the atoms actual objects alambana
• objects are appearances internal objects artha

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Causes and Effects

• Causes of perception are the atoms
• We dont see atoms, but their effects
• What we see doesnt exist in reality it is like
  the double moon
• How can we distinguish the aspects of the effects
  (appearances) that do match the causes?

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Primary Qualities

• Descartes We perceive clearly and distinctly
  only the mathematical properties of objects
  size, shape, motion
• Only they reflect the true natures of things
• Locke Primary qualities are inseparable from
  objects atoms have them
• Primary qualities are those objects possess
  according to the atomic theory of matter
• They produce simple ideas in us that resemble the
  primary qualities in the objects

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Secondary Qualities

• Secondary qualities are effects of objects on our
  nervous systems
• They produce ideas in us that do NOT resemble
  them
• Secondary qualities depend on primary qualities
• Secondary qualities are response-dependent to
  have one is just to produce a certain effect in a
  perceiver

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Real and Nominal Essence

• Aristotle and Aquinas identify
• The essence of x the properties necessary to x
• The quiddity of x the definition of x in re
• The nature of x what makes x what it is
• Locke nominal essence quiddity uses secondary
  qualities
• Real essence nature real internal constitution

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Idealist Critique

• Dignaga We know world only through sense organs
• So, we know objects only insofar as they become
  internal objects
• They are objects of consciousness, constituted by
  consciousness
• We know objects only as conditioned by
  consciousness

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Argument for Idealism

• We have reason to believe that something exists
  only if we can know it
• We can know an object only by making it an object
  of consciousness
• Any object of consciousness is conditioned by
  consciousness
• Anything conditioned by consciousness is
  mind-dependent
• So, we have reason to believe that a thing exists
  only if it is mind-dependent

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George Berkeley (1685-1753)

• Idealism best defense of common sense against
  scepticism
• Descartess and Lockes ideas of objects make no
  sense
• Attack on primary qualities and on substance

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Against Primary Qualities

• We have no basis for thinking any of our ideas
  corresponds to some mind-independent reality
• We cannot judge resemblance to reality
• Perceptions of width, height, etc., vary while
  objects remain unchanged

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Esse est Percipi

• We have access only to what is before the mind
• A thing can exist only if it is perceived
• Do things go out of existence when we arent
  looking at them? No because God keeps an eye on
  them for us

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Kants Copernican Revolution

• Rationalists universality and necessity require
  synthetic a priori
• Hume source not in the world but in us
• Kant source is within us but it is reason, not
  custom or habit

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Kants Categories

• There are innate concepts the categories
• They are logical forms of judgment
• They apply only to experience

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Knowledge gt Objects

• It has hitherto been assumed that our knowledge
  must conform to the objects but all attempts to
  ascertain anything about these objects a priori,
  by means of concepts, and thus to extend the
  range of our knowledge, have been rendered
  abortive by this assumption. Let us then make the
  experiment whether we may not be more successful
  in metaphysics, if we assume that the objects
  must conform to our knowledge.

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Kant Copernicus

• We here propose to do just what Copernicus did
  in attempting to explain the celestial movements.
  When he found that he could make no progress by
  assuming that all the heavenly bodies revolved
  round the spectator, he reversed the process, and
  tried the experiment of assuming that the
  spectator revolved, while the stars remained at
  rest. We may make the same experiment with regard
  to the intuition of objects. If the intuition
  must conform to the nature of the objects, I do
  not see how we can know anything of them a
  priori. If, on the other hand, the object
  conforms to the nature of our faculty of
  intuition, I can then easily conceive the
  possibility of such an a priori knowledge.

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Laws of the Understanding

• Before objects, are given to me, that is, a
  priori, I must presuppose in myself laws of the
  understanding which are expressed in concepts a
  priori. To these concepts, then, all the objects
  of experience must necessarily conform.

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Limits of Knowledge

• . . . we only know in things a priori that which
  we ourselves place in them.
• Laws that govern realm of experience are in us
  the laws of the understanding
• So, we can know things only as experienced by us
  not as they are in themselves

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Kants Rationalism

• There are innate ideas pure concepts of the
  understanding (the categories)
• There are synthetic a priori truths (laws of the
  understanding)
• But they apply only within realm of experience

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Phenomena

• Phenomena appearances, objects as we perceive
  them
• Categories apply to them
• A priori principles apply to them
• We can know them with universality and necessity

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Noumena

• Noumena things-in-themselves, unconditioned by
  our cognitive faculties
• Categories dont apply to them
• A priori principles dont apply to them
• We cant know them at all

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Descartes/Hume/Kant

• Descartes Hume Kant
• Synthetic
• a priori? Yes No Yes
• Knowledge
• Beyond exp. Yes No No
• Knowledge
• of world as Yes No No
• it is

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Platos Philosophy of Mind

The Good
Participation
This is a triangle
Form
Recollection
Perception
Object
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Kants Philosophy of Mind

Construction
This is a triangle
Concept
Perception
Object
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Kants Philosophy of Mind

Understanding
This is a triangle
Concept
Appearance
Sensibility
Thing in itself