kant by xiaohuicaicai

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									                                                11/27/06




Immanuel Kant
   (1724-1804)




  The Critique of Pure Reason
                 (1781, 1787)


                                (Text, pp. 341-363)
                                                      1
Anthem




         2
Topics covered in the reading
1 The nature, scope,
  & limits of human
                                2 The transcendental
  knowledge
                                  ideas of pure reason:
   a priori & a posteriori
    knowledge                     self, cosmos, & God
   analytic & synthetic
    judgments
   synthetic a priori          3 Morality & metaphysics:
    judgments & how they          freedom, immortality, &
    are possible
                                  God
   phenomena, noumena, &
    the "transcendental ideas
    of pure reason"


                                                            3
Introductory Note

            What is knowledge?

  Answer: Knowledge is verified
    ("justified") true belief.
      To know is to believe;
      the belief must be true (rather than false);
       and
      the belief must be verified ("justified"), i.e.,
       proved true.


                                                          4
 The Rationalist-Empiricist Dispute



               According to Kant,

 all knowledge begins with sense
experience, but not all knowledge
  arises out of sense experience.



                                      5
There are two basic types of
    human knowledge:

 a posteriori        a priori knowledge,
  knowledge, which     which arises from
  arises from &        the operations of
  depends on sense     the mind & is
  experience; and      independent of
                       sense experience



                                             6
The distinguishing characteristics
  of pure a priori knowledge:

         Necessity


          and

         Strict universality
          (no possibility of an
          exception)

                                  7
 A priori judgments are
necessarily & universally
 true (or false),       whereas


      a posteriori (empirical)
       judgments are never
   necessarily or universally true
            (or false).*
          *They are contingently true (or false).
                                                    8
A further Kantian distinction


   Analytic Judgments
            vs.
  Synthetic Judgments


                                9
It's all about subjects
      & predicates


                          10
In an analytic judgment
     or proposition,

         the predicate makes explicit
        (explicates) meanings that are
     already implicit in the subject (e.g.,
          "a triangle is three-sided").

                                              11
   In a synthetic judgment or
          proposition,
 the predicate adds
  to our knowledge of
  the subject in a way
  that logical analysis,
  by itself, cannot         The predicate of a
  (e.g., "some houses        synthetic proposition
  are white").               augments & amplifies
                             our knowledge of the
                             subject.

                                                     12
 The relationships between
analytic, synthetic, a priori, &
   a posteriori judgments



                                   13
Analytic judgments express a priori
     knowledge, i.e., they are
  necessarily & universally true
             (or false),
    & they can be verified or falsified
   independently of sense experience,
      i.e., by logical analysis alone.

                    (There is no need to test
                    them a posteriori.)
                                                14
"Material objects are
extended in space."

          This proposition is both
          analytic & a priori.

                                 15
   A posteriori judgments
(which must be verified or falsified on
   the basis of sense experience,
    not through logical analysis)


           are always synthetic
  (e.g., "material objects have weight").


                                          16
So . . . .
             17
               there are
              (uncontroversially)


 analytic a priori judgments,


 synthetic a posteriori judgments, and


 analytic a posteriori judgments (which are
  a waste of time, since analytic judgments can be
  verified or falsified by logical analysis alone).

                   In addition to these, Kant claims . . . .
                                                           18
   that there are



synthetic a priori
   judgments
            (This is controversial!)
                                       19
 A synthetic a priori judgment
        is one that is
 necessarily & universally true (& thus not
  derived from sense experience, i.e., it is
  a priori)
 and in which
 the predicate adds something to our
  knowledge of the subject that could not be
  known merely by logical analysis of the
  subject.
                                               20
Examples of synthetic a priori judgments
                   (according to Kant)


   "Everything that happens has a cause."
   "7 + 5 = 12"
   "A straight line is the shortest distance
    between two points [in space]."
   "In all changes of the material world, the
    quantity of matter remains unchanged."
   "In all communication of motion, action and
    reaction must always be equal."
   "The world must have a beginning."

                                                  21
    This leads to what Kant calls



"the general problem of pure reason"


                                  22
23
To this general question, Kant adds
   several subsidiary questions:


 "How is pure mathematical science possible?"

 "How is pure natural science [physics] possible?"

 "How is metaphysics as a natural disposition
  possible?"
 "How is metaphysics as a science possible?"

     (We will not at this time pursue answers to these questions.)
                                                              24
            Kant's solution of




How are synthetic a priori judgments possible?


                                            25
Kant's "Copernican Revolution
        in Philosophy"




                     Objects
                ?
         Mind



                                26
  According to Kant,


  the mind does not conform to its
objects. On the contrary, the objects
  of consciousness conform to the
 structure & operations of the mind
               itself.


                                        27
 The structure of the mind

                  Pure
                 Reason
                (Vernunft)
                         Understanding
                          (Verstand)

                  Categories        Sensibility
                                 (Sinnlichkeit)
Categories
of the Under-                  Forms of
                               space &    Forms of
standing                       time       Sensibility
                                                        28
                Kant's overall view
       Transcendental Ideas      (Rational Belief)
       & Moral Postulates
                                                     Noumena
    Reason
   (Vernunft)      Understanding               Objects of
                                               Consciousness
                    (Verstand)

            Categories                       Phenomena
Mind                        Sensibility
                         (Sinnlichkeit)
                    Forms of
                    space &
                    time
                              (Knowledge)
                                                               29
 Categories of the Understanding

1 Of Quantity                   3 Of Relation
   Unity (Singularity)            Substance-Attribute
   Plurality (Particularity)      Cause-&-Effect
   Totality (Universality)        Community (Interaction)


2 Of Quality                    4 Of Modality
   Affirmation                    Possibility-Impossibility
   Negation                       Existence-Nonexistence
   Limitation                     Necessity-Contingency


                                                           30
  The categories of the
     understanding

  are applicable only to phenomena
that appear to us under the forms of
      sensibility (space & time);

     they have no legitimate application to
     noumena, i.e., realities or alleged realities
     that transcend the realm of space & time.

                                                     31
           However,

 in an effort to construct a totally
  unified, coherent, & systematic world-
  view,
 human reason (Vernunft) thinks beyond
  the phenomenal realm
 and formulates ideas of realities (i.e.,
  possible realities) that transcend the
  world of experience.
                                             32
This takes us



                33
from knowledge to

rational belief
       The transcendental
       metaphysics of Pure Reason


                                    34
The Transcendental Ideas
     of Pure Reason

     Self, Cosmos, & God




                           35
 The content of the
transcendental ideas

                       36
The Transcendental Idea of
         the Self
 a thinking substance (soul)
 simple & unchangeable
 has a personal identity that persists
  through time
 exists in relation to other real things
  outside it
 experiencer & thinker

                                            37
  The Transcendental Idea of
          the Cosmos
     (or world-in-general)



a unified and infinitely long series of events

       the totality of all causal series

                                             38
The Transcendental Idea of
           God



              The primordial,
               single, self-
               subsistent, all-
               sufficient, supreme

              ground of being
              Supreme creative
               & purposive reason
               as the cause of the
               universe
                                     39
The Justification of the
Transcendental Ideas


  They are the foundations for reason's
      construction & account of the
     systematic unity of experience.


                                      40
   The Idea of the Self enables
       reason to construe
 all of "my" subjective experiences as existing in a
  single subject (my "self"),
 all of "my" powers of perception & thought as
  derived from a single source (my "self"),
 all changes within "me" as belonging to the states
  of one & the same permanent being (my "self"),
  and
 all phenomena in space as entirely different from
  the activity of thought (i.e., as other than my
  "self").
                                                    41
In other words, the idea of
          the Self


 provides me with a metaphysical
  foundation for the unity of my
           experience.


                                   42
The Idea of the Cosmos
  enables reason to

     think of the world as if it were a
 unified collection or totality of infinitely
      long causal series that can be
   endlessly investigated by science.
           In other words, the idea of the cosmos-as-a-
           whole is a stimulus to scientific inquiry.
                                                          43
    The Idea of God enables
      reason to see nature
 as a system
  grounded in reason

                        since God is
 and                    Supreme Reason

 pervaded with         aiming at
  purpose
                        the ultimate good of
                         all things.
                                           44
            In other words,

 the idea that God (a    enables us to see
 supremely rational &      the world as a
 purposive being) is       teleological
 the cause (creator)       unity
 of the universe
                          in which everything
                           (absolutely every-
                           thing) serves some
                           purpose.
                                               45
Kant seems to be saying that,

 unless we assume the existence of the
  Self (transcendental ego), the Cosmos-
  as-a-whole, & God,
 the world & our experience of the world
 will lack systematic unity & coherence.
           In other words, the world & our experience of
           the world cannot be completely intelligible (or
           meaningful) without the transcendental ideas of
           pure reason.
                                                         46
However . . . ,

              47
  the transcendental ideas
                                      are "regulative,"
                                     not "constitutive."
That is, they guide or "regulate" our study
of the world by leading us to proceed AS IF
the Self, the Cosmos-as-a-whole, & God are
real.
               However, the objects of the transcendental ideas
               (Self, Cosmos, & God) do not "constitute" actual
               objects of experience; they are "merely" ideal
               objects, which, if real, add systematic unity &
               coherence to our experience of the phenomenal
               world.
                                                            48
  But we cannot KNOW
whether or not the Self, the
 Cosmos, & God are real
          because they are "transcendental"
        (noumenal) objects, i.e., they are not
       phenomena that appear in space & time
           & to which the categories of the
            understanding can be applied.


                                                 49
Morality, Happiness, &
    Metaphysics



  Freedom, Immortality, & God
           (The Postulates of Practical Reason)

                                            50
Kant's distinction between

   theoretical reason (reasoning about
   the universe, the world of nature)

   and


   practical reason (reasoning about
   human existence & action)

                                          51
      As we have seen,

   pure reason (i.e., pure theoretical
 reason), in seeking to understand the
universe as a whole, formulates certain
         "transcendental ideas"
           (of Self, Cosmos, & God).




                    Similarly . . . ,
                                          52
       pure practical reason,
 in an effort to see
 human existence &           postulates
 human moral effort             the reality of moral
 as meaningful,                 freedom, the
                                immortality of the
                                soul, & the existence
                                of God.
             (In the Critique of Practical Reason (1788),
             Kant calls freedom, immortality, & God "the
             postulates of practical reason.")
                                                        53
Freedom of the Will

     According to Kant,
       morality (the moral law)
  tells us what we OUGHT to do.

           Thus, morality presupposes
           freedom of the will
                  because, logically speaking,
                  "ought" implies "can."
                                           54
The existence & nature of the
          moral law
  In the Critique of Pure Reason, Kant
   assumes the existence of pure a priori
   moral laws that determine what we
   ought and ought not do.
  In his later works on ethical theory
   (see footnote on p. 358 in text), he seeks to
   deduce the moral law from the concept
   of moral duty (or obligation).

                                                   55
  According to Kant,

 reason discerns a relationship
between morality & happiness.




             What is the nature of
             that relationship?

                                     56
             On this subject,

 there is a difference between the
 pragmatic law & the moral law.

The pragmatic law
answers the question,       The moral law
"What must I do in          answers the
order to become             question, "What
happy?"                     must I do in
                            order to deserve
                            (be worthy of)
                            happiness?"
                                               57
           Moral laws are

 categorical
 imperatives,
 i.e., absolute &       hypothetical
 unconditional moral    imperatives (e.g.,
 commands (e.g.,        "If you wish to have
 "Be honest");          a good reputation,
                        be honest").
 they are NOT


                                               58
In general, the moral law says,


    "Do that through which you
   become worthy of happiness."



                                  59
       Reason is not satisfied

 with morality all by
  itself,                 In a completely good
                           world, "a system in
 nor with                 which happiness is tied
                           and proportioned to
                           morality [which makes
 happiness all by
                           one worthy of
  itself.
                           happiness] would be
                           necessary."

                                                     60
 "What . . . is the supreme
good of the moral world that
 a pure but practical reason
 commands us to occupy?"

     "It is happiness in exact proportion to
     the moral worth of the rational beings
            who populate that world."



                                          61
   For such an ideal world to exist, two
          things are necessary:
 the existence of God;
                           Only God can guarantee
 and
                            the ideal proportionality of
 the immortality of        morality & happiness.
  the soul.                If happiness &
                            unhappiness are to be
                            necessary consequences of
                            our conduct in the
                            empirical world, then there
                            must be a future world in
                            which the soul lives on.
                                                      62
That’s all,
 folks!

              63

								
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