Chapter 7 Are There Limits To Cognition?

 
    Chapter 7
         Are There Limits
            To Cognition?

 
    [1] We have established
          that the elements
             for the explanation
                of reality
            are
               to be found
                  in two spheres:
       perceiving
          and thinking.

    It is due,
       as we
          have seen,
       to our organization
          that the full,
             complete reality,
                including our own selves
                   as subjects,
       appears at first
           as a duality.

    Cognition
        overcomes
           this duality
              by fusing
                 the two elements
               of reality,
       the percept
          and the concept
        gained
           by thinking,
       into the complete thing.

    Let us
          call the manner
         in which
            the world
               presents itself to us,
       before it
          has taken on
             its true nature
           through cognition,
        "the world
           of appearance,"
              in contrast
                 to the unified whole composed
                    of percept and concept.

    We can then say:
        The world
           is given
              to us
                 as a duality,
      and
         cognition transforms it
            into a unity.

    A philosophy
          which starts from this
             basic principle
                may be called
                   a monistic philosophy,
       or monism.

    Opposed
        to this
           is
       the two-world theory,
      or dualism.

    The latter
        does not assume just
           that there are
              two sides
                 of a single reality
         which
            are kept
           apart
              merely by our organization,
       but
          that there are two worlds
             absolutely distinct
           from one another.

    It
         then tries
            to find
           in one
               of these two worlds
                   the principles
               for the explanation
                   of the other.
 
    [2] Dualism
        rests
           on a false conception
               of what
                  we
          call cognition.

    It divides
        the whole
           of existence
              into two spheres,
      each
         of which
            has
         its own laws,
      and
         it leaves
            these two worlds standing
          apart and opposed.
 
    [3] It is
        from a dualism
            such as this
           that there arises
              the distinction
            between the perceptual object
                and the thing-in-itself,
      which
         Kant introduced
            into philosophy,
          and which,
             to the present day,
      we have not succeeded
          in eradicating.

    According to
        our line
            of argument,
      it is
          due to the nature
              of our mental organization
                 that a particular thing
                    can be given
                  to us
         only
        as a percept.

    Thinking
         then overcomes
            this particularity
           by assigning
              to each percept
                 its rightful place
               in the world
                   as a whole.

    As long
        as we designate
       the separated
          parts
             of the world
            as percepts,
      we are simply following,
         in this
            separating out,
      a law
         of our subjectivity.

    If,
       however,
          we regard the sum
             of all percepts
                as the one part,
       and contrast
           with this
              a second part,
       namely,
          the things-in-themselves,
       then we
          are philosophizing into the blue.

    We are merely playing
        with concepts.

    We construct
        an artificial pair of
           opposites,
      but
         we can gain
            no content
          for the second
              of these
                  opposites,
      since such content
          for a particular thing
             can be drawn only
                from perception.

    [4] Every kind
        of existence
           that is assumed
              outside the realm
                 of percept and
                    concept
                       must be relegated
                    to the sphere
                        of unjustified hypotheses.

    To this category
        belongs the
           "thing-in-itself".

    It is quite natural
         that a dualistic thinker
            should be unable
          to find
              the connection
           between the world principle
         which
             he hypothetically assumes
                and
                   the things given
                      in experience.

    A content
        for the hypothetical world principle
           can be arrived
        at
            only by
               borrowing it
        from the world
            of experience
                and then shutting one's eyes
                    to the fact
                        of the borrowing.

    Otherwise
          it remains an empty concept,
       a non-concept
          which has nothing
         but the form
            of a concept.

    Here the dualistic thinker
          usually asserts that
         the content
            of this concept
               is inaccessible
           to our cognition;
              we can know only
          that
         such
             a content exists,
       but not
          what it
              is that exists.

    In both cases
         it is impossible
            to overcome dualism.

    Even though
         one
        were
           to import
          a few abstract elements
             from the world
                of experience
               into the concept
                   of the thing-in-itself,
       it would still remain impossible
          to derive
              the rich concrete life
           of experience
              from these
             few qualities
         which are,
            after all,
           themselves
        taken
           from perception.

    DuBois-Reymond
        considers
           that the imperceptible atoms
              of matter produce sensation
            and feeling
           by means
              of their position
                 and motion,
       and
          then comes
             to the conclusion
                that
                   we can never find
                      a satisfactory explanation
               of how matter and
                  motion produce sensation
                     and feeling,
       for "it
          is absolutely and
             for ever incomprehensible
                that it should be other
              than indifferent
           to a number
               of atoms
                   of carbon,
                      hydrogen,
                   nitrogen,
                      and so on,
                   how they
        lie and move,
                   how
         they lay
            and moved,
       or
          how
             they will lie
                and will move.

    It is impossible
          to see how
              consciousness
                 could come
           into existence
               through their interaction."

    This conclusion
        is characteristic
           of this whole trend
               of thought.

    Position
        and
           motion
              are abstracted
            from the rich world
                of percepts,
      They
         are
        then transferred
           to the notional world
              of atoms.

    And
         then
             astonishment arises
                that real life
                   cannot be evolved
           out of this self-made principle
              borrowed
                 from the world
                    of percepts.
 
    [5]
         That the dualist
            can reach no explanation
               of the world,
       working
          as he
             does
           with a completely empty concept
              of the "in-itself"
           of a thing,
       follows at
           once from the very
         definition of his principle
            given above.
 
    [6] In every
          case
             the dualist
            finds himself
                compelled
           to set impassable barriers
              to our capacity
                 for cognition.

    The follower
        of a monistic world conception
           knows
          that everything
             he
                needs for the explanation
                   of any given phenomenon
                       in the world
                          must lie
           within this world
               itself.

    What prevents him
        from reaching
       it can be only
          accidental limitations
        in space
           and time,
      or defects
          of his organization,
      that is, not
          of human organization
              in general,
      but
         only of his own particular one.
 
    [7] It follows
        from the concept
            of cognizing,
      as we
         have defined it,
      that one
         cannot speak
            of limits
          to cognition.

    Cognizing is not a concern
        of the world
            in general,
      but an affair
         which man
            must settle
               for himself.

    Things
          demand no explanation.

    They exist
          and act
             on one another
          according to
             laws
         which
            can be discovered
               through thinking,
       They
          exist
             in indivisible unity
                with these laws.

    Our Egohood
        confronts them,
       grasping
           at first only
         that part of them
             we have called percepts.

    Within our Egohood,
       however,
          lies the power
             to discover
                the other part
                   of the reality
               as well.

    Only
         when the Egohood
            has taken
               the two elements of reality
         which
            are indivisibly united
           in the world and
              has combined them also
                 for itself,
       is cognitive satisfaction
          attained
       -- the I
          has
         then arrived
            at the reality once more.
 
    [8] Thus the conditions necessary
        for cognition
       to take place
      are there through the I
         and
        for the I. The I
           sets itself
       the problems
          of cognition;
      and
         moreover
            it
         takes them
            from an element
           that is
         absolutely
             clear
                and transparent
          in itself:
      the element of thinking.

    If
         we set ourselves
            questions
         which
             we cannot answer,
       it must be
          because
             the content of the questions
                is not
               in all respects
                  clear and distinct.

    It is not the world
          which sets us the questions,
       but we ourselves.
 
    [9] I can imagine
         that it
            would be quite impossible
           for me
          to answer
              a question
         which
             I happened
                to find written down somewhere,
       without knowing
           the sphere
              from
         which
             the content
                of the question
                   was taken.
 
    [10] Our cognition
        is concerned
           with questions
         which
              arise
           for us
               through the fact
         that a sphere
            of percepts,
           conditioned
              by place,
           time,
              and our subjective organization,
       is confronted
           by a sphere
               of concepts
                  pointing
                     to the totality
                        of the universe.

    My task
        consists
           in reconciling
          these two spheres,
       with both
          of which
             I am well acquainted.

    Here one
          cannot speak
             of a limit
                to cognition.

    It may be that,
       at any particular moment,
          this or that remains
        unexplained
           because,
       through our place
           in life,
       we are prevented
           from perceiving
          the things involved.

    What is not found today,
       however,
          may be found
             tomorrow.

    The limits
        due to these causes
           are only transitory,
      and can be overcome
          by the progress
              of perception
                 and thinking.

    [11] Dualism
        makes the mistake
           of transferring
               the antithesis
                  of object
                     and subject,
       which
          has
        meaning only
           within the perceptual realm,
       to purely notional entities
           outside this realm.

    But
         since
             the separate things
                within the perceptual field
                   remain
                  separated only so long
           as the perceiver
              refrains
                 from thinking
        (which
            cancels all separation
                and shows it
                   to be
                      due to purely subjective factors),
           the dualist
              is therefore transferring
                 to entities
                    behind the perceptible realm
                       determining
                    factors
             which
                even for this realm
              have no absolute validity,
           but only relative.

    He
         thus splits
            up the two
               factors
        concerned
           in the cognitive process,
       namely percept
           and concept,
       into four:
           (1) the object
               in itself;
           (2) the precept
              which the subject
                 has of the object;
           (3) the subject;
              (4) the concept
          which relates
             the precept
           to the object
               in itself.

    The relation
        between subject
           and object
         is
       a real one;
          the subject
         is really
       (dynamically)
          influenced by the object.

    This real process
        is said not
           to appear in consciousness.

    But it
          is supposed to evoke
             in the subject a response
           to the stimulation
               from the object.

    The result of this response
          is said
             to be the percept.

    Only at this stage
        does it
           enter our consciousness.

    The object
        is said
           to have an objective
        (independent
           of the subject)
              reality,
       the percept
           a subjective reality.

    This subjective reality
          is referred
             by the subject to the object.

    This reference
        is called
           an ideal one.

    With this
          the dualist
              therefore splits
                 up the cognitive process
                    into two parts.

    The one part,
       namely,
          the production
             of the perceptual object
                out of the thing-in-itself,
       he conceives of
           as taking place
              outside consciousness,
       whereas the other,
          the combination
             of percept
                with concept
                   and the reference
                      of the concept
                         to the object,
       takes place,
          according to him,
       within consciousness.

    With these presuppositions,
       it is
          clear
         why
             the dualist
                believes
               his concepts
              to be merely
                   subjective representatives
           of what
              is there prior to
          his consciousness.

    The objectively real process
        in the subject
            by means
      of which
         the percept
            comes about,
      and still more
          the objective relations
              between things-in-themselves,
      remain
          for such a dualist inaccessible
             to direct knowledge;
      according to him,
         man can obtain only
            conceptual representatives
               of the objectively real.

    The bond of unity
         which connects things
            with one another
               and
          also
         objectively with the individual mind
            of each
               of us (as thing-in-itself) lies
                   beyond our consciousness
                       in a being-in-itself
                           of whom,
                              once more,
                           we can have
                              in our consciousness merely
               a conceptual representative.
 
    [12] The dualist
        believes
           that
              he would dissolve away
                 the whole world
           into a mere abstract. scheme
               of concepts,
       did
          he not insist
             on real connections
                between the objects
          besides
             the conceptual ones.

    In other words,
       the ideal principles
          which
             thinking
            discovers seem too airy
           for the dualist,
              and
         he seeks,
            in addition,
       real principles
          with which
             to support them.
 
    [13] Let us examine
        these real principles
            a little more closely.

    The naive man
          (naive realist)
             regards the objects
           of external experience
               as realities.

    The fact that his hands
          can grasp these objects,
       and
          his eyes
              see them,
       is for him
           sufficient proof
               of their reality.

    "Nothing
        exists
           that cannot be perceived"
       is,
          in fact,
       the first axiom
           of the naïve man;
       and
          it is held
             to be equally
                valid
           in its converse:
        "Everything
           which can be perceived exists."

    The best evidence
        for this assertion
           is
      the naïve man's belief
         in immortality
            and ghosts.

    He thinks
        of the soul
            as refined material
      substance
         which may,
        in special circumstances,
       become visible
           even to the ordinary man
        (naive belief
           in ghosts).
 
    [14] In contrast
        with this
            real world
                of his,
      the naïve realist
         regards everything else,
      especially
          the world
              of ideas,
      as unreal
          or
              "merely ideal".

    What
         we add
            to objects
               by thinking
                  is
              nothing
                 more than thoughts
               about the things.

    Thought adds nothing real
        to the percept.
 
    [15] But it is not only
        with reference
           to the existence
              of things
      that the naïve man
         regards
            sense
               perception as the sole proof
            of reality,
      but
         also with
            reference
               to events.

    A thing,
       according to him,
          can act
             on another
          only
              when a force
                  actually present to sense
                      perception issues
           from the one and
              seizes
                 upon the other.

    In the older physics
         it was thought
             that very fine substances emanate
           from the objects
              and penetrate
                 through the sense organs
                    into the soul.

    The actual
          seeing
             of these substances
            is impossible
          only
         because
            of the coarseness
               of our sense organs relative
                   to the fineness
                       of these substances.

    In principle,
       the reason
           for attributing reality
               to these substances
                  was the same
         as for attributing it
            to the objects
               of the sense-perceptible world,
       namely
          because
             of their mode
                of existence,
       which
          was thought
             to be
                analogous
           to
              that
                 of sense-perceptible reality.
 
    [16] The self-contained nature of what
          can be experienced
             through ideas
            is not regarded
           by the naïve mind
         as being real
            in the same way
               that sense experience is.

    An object grasped
        in
       "mere idea"
          is regarded
              as a chimera
            until
                conviction of its reality
                   can be given
                  through sense perception.

    In short,
       the naïve man
          demands
             the real evidence
           of his senses
               in addition
                   to the ideal evidence
                       of his thinking.

    In this need
        of the naïve man
           lies the original ground
              for primitive forms
                 of the belief
                    in revelation.

    The God
         who is given
              through thinking
                 remains
           to the naïve mind
          always a merely "notional" God.

    The naïve mind
        demands
           a manifestation
              that is accessible
           to sense perception.

    God must appear
        in the flesh,
       and
          little value
             is attached
           to the testimony
               of thinking,
       but
          only to proof
             of divinity
                such as changing
                   water
           into wine
               in a way
              that can be testified
                 by the senses.

    [17] Even cognition
        itself
       is pictured
          by the naïve man
              as a process analogous
                  to sense perception.

    Things,
       it is thought,
          make an impression
             on the soul,
       or send
           out images
         which
            enter through our senses,
       and so on.
 
    [18] What the naïve man
        can perceive
           with his senses
          he regards as real,
       and
          what
             he cannot thus
                  perceive
        (God,
           soul,
              cognition, etc.)
           he regards
               as analogous
                  to what he
                does perceive.
 
    [19] A science
        based
           on naïve
              realism
                 would have
               to be nothing
         but an exact description
            of the content
               of perception.

    For naïve realism,
       concepts
          are only
             the means
           to an end.

    They exist
        to provide
           ideal counterparts
              of percepts,
       and have no significance
           for the things themselves.

    For the naïve realist,
       only the individual tulips
          which
         he sees (or could see) are real;
       the single idea
          of the tulip
             is to him an abstraction,
       the unreal thought-picture which
           the soul
        has put together
           out of the characteristics common
               to all tulips.
 
    [20] Naive realism,
       with its fundamental principle
           of the reality
               of all perceived things,
       is contradicted
           by experience,
       which
          teaches us
             that the content of percepts
                is of a transitory nature.

    The tulip I see
        is real today;
       in a year
          it will have vanished
             into nothingness.

    What persists
        is
           the species tulip.

    For the naïve realist,
       however,
          this species
        is "only"
           an idea,
       not a reality.

    Thus
         this theory
            of the world
               find itself
           in the position
               of seeing
                   its realities
                arise and perish,
       while
          what
             it regards
           as unreal,
       in contrast
           with the real,
       persists.

    Hence naïve realism
        is compelled
           to acknowledge,
       in addition
           to percepts,
       the existence
           of something ideal.

    It must admit
          entities
              which
                 cannot be perceived
               by the senses.

    In doing so,
       it justifies itself
           by conceiving
               their existence
         as being analogous
            to
               that
                  of sense-perceptible
                objects.

    Just
         such hypothetical realities
            are
               the invisible forces
           by means
         of which
             the sense-perceptible objects
                  act
           on one another.

    Another
          such thing
              is heredity,
       which
          works on
             beyond the individual
            and is the reason
         why a new
            being
               which
                  develops
                     from the individual
                    is similar
           to it,
       thereby serving
           to maintain the species.

    Such
         a thing
            again is
           the life-principle
              permeating
          the organic body,
       the soul
          for which the naïve mind
             always finds
                a concept formed
           in analogy
               with sense realities,
       and finally
           the naïve man's Divine Being.

    This Divine Being
        is thought of
           as acting
              in a manner
            exactly corresponding
           to the way
         in which man himself
            is seen to act;
       that is,
          anthropomorphically.
 
    [21] Modern physics
        traces
           sensations
              back
           to processes
              of the smallest particles
                 of bodies
                    and of
                       an infinitely fine substance,
                   called ether,
                      or
                         to other such things.

    For example,
       what
          we experience
             as warmth is,
       within the space occupied
           by the warmth-giving body,
       the movement
           of its parts.

    Here
         again
            something imperceptible
               is conceived
           in analogy
               with what
                  is perceptible.

    In this sense,
       the perceptual analogue
          to the concept "body"
        would be,
           shall
         we say,
            the interior
               of a totally enclosed space,
           in which elastic
        spheres
           are moving
              in all directions,
           impinging one
              on another,
           bouncing
              on and off the walls,
       and so on.
 
    [22] Without such assumptions the world
        would fall apart
           for the naïve realist
               into an incoherent aggregate
                   of percepts
                       without mutual relationships
                           and with no
           tendency
          to unite.

    It is clear,
       however,
          that naïve realism
        can make
           these assumptions
              only by an inconsistency.

    If
         it would remain true
            to its fundamental principle
         that only
            what is perceived
               is real,
       then
          it ought not
             to assume
           a reality
         where
             it perceives nothing.

    The imperceptible forces
         which
            proceed
           from the perceptible things
              are
                 in fact
                unjustified hypotheses
           from the standpoint
               of naïve realism.

    And
         because
             naïve realism knows
                no other realities,
       it invests
          its hypothetical forces
             with perceptual content.

    It thus
        ascribes
           a form
              of existence
        (perceptible existence)
           to a sphere
              where the only means
                 of making any assertion
                    about such existence,
                   namely,
                      sense perception,
       is lacking.
 
    [23] This self-contradictory theory
        leads
           to metaphysical realism.

    This constructs,
       in addition
           to the perceptible reality,
       an imperceptible reality
          which
             it conceives
                on the analogy
                   of the perceptible one.

    Therefore
         metaphysical realism is
            of necessity dualistic.
 
    [24] Wherever the metaphysical realist observes
        a relationship
           between perceptible things
       (such as when
            two things
         move towards each other,
            or
               when
              something objective
                 enters
             consciousness),
          there
             he sees a reality.

    However,
       the relationship
          which
             he notices
                can only be expressed
           by means
               of thinking;
           it cannot be perceived.

    The purely ideal relationship
        is
           then arbitrarily made
              into something similar
                 to a perceptible one.

    Thus,
       according to this theory,
          the real world
        is composed
           of the objects
               of perception
              which are in ceaseless flux,
       arising and disappearing,
          and
             of imperceptible forces
         which
              produce the objects
           of perception,
       and are
          the things that endure.
 
    [25] Metaphysical realism
        is a contradictory mixture
           of naïve realism
               and idealism.

    Its hypothetical forces
        are
           imperceptible entities
              endowed
           with the qualities
               of percepts.

    The metaphysical realist
        has made
           up his mind to acknowledge,
       in addition
           to the sphere
         which he
            is able
               to know
                  through perception,
       another sphere
          for which
             this means
                of knowledge
                   fails him
               and
             which
                can be known only
               by means of thinking.

    But
         he cannot make
            up his mind
               at the same time
              to acknowledge
         that the mode
            of existence
               which
                  thinking reveals,
                     namely,
                   the concept (idea),
       is just
           as important
               a factor
                   as the percept.

    If we
        are
           to avoid
          the contradiction
             of imperceptible percepts,
       we must admit that
           the relationships
         which
            thinking
               establishes
                  between the percepts
                can have
               no other mode
           of existence
               for us
                  than
                     that
                        of concepts.

    If
         we reject the untenable part
            of metaphysical realism,
       the world
          presents itself
             to us
                as the sum
                   of percepts
                       and their conceptual (ideal) relationships.

    Metaphysical realism
        would
           then
         merge
            into a view of the world
               which
                  requires
               the principle
                  of perceivability
                     for percepts and
             that
                of conceivability
                   for the relationships
                       between the percepts.

    This view of the world
          can admit no third sphere
       -- in addition
           to the world
               of percepts
                   and the world
                       of concepts --
             in which
                 both
                     the so-called "real"
                         and
                            "ideal" principles are simultaneously valid.

    [26] When the metaphysical realist
          asserts that,
       besides
           the ideal relationship
              between the percept
                 of the object
                    and the percept
                       of the subject,
       there must also exist
           a real relationship
              between the "thing-in-itself"
                 of the percept
                    and the "thing-in-itself"
                       of the perceptible subject
        (that is,
           of the so-called individual spirit),
              he is basing his assertion
                 on the false assumption
                    of a real process,
           analogous
               to the processes
                   in the sense world
             but imperceptible.

    Further,
       when the metaphysical realist
          asserts
             that
                we
               enter
                  into a conscious ideal
                     relationship
                   to our world
                       of percepts,
       but
          that
         to the real world
            we can have only
               a dynamic (force) relationship,
       he repeats the mistake
          we have already criticized.

    One can talk
        of a dynamic relationship
            only within the world
                of percepts
       (in the sphere
          of the sense
              of touch),
          but
             not outside that world.
 
    [27] Let us call the view
         which we
              have characterized above,
       into which metaphysical realism
          merges
             when
                 it discards its contradictory elements,
                    monism,
                   because
                      it combines
           one-sided realism
              with idealism
                 into a higher unity.
 
    [28] For naïve realism,
       the real world
          is
             an aggregate
           of perceived
              objects (percepts);
       for metaphysical realism,
          not only
         percepts
             but also imperceptible forces
                are real;
       monism
          replaces
        forces
           by ideal connections
         which
            are gained
               through thinking.

    The laws of nature
          are just such connections.

    A law of nature
        is
           in fact nothing
         but the conceptual expression
            of the connection
               between certain percepts.
 
    [29] Monism
        never finds it necessary
           to ask
              for any principles
                 of explanation
                    for reality other
                  than percepts
                     and concepts.

    It knows
          that
         in the whole field
            of reality
               there is
              no
        occasion
           for this question.

    In the perceptual world,
       as it presents itself directly
           to perception,
       it sees one half
           of the reality;
       in the union
           of this world
              with the world
                 of concepts
              it finds the full reality.

    The metaphysical realist
        may object
           to the adherent
              of monism:
       It may be
          that
         for your organization,
       your cognition
          is
        complete
           in itself,
       with no
          part lacking;
       but you
          do not know how
              the world
        is
             mirrored in an intelligence
                organized differently
               from your own.

    To this
         the monist
            will reply:
       If there are intelligences other
          than human,
       and
          if
             their percepts
                are different
           from ours,
       all that concerns me
          is
         what reaches me
            from them
               through perception
                   and concept.

    Through my perceiving,
       that is,
           through this
               specifically human mode
                  of perceiving,
               I,
                  as subject,
               am confronted
                  with the object.

    The connection of things
        is thereby interrupted.

    The subject
        restores this connection
           by means of thinking.

    In doing so
         it puts itself
              back
           into the context
               of the world
                   as a whole.

    Since it
        is only through
           the subject that the whole
              appears
                  cut
           in two
              at the place
                 between our percept
                    and our concept,
       the uniting
           of those two
              gives us
          true cognition.

    For beings
        with a different perceptual world
       (for example,
          if they
             had twice our number
                of sense organs),
          the continuum
             would appear
                broken
              in another place,
          and the reconstruction
             would accordingly have
                to take
                   a form specific
              for such beings.

    The question
          concerning
              the limits
                 to cognition
                exists only
           for naïve
               and metaphysical realism,
       both
          of which
              see
           in the contents
               of the soul
          only an ideal representation
             of the real world.

    For these theories,
       what exists
           outside the subject
              is
           something absolute,
              founded
                 in itself,
           and
         what is contained
            within the subject
               is a picture
           of this absolute,
       but
          quite external
             to it.

    The completeness
        of the cognition
           depends
        on the greater
           or lesser degree
              of resemblance
                 between the picture
                    and the absolute object.

    A being
        with fewer senses
       than man
          will perceive less
             of the world,
      one with more senses
         will perceive more.

    The former
        will accordingly have
           a less complete knowledge
          than the latter.
 
    [30] For monism,
       the situation
          is different.

    The manner
         in which
             the world continuum
            appears
               to be rent asunder
           into subject
              and object
            depends
           on the organization
               of the perceiving being.

    The object
        is not absolute,
           but merely relative,
       with reference
           to this particular subject.

    Bridging
        over the antithesis,
           therefore,
        can again take place only
           in the quite specific way
         that is characteristic
            of the particular human
           subject.

    As soon
        as the I,
       which
          is separated
             from the world
                in the act
                   of perceiving,
       fits itself
          back
         into the world continuum through
            thoughtful contemplation,
       all further questioning
          ceases,
       having been
          but a consequence
             of the separation.
 
    [31] A differently constituted
        being
           would have
          a differently constituted cognition.

    Our own cognition
        suffices
           to answer
          the questions
              put
           by our own nature.
 
    [32] Metaphysical realism
        has to ask:
       By
          what means
             are our percepts given?

    What is it
        that affects the subject?
 
    [33] Monism
        holds
             that percepts
                are determined through the subject.

    But
         at the same time,
       the subject
          has
             in thinking
                the means
           for canceling
               this self-produced determination.
 
    [34] The metaphysical realist
        is faced
           by a further difficulty
         when
             he seeks to explain
                the similarity between the world
                   pictures
               of different human individuals.

    He has
          to ask himself:
       How is it
          that the picture
             of the world
                which
              I build up
                 out of my subjectively determined
                    percepts
                       and my concepts
                turns out
                   to be
                      the same
               as the one
                  which
                     another individual
                    is also building up
                   out of the same
                       two subjective factors?

    How can I,
       in any case,
          draw conclusions
             from my own
                subjective picture
                   of the world
                      about
         that
            of another human being?

    The fact that people
        can understand
           and get on
              with one another
                 in practical life
                leads
              the metaphysical realist to conclude
                 that their subjective world pictures
                    must be similar.

    From the similarity
        of these world pictures
       he
         then further concludes
       that the
       "individual spirits"
          behind the single human subjects
              as percepts,
          or the "I-in-itself"
              behind the subjects,
          must also be like
              one another.

    [35] This
        is an inference
           from a sum
               of effects
                  to the character
                     of the underlying causes.

    We believe that
         we can understand
            the situation well enough
           from a sufficiently large number
               of instances
              to know how
          the inferred
             causes
            will behave
               in other instances.

    Such an inference
          is called an inductive inference.

    We shall be obliged
          to modify
             its results
                if further observation
                   yields some unexpected element,
       because
          the character
             of our conclusion is,
                after all,
               determined only
                  by the particular form
               of our actual observations.

    The metaphysical realist
        asserts
           that this knowledge
              of causes,
           though conditional,
       is nevertheless quite sufficient
           for practical life.
 
    [36] Inductive inference
        is
           the method underlying
              modern metaphysical
           realism.

    At one time
          it was thought that
         we could evolve
            something
           out of concepts
              that is
                 no longer
                    a concept.

    It was thought
          that the metaphysical realities,
       which metaphysical realism
          after all requires,
       could be known
           by means
              of concepts.

    This kind
        of philosophizing
       is now out of date.

    Instead
          it
              is thought
                  that one can infer
           from a sufficiently large number
               of perceptual facts
              the character
                 of the thing-in-itself which
                    underlies these facts.

    Whereas formerly
          it was from concepts,
       now
          it is from percepts
             that people
                seek to evolve
           the metaphysical.

    Since
         one has concepts
            before oneself
               in transparent clearness,
       it was thought
          that one
             might be able
                to deduce
                   the metaphysical
               from them
                   with absolute certainty.

    Percepts
        are not given
           with the same transparent clearness.

    Each subsequent one
        is a little different
           from others
               of the same kind which
                   preceded it.

    Basically,
       therefore,
          anything
        inferred from
           past percepts
              will be somewhat modified
                 by each subsequent percept.

    The character
        of the metaphysical thus
            obtained can,
        therefore,
           be only relatively true,
      since it
         is subject to correction
            by further instances.

    Eduard von Hartmann's metaphysics has
        a character determined
           by this basic method,
      as expressed
          in the motto
              on the title page
                  of his first important book:
       "Speculative
           results
              following
         the inductive method
            of Natural Science."
 
    [37] The form
         which the metaphysical realist
            nowadays gives to his things-in-themselves
               is obtained
                  by inductive inferences.

    Through considerations
        of the process
            of cognition
           he is convinced
              of the existence
                 of an objectively
                    real world continuum,
      over
         and above
            the "subjective" world continuum
        which is cognizable
           through percepts
              and concepts.

    The nature
        of this reality
       he thinks
          he can determine
             by inductive inferences
                from his percepts.
 
    Author's addition,
       1918

 
    [1] For
         the unprejudiced observation
            of what
               is experienced
           through percept
               and concept,
       as we
          have tried
             to describe
                it
           in the foregoing pages,
       certain ideas
          which
         originate
            in the field
               of natural science
             are repeatedly found
                to be disturbing.

    Thus it
        is said
           that
         in the spectrum
            of light
               the eye
                  perceives
                     colors
               from red
                  to violet.

    But
         in the space
            beyond the violet
               there are
                  forces
               of radiation
         for which
            there is
               no corresponding color-perception
           in the eye,
       but instead
           there is a definite chemical
          effect;
       in the same way,
          beyond the limit
             of the red
            there are radiations
               having only
          an effect
             of warmth.

    By studying
          these and other similar phenomena,
       one is led
           to the view
              that
                 the range
                    of man's perceptual world
                  is determined
                     by the range
                        of his senses,
       and
          that
             he would be confronted
                by a very different world
         if he
            had additional,
               or altogether different,
       senses.

    Anyone who
        chooses
           to indulge
              in the extravagant flights
                 of fancy
         for which
            the brilliant discoveries
               of recent scientific research offer
                  such tempting opportunities,
       may well arrive
           at the conclusion
              that nothing
                 enters man's field
               of observation except
         what can affect
            the senses
               which
                  his bodily organization
                     has evolved.

    He has no
        right to regard
           what is perceived,
       limited
          as it
             is
           by his organization,
       as in any way
          setting
             a standard
           for reality.

    Every new sense
        would confront him
           with a different picture
               of reality.
 
    [2] Within its
         proper limits this view
            is entirely justified.

    But
         if
             anyone allows
                this view
              to confuse him
           in his unprejudiced observation
               of the relationship
                   of percept
                       and concept
                          as set out
                       in these chapters,
       then
          he will bar
             his own way
           to any realistic knowledge
               of man
                   and of the world.

    To experience
          the essential nature
             of thinking,
       that is,
          to work
              one's way
           into the world
               of concepts
                   through one's own activity,
       is an entirely different thing
           from experiencing something perceptible
               through the senses.

    Whatever senses man
        might possibly have,
       not
          one would give him
             reality
          if his thinking
              did not permeate with concepts
         whatever
            he perceived
           by means
              of it.

    And every sense,
       however constructed,
          would,
             if thus permeated,
       enable him
          to live within reality.

    This question
        of
           how
              he stands
            in the world
                of reality
       is untouched by any speculations
      he may have
         as to
            how
               the perceptual world might appear
            to him
       if he had different senses.

    We must clearly understand
          that every perceptual picture
             of the world
            owes its form
           to the organization
               of the perceiving being,
       but
          also that the perceptual picture
         which
            has been thoroughly permeated
           by the experience
               of thinking
                  leads us
                     into reality.

    What causes us
          to enquire into our relationship
             to the world
            is not
          the fanciful pictures
             of how different
                the world
                   would appear
           to other
          than human
             senses,
       but
          the realization
             that every percept
                gives us only
           a part
              of the reality concealed
                 within it,
               in other words,
                  that it
          directs us away
             from its inherent reality.

    Added to this
        is
           the further realization that thinking
              leads us
           into that part
               of the reality
         which the percept
            conceals within itself.

    [3] Another difficulty
        in the way
            of the unprejudiced observation
                of the relationship
                    between the percept
                        and
                      the concept
                         wrought
                        by thinking,
                           as here described,
                        arises when,
                           for example,
                        in the field
                           of experimental physics
          it becomes necessary
       to speak not
          of immediately perceptible elements,
      but
         of non-perceptible quantities
        as in the case
           of lines
              of electric or magnetic force.

    It may seem
         as if the elements
            of reality
               of which
                  physicists
                      speak
                    had
                       no
                          connection either
                             with what
                            is perceptible
                           or
               with the concepts
                   which active thinking
                has wrought.

    Yet
         such
             a view
                would be based
               on self-deception.

    The main point
        is that all
           the results
               of physical research,
       apart from unjustifiable hypotheses
          which ought to be excluded,
       have been obtained
           through percept
               and concept.

    Elements
         which are seemingly non-perceptible
            are placed
           by the physicist's sound instinct
               for knowledge
                   into the field
         where
             percepts lie,
       and
          they are thought of
             in terms
           of concepts
              commonly used
                 in this field.

    The strengths
        of electric or magnetic fields
            and such like
           are arrived at,
      in the very nature
          of things,
      by no
         other
             process
          of knowledge
         than the one
        which
           occurs
          between percept
              and concept.
 
    [4] An increase
         or a modification
            of human senses
          would yield
              a different perceptual picture,
       an enrichment or a modification
           of human experience.

    But
         even with this experience
             one could arrive
           at real knowledge
               only through the interplay
                   of concept and percept.

    The deepening
        of knowledge
           depends
        on the powers
            of intuition
      which
           express themselves
        in thinking
       (see Chapter 5).

    In the living
          experience
         which
            develops
           within thinking,
       this intuition
          may dive down
             to greater
                or to lesser depths
           of reality.

    An extension
        of the perceptual picture
           may provide
          stimulation
             for this
        diving down
           of intuition,
       and thus
          indirectly promote it.

    But
         under no
            circumstances should this diving
           into the depths
               to reach
                  reality
                      be confused
                   with being confronted
               by a perceptual picture
                   of greater or lesser breadth,
       which
          in any case
             can only contain half
                the reality,
       as determined
           by the organization
               of the cognizing being.

    If
         one does not lose oneself
            in abstractions,
       one will realize
          that
         for a knowledge
            of human nature
               it is
                  a relevant fact
                     that in physics
                         one has to infer
                            the existence
               of elements
                   in the perceptual field
         for which
             no sense organ is tuned
                as it
                   is
               for color or sound.

    Man's being,
       quite concretely,
          is determined not
             only by what
          his organization presents
             to him
                as immediate percept,
       but
          also by the fact
             that
                from this immediate
                   perception other things
                are excluded.

    Just
         as it
            is necessary
               for life
              that
                 in addition
                    to the conscious waking state
                  there should be
                      an unconscious sleeping state,
       so for man's experience
           of himself
              it is necessary
         that
            in addition
           to the sphere
               of his sense
              perception
                  there should be another sphere
       -- in fact
           a far larger one --
              of elements not perceptible
                   to the senses
                  but belonging
                     to the same field
                   from which
                      the sense
                         percepts come.

    All this was already implied
        in the original presentation
            of this work.

    The author
        adds these extensions
           to the argument
          because he
              has found by experience
          that many a reader
              has not read accurately enough.
 
    [5] It is
          to be remembered, too,
       that
          the idea of percept
             developed
           in this book
        is not
           to be confused
              with the idea
                 of external sense
             percept
         which
            is
         but a special instance
            of it.

    The reader
        will gather
           from what
          has gone before,
       but even more
           from what
              will follow,
       that "percept"
          is
             here taken to be
                everything that approaches man
               through the senses
                   or through the spirit,
       before it
          has been grasped
             by the actively elaborated concept.

    "Senses",
       as
          we ordinarily understand the term,
       are not necessary
           in order to have percepts
              in soul-
                 or spirit-experience.

    It might be said
         that this
            extension of our ordinary usage
               is not permissible.

    But
         such extension
            is absolutely necessary
         if we
            are not
          to be prevented
             by the current sense
                of a word
                   from enlarging
                  our knowledge
                     in certain fields.

    Anyone
         who uses "perception"
            to mean
          only
        "sense perception"
           will never arrive
               at a concept fit
                   for the purposes
                       of knowledge
       -- even knowledge
           of this same sense perception.

    One must sometimes enlarge
        a concept
       in order that
           it may get
              its appropriate meaning
            in a narrower field.

    Sometimes
         one must also add
            to the original content
               of a concept
          in order that
             the original concept
                may be justified
               or,
                  perhaps,
               readjusted.

    Thus
         we find it
             said here
                in this book
        (see Chapter 6):
            "The mental picture
                is
              an individualized concept."

    It has been objected
          that this
             is an unusual use
           of words.

    But
         this use
            is necessary
         if we
            are
          to find out
         what
             a mental picture
                really is.

    How can
          we expect any progress
             in knowledge
          if
             everyone who finds himself
                compelled
               to readjust
             concepts
        is to be met
           by the objection,
        "This
            is an unusual use
               of words"?