Preproceedings 2006 - Austrian Ludwig Wittgenstein Society

experience gives an epistemologically significant status to
a single observation. If perception does not depend on an
observer’s mental states, then any persons can make an
observation, and “on the basic of a single experience, a
number of verbal statements are justified” (Russell, 1997,
21). A single observation can be used for the confirmation
and verification of a whole series of statements. These
sentences are the foundation of all scientific knowledge,
and their truth values are established by means of
sensuous perception.
Perception provided the meaning of names and
allowed establishing the truth values of propositions. In the
philosophy of language observation was used in two ways:
first, as the initial period of the language learning, which
necessarily included ostension (Kripke, 1980); second, to
ascribe meaning to some names of the physical objects. In
language some names and predicates applicable to the
physical objects receive their meaning through a material
process involving ostension. Hence, language learning
and linguistic competence are a matter of grasping the
sense of words.
The sensuous perceptions were assumed to
correspond exactly to reality, so sense organs provided
adequate cognition of the objective world. Perception
understood as passive provided a possibility of reliable
and adequate cognition of the world. On the whole,
perceptionaccounted for as a representation of reality
provided both an ontological and epistemological
foundation of objectivism: people did not doubt the
existence of the external world and its cognizability. The
most serious difficulty of this philosophical approach is
David Hume’s problem of induction: how can we justify our
belief in existing of the external world if we only have
sensations.
As we can see, perception that is free from the
distorting mind’s influence played a significant role in
philosophy, namely, in providing adefinition for the basic
philosophical conceptions, such as object, sense,
meaning, truth of a sentence.
4. If perception is active
Since the 1980s the view in psychology that perception is
involved in the active gathering of information prevails.
This activity reveals itself not only on an external muscular
level, but also in the processing of the information received
by the brain from neurons, in building an integral image
based on it and in the management of the perceiver’s
further activity. That the experience-ordering structures
carry out such actions as classification and categorization
of the outer stimuli – actions traditionally referred to as
“theoretical” or mental – provides a basis for the claim that
any experience is theory laden. Moreover, theory
ladenness appears to be a necessary condition of
perception, because any perception is possible only due to
processing and categorization. Besides, theory-ladenness
plays an important role – giving meaning to the perceived.
Previous experience forms different expectation
activating different structures even in the same situation. It
leads to the difference in understanding of situation and
hence different observers can interpret the same situation
in various senses. These fluctuations of sense deprive a
single observation of its epistemological status. “Protocol
sentences” cannot have cognitive value and could not be
used for justification of the theoretical statement. Instead
of singular observation we should admit the reproducibility
of observation. (For a detailed analysis see Radder, 1996.)
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Two Viewpoints On Perception: Possibility of Dialog - Anna Storozhuk
That observations and experiments cannot be
reproduced by any person or in any condition should not
be a pretext for rejecting this requirement. Iterated
experiments play a role in elaboration, allowing us to
gather more detailed information about a situation. Only a
set of several repetitions of the experiment can have the
status of a scientific fact, which has epistemological value
– because it has integrated in itself a whole series of
observations. Thus the scientific fact is a subject of
historical development. (Fleck, 1979 (1935))
Since the meaning of a statement is connected to its
truth value, Tarski believed that the concept of truth could
not be correctly defined in a natural language due to its
fuzziness and developed the definition of truth for the
formal languages.
The same expression can, in one language, be a true
statement, in another a false one or a meaningless
expression. There will be no question at all here of
giving a single general definition of the term. The
problem which interests us will be split into a series of
separate problems each relating to a single language.
(Tarski, 1956 (1936) (1935), 153)
To avoid relativity concerning the sense and truth
value of a statement Duhem and Quine formulated the
thesis that “our statements about the external world face
the tribunal of sense experience not individually but only
as a corporate body”. (Quine, 1951, 38)
Since perception is the active collecting of such
information that may correspond to expectations, the same
situation may be perceived by various observers
differently, and perception itself depends on the past
experience of the observers. To give an example I refer to
Hanson’s consideration of two microbiologists who see
Amoeba through a microscope and have distinct visions
because “one sees a one-celled animal, the other a noncelled
animal” (Hanson, 1958, 4).
As appears from the above the ostensive definitions
are undetermined, since the finding of relevant information
is determined by the former experience of a subject. For
the first time the result was formulated by Quine: “pointing
does not tell us which summation of momentary objects is
intended, beyond the fact that the momentary object of
hand is to be in the desired summations”. (Quine, 1950,
622)
The environment is, as a rule, sufficiently
sophisticated to support more than one perception
hypothesis. Different observers, even if they are both
experienced, may confirm exactly opposite hypotheses
while perceiving the same situation. One and the same
situation can be perceived divergently because of the
difference in expectations formulated by dissimilar
theoretical dispositions. A scientific theory and the
background knowledge influence perception through the
special features in the structure of the perceptual scheme
and the selected activation of some of them.
As an observer actively collects information
confirming his hypothesis, he unconsciously ignores any
counterexamples. If facts exist contrary to accepted beliefs
– so much the worse for the facts: they will be ignored. The
point was formulated by Peter Galison [1987], where he
cites many examples which illustrated how theoretical
presuppositions of the experimenters may enter into the
decision to end an experiment and report the result.
Galison's view is that experiments end when the
experimenters believe that they have a result that will
stand up in court.