This paper is an attempt to answer one of the most fundamental
questions of philosophy through an analysis of the writings of A.J.
Ayer, R.Chisholm, L. Wittgenstein and the theories of Moore and
Descartes.
WHAT IS KNOWLEDGE AND HOW DO WE KNOW THINGS ?
Epistemology or the Theory of Knowledge is an area of
philosophical inquiry that began with the ancient Greeks and has
intruded upon the present, still unresolved Perhaps, the two most
famous and divergent, schools of epistemology are those of Descartes
and the so called "Sceptics".
Descarte's construction of the universe can be summarized by
one of the most popular propositions to ever come out of
philosophy, namely "I think threfore I am." This is an interesting
hypothesis but, it does leave some very important questions unanswered
as we shall see later.
The Sceptics viewpoint on epistemology as well as the universe
as a whole has a number of formulations that range from the severe to
the unsatisfying. The most common formulation is as follows:
"I may for all I know be dreaming". Given that one accepts this thesis,
one is therupon presented with very powerful grounds for doubting
things that appear manifest.
Both of the above formulations serve as cornerstones for
current epistemology.They are used in conjunction with the fundamental
questions in the Theory of knowledge to develop more cohesive and
complete epistemological constructions. The questions which any
reasonable theory must adress include the following:
1. What, if any, is the distinction between knowledge and true
opinion?
2. How does the concept of evidence relate to knowledge about
a proposition ?
3. What is the difference between a proposition that is
self-evident and one that is empirically derived?
4. How does the truth value of a proposition realte to ones
knowledge of that statement.
A.J. Ayer in his "The Problem of Knowledge" seems to provide a
good first foundation in his approach to epistemology. He firstly,
differentiates between the Theory of Knowledge and the areas of
Lexicography and Scientific inquiry. Epistemology one must remember
ius neutral with respect to particular matters of fact unlike
scientific inquiry. It is neither proved by formal demonstration as in
mathematics nor is it tested by observation as in mathematics.
Epistemology is simply an analysis and clarification of
propositions or families of propositions. The manner in which Ayer
wishes us to analyzes propositons can be thought of in this manner:
"A" knows a proposition "p" if and only if
1. "A" has true belief of "p"
2. "A" has the right to be sure that "p"
Where "2" above is defined as:
1. "p" is self-evident
2. "p" is warranted by experience
3. "p" follows from other things of which we have the right to
be sure.
This seems at first glance to be a reasonable formulation of
what we "know", but how does it stand up to more rigorous testing.
Scepticism, being the bane of most philosophies should be dealt with
first. Consider, two forms of the sceptical hypothesis, the so-called
"strong" and "weak" forms:
Strong form: For all you know, for all p (you think you know)
you don'y know p
Weak form: For all p, for all you know, you don't know p.
The "strong form" of the sceptical hypothesis is equivalent to
stating that "all x is illusory". This is in fact problematic. If all
x is illusory then all x can not be illusory because there can be no
concept of a true perception of x.
Ayer's theory hence, has only to deal with the "weak form" of
the sceptical hypothesis. Even the weak from should produce grounds
for doubting Ayer's thesis, especially in the case of something that
is warranted by experience. Ayer grants that scepticism is right for
a class N pf propositions where this class is all "p" outside the set
of "directly warranted propositions". In other words he disputes the
weak form of the sceptical hypothesis and creates an even weaker
sceptical hypothesis of the form: "For all "p" outside the "directly
warranted" for all you know you don't in actuality know it ."
In short Ayer's method of analysis includes a case by case
consideration of each proposition as it appears to him and a similar
refutation of the sceptic.
Chisolm in his "Theory of Knowledge" takes another attitude in
dealing with epistemology and the ever present sceptic. He begins by
assuming three statements. Firstly, there actually exists something we
know and furthemore that which we know is fairly equivalent to the
class of propositions we think we know. Secondly, our knowledge of "p"
is justified by evidence for "p". Finally, that there exist sets of
principles that govern our use of evidence and our justification for
concluding "p".
Chisolm further, goes on to state that what we know about the
universe is actually a hierarchy of propositions, where a set of
propositions act as evidence for another. This hierarchy uses as its
basis a certain class of propositions that are to be considered
"directly evident". That is just the class of propositions "p" for
which the following is true:
"What justifies me in thinking that a is F is just the fact
that a is F"
Chisolm's weakness comwes in his response to the sceptical
hypothesis. He manages to deal with the sceptic by ignoring him (in a
sense). The sceptic would ask Chisolm "How do you know that believing
that all men are mortal is self-presenting (hence directly evident).
Chisolm's response is , "I know that believing that all men are mortal
is self-presenting." This manner of dealing with the sceptic may leave
a bit to be desired.
Chisolm's major contribution though is a theory of how we come
to believe things. In this he does manage to put the sceptic to rest.
Chisolm's formulation is as follows. If it is not the case that
witholding belief of a proposition "h" is more reasonable than
believing "h" then believing "h" is more reasonable than believing
"not h". From this thesis, one should believe "h" just in case the
degree of reasonableness of believing "h" is greater than 1-e where e
is a measure of the degree of caution for that proposition.
Chisolm thus contrasts Ayer's thesis in that knowledge does
not have to be "True belief" it just has to be believable "beyond a
reasonable doubt". Take a situation for example where the correct
anser is "X" most of the evidence suggests "Y" and only a tiny
fraction suggests "X". One can beyond a reasonable doubt conclude that
"Y",given that the warrant for asserting "X" is small enough. One can
then be said to "know Y" even though "X" is true. This appears to be
more in line of how we actually come to "know" something than Ayer's
formulation.
Wittgenstein takes a stand against both Ayer and Chisolm.
Chisolm suggests that we start off with the notion of "knowing a
proposition". If though you know a proposition p then you also know
that a sentence s expresses that proposition p. My knowledge of
meaning ('x expresses x) is certain and does not depend on evidence.
It is therefore self-presenting. Chisolm does not consider knowledge
mediated by a sentence that expresses that knowledge.
Another oversight in Chisolm's work is the failure to discuss
what "having the concept p" really means. Wittgenstein states that
when one speaks of knowing what an "a" is one takes evidence from
one's behavior towards "a". Chisolm feels that when I speak of
"knowing what a is" arises because certain information is
self-presenting for the person who possesses it. Take the case of the
triple integral. Surely I know what a triple intyegral is but, not
being a mathematrician can I say that the knowledge of a triple
integral is self-presenting to me?
Wittgenstein advances the thesis that with sentences or
statements are associated warrants for the sentence's assertion or
denial. The statement for example, "I am certain that p"
psychologically implies p as contrasted with either Ayer or Chisolm
that take "p" as a seperate statement. Wittgenstein also makes the
point that the differences in two sentences make no difference if it
is seen that both have the same warrant for assertion.
How does Wittgenstein answer the sceptic? The sceptic would
say, "It is doubtful that I have two hands". Wittgenstein's response
would be simply, "What is the warrant for 'It is doubtful whether I
have two hands' ? There is none, hense the sceptical hypothesis is
nonsense". It appears what gets the sceptic into "trouble" is the fact
that doubting the existance of "x" makes sense for only SOME x not for
all x.
The final disagreement comes between Ayer and Wittgenstein.
Ayer in addition to stating tyhat philosophy is neither science nor
lexicography advances the propositions that each statement has a
logical form and that this "logic" is an extended form of formal
logic. There is a problem with this though. Consioger the following
statements:
1. It is doubtful whether I have a bright future.
2. It is doubtful whether I have a mother
3. It is doubtful whether I have a hand.
All these statements have the identical logical form yet, they are not
all valid (in fact only #1 is). Wittgenstein shows through these types
of examples that sameness in form can indeed mask differences in
warrants.
The concept of warrants for the assertions of statements also
allows us manage differing viewpoints of identical concepts in
different societies. You see the warrants for assertions for a
particular statement arise out of the linguistic environment. Certain
propositions for example, only make sense given that entire grups of
things are accepted as true. This allows us the freedom to know
certain facts conditionally. That is, we can know something just in
case something else is true. Scientific research and language learning
are examples of where the importance of previously "known" information
is crucial. These theories of epistemology are therefore more than
mental or rhetorical exercises. They help us adress some of the
questions how and why we thik in the manner that we do.