Philosophy
of Logic
Take
these well-known statements from the philosophy of logic. Namely:
(A)
The sentence A is not true.
And:
What I'm now saying
is false.
The
logical
argument
here is that we can grammatically assert the sentences above and
grammatically apply the predicate “is false” (or “is not true”)
to them. However, doesn't that depends on what's meant by the words “we
can grammatically assert the sentence”?
Now the sentence
This
sentence A.
or
even:
This
sentence.
is
surely not "grammatically acceptable". After all, the words “is not
true” are predicated of the words “The sentence A” (or “The
sentence”). Thus, what we're really dealing with are the words “The
sentence A” (or even the two words “The sentence”).
This
is roughly equivalent to saying
I
walk down.
or
even
This
is.
and
leaving the locution
there.
Surely no teacher of English grammar would accept this sentence on
its own.
In
other words, what if the logic and the paradoxes don't work if the
sentence has no semantic or propositional content? Or, to put that
another way, perhaps the paradoxes only arise because the sentence
“(A) The sentence A is not true” has no propositional content.
(Indeed wouldn't this also apply to the Liar Paradox?)
So
perhaps this well-known example from logic is all down to its syntax
and not its semantics. And if it's all down to syntax, then one can
see why some logicians have seen the sentence as being logically
acceptable. That is, it's about the form/syntax of these sentences
(as well as the problems/puzzles/paradoxes they create): not their
content. Though if that's true, isn't it a sleight of hand to use
sentences which appear to have content?
Indeed
a “non-cognitivist” position may state the following:
The Liar Paradox
isn't about propositional content.
Okay, perhaps
the Liar Paradox isn't about propositional content. Though what about
the sentence “(A) The sentence A is not true”; which doesn't take
exactly the same form as the
Liar
Paradox?
And why isn't the Liar Paradox itself also about propositional or
semantic content? Or, at the very least, why isn't content seen as
being relevant at all?
So
let's take another example. Say someone states the following:
I'm
lying to you at this very moment in time.
Then
a logician can go on to say:
No
one will say that the sentence “I'm lying to you at this very
moment in time” has no content.
Grammatically
speaking, the sentence “I'm lying to you at this very moment in
time” is a great sentence - grammatically. We all know what the
individual words means and it seems to make sense. However, what is
its propositional or semantic content?
The
statement “I'm lying to you at this very moment in time” could
have propositional or semantic content if the self-accusation of
lying refers to other
statements the speaker (or liar) had made previously. (Those other
sentences would then be false.) However, it's supposed to be a
self-referential statement. So what is this man lying about, exactly?
He can't be referring to his lying alone because in order to lie, you
have to make a claim that's false and also to believe that it's
false. Surely the fact is that he's neither lying nor telling the
truth.
Mr
X is only stating a grammatically-acceptable sentence; though one
which has no propositional or semantic content. Therefore he can't be
lying or telling the truth.
We
can now ask this question:
If
the sentence “I'm lying to you at this very moment in time” has
no content, then why is it still seen as still being grammatically
acceptable?
Now
compare
I'm
lying to you at this very moment in time.
with
I'm
singing to you at this very moment in time.
These two sentences aren't equivalent. And that's not simply because one is about
lying and the other is about singing.
When
someone says “I'm singing to you at this very moment in time”
he's either lying or telling the truth. (He could be singing those
words.) That doesn't work for the sentence “I'm lying to you at
this very moment in time”. The sentences have the same grammatical
form; though the latter is neither true nor false. The former is
either true or false. And even if they have the same grammatical
form, one is has a truth-value and the other doesn't. Indeed, despite what was said a moment ago, it can now be argued that it's because of this difference, the two sentences can't have
the same grammatical form.
Again,
because the sentences “I'm singing to you at this very moment in
time” and “I'm lying to you at this very moment in time” have
the same shape (or form), that creates problems. They may well have
the same grammatical shape. Though one could be true or false and the other is
neither true nor false. That difference seems to be clear.
Metaphysics
So
what about this more philosophical question? Namely:
Why
is water H2O?
Or:
Why
is the
speed
of light 186,000 miles per second?
As
well as:
Why
is the invariant mass of an electron approximately 9.109×10−31
kilograms?
We
can also add the following question:
Why
is water wet?
An
answer to the last question would presumably tell us about the
interaction of H2O
molecules and human skin; as well as facts about brains, central
nervous systems, sensory receptors, etc. It would also involve a
subjective component as to what
it is like
to experience something wet.
Liquidity
(not wetness),
on the other hand, can be explained by science and without recourse
to “phenomenal feels” (or experience generally).
Thus
perhaps we should ask the following question:
Why
do H2O
molecules give rise to liquidity?
That
question doesn't involve an experiential component.
However,
let's get back to this question:
Why
is water H2O?
Isn't
this question necessarily unanswerable or even meaningless?
Perhaps,
it's just a brute fact that H2O
molecules giving rise to water because they equal
water. In other words, this “brute fact” isn't amenable to an
explanation.
We
can also ask:
Why
is water constituted by H2O
molecules?
Or:
Why
do H2O
molecules bring about (or cause) water?
The
question
Why
does the brain/the physical bring about/cause consciousness?
is
similar; though certainly not exactly the same. For one, if we have
enough H2O
molecules, then we have water and can observe water. We can touch,
taste and see water when enough H2O
molecules are brought together (or found together). We can also see
H2O
molecules
under and microscope.
When
we observe brains, on the other hand, we can't touch, taste, or see
consciousness. We can experience or our own consciousness; though
only from the inside (as it were). So the
H2O-water
and brain-consciousness
questions are similar; though certainly not the same. Nonetheless, it
can still be said that the question is bogus
even if consciousness has what John Searle calls a “subjective ontology”; whereas
water-H2O
clearly
doesn't.
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