Tuesday, 13 February 2018
Bogus Philosophical Questions: Logic and Metaphysics (3)
Philosophy of Logic
Take this well-known statement from the philosophy of logic. Namely:
(A) The sentence A is not true.
What I'm now saying is false.
The logical argument here is that we can grammatically assert the sentence above and grammatically apply the predicate “is false” (or “is not true”) to it. Though doesn't that depends on what's meant by the words “we can grammatically assert the sentence”?
This sentence A.
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 are really dealing with is the words “The sentence A” (or even the two words “The sentence”).
This is roughly equivalent to saying
I walk down.
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.
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 as such, then why is it seen as still being grammatically acceptable?
I'm lying to you at this very moment in time.
I'm singing to you at this very moment in time.
The two 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 it can be argued that it's because of this difference that they 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 and the other is neither true nor false. That difference seems to be clear.
So what about this more philosophical question? Namely:
Why is water H2O?
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 have 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?
Why do H2O molecules bring about (or cause) water?
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.