What's Obvious about the Obvious

Absolute Truth Claims are generally greeted with skepticism and rightly so.  People are often crazy, megalomaniacal, deluded, overconfident liars with a profit motive.

Nevertheless, we are interested in truth - at least for ourselves in our own case.

Why are we interested in truth?

First there is the pragmatic reason.  In order to act rationally, that is, to act with knowledge guiding our actions, we have to believe that the knowledge we are putting in to practice is true or at least a good approximation to it.  If we act without knowing that our thoughts on a matter are true, then we are acting somewhat carelessly.  The degree to which we don't know whether or not our actions are appropriate is the degree to which we are acting out of ignorance.  Most people act out of ignorance most of the time.  And this isn't a problem because our guesses are usually really good - informed as it were in the background by the rest of what we know.  Meanwhile, though, many decisions we make are very well informed.  We rely on our base-informedness to help us make good guesses and move forward practically.

Secondly is the moral reason - being interested in the truth is honest, good, upright.

Thirdly is the intellectual reason - curiosity.

There have been many assaults on the notion of the truth through time - Buddhism taken in its most austere forms denies the notion of human knowledge and truth.  Medieval and Modern Skepticism, Physicalist Psychologism, and post-modern Deconstruction all count as fundamental attacks on rationality and truth - each of them denies the accessibility of truth to humans in various ways.  All of them also have a fundamental flaw which is the topic of our current discussion.

I like to say it's obviously true that there's truth and that we can know at least some of it.  But obviousness I know is a culturally relative and psychologically dependent term, so I'd like to try to give it a technical meaning that's adequate for our purpose here.

For my purposes, something is obviously true if and only if it couldn't possibly be false.

Now that's clear enough I think except for the term "possibly".  For again a question arises - possibly according to who?  One says that pigs could fly, another says they can't - who's right, how do we decide.  That's really our question and so we haven't moved forward very far yet.

And here I want to point out that even the term "possibly" can be given a strong meaning based on the law of non-contradiction - something can't possibly be true if it implies a contradiction.  And yet here we are again - what implies a contradiction? 

I think there are three main cases of this kind.  There are "surface contradictions" where the contradiction is apparent in the very sentence in which it's uttered.    Things like "The chair is in the room and is wholly outside of the room."  go in this category.  These I also term the "obviously false."  

A second category are "roundabout contradictions" - these are congregations of sentences which taken together imply a contradiction.  For instance:

My mother is in the bathroom.

The bathroom is on mars.

My mother is not on mars.

--- no single sentence is obviously a contradiction but taken together we know one must be false.

The last category I'd like to think about are "self-defeating contradictions" - that is contradictions that, though they seem possible, nevertheless imply a contradiction.  These are the trickier ones.  Here I don't merely mean complicated "roundabout contradictions" but rather contradictions which if true imply their own falseness in some other way.

Thus for instance, the sentence "I don't exist" while not a contradiction in either of the straightforward senses above, must be false if uttered intentionally, e.g. in order to be thought of as true.  

This sentence is self-defeating because if it were true, the person who uttered it would not have been there to utter it.  But since we know that if uttered, someone uttered it, we know it to be false whenever uttered.  There are other ways that other sentences can be self-defeating.  I don't think there is a limit to the number of ways that sentences can be self-defeating in this way.  I do think that self-defeat-ability is finally reducible to complex cases of roundabout contradictions, but that they are nevertheless a special case of them - the cases where the speaking of something itself implies its own falsity.  The specialness is due to the fact that such sentences have existential import.  That is - the very existence of the sentence, utterance or proposition in question is what provides the hidden contradiction.

This existential import is obviously different from the other kinds of contradictions.

We know without knowing what beevils are that if all beevils are numbly and grohan is a beevil then beevil is numbly on pain of contradiction.  What we don't know from such games is whether or not there are any beevils at all and so whatever we may prove from this a priori formal "game" theorem, we can never actually prove anything about beevils.  

In the case of the self-defeating contradiction, we can prove something positive as a result of their obvious falsity.

In the famous case of DesCartes' Cogito we have such an argument.   The "I" that utters "I think" must be there to utter it, otherwise, it must obviously be false - in that the assumption that it was false would imply a self-defeating contradiction.

Thus "I exist" when uttered must be true.  Whatever "I" is, if it utters it, it's so.

And now we have the tools we need to get where we wanted to go.

It follows that if there are such absolute truths, that each of skepticism, post-modernism and psychologism are simply false.    That's a truth you can act on, count on, live by and be convinced of without reference to any sales pitch.

Skepticism is the theory that there are no truths or less worryingly, that no truths can be known.

But we know that there must be truths, for if there were no truths, then the following sentence would be true, but it is a self-defeating contradiction:

"There are no true sentences"

If it were true, then it couldn't exist.  But there it is.  Consequently, it must be false.

And we obviously know it.  

With deconstruction we have a slightly more virile anti-transcendentalism - a deconstructionist might say that the context in which the utterance in question is hypothetical and not determinable, and so the meaning of it is hopelessly vague.   But this is a mistake.  While we do depend on interpersonal communication's possibility, we also have a handy argument for its necessity. (roughly from wittgenstein).

If there were no interpersonal communication, then these words I'm using would be meaningless for their meaning is dependent on people using them for communicating.

This argument taken rightly, is again of the transcendental form:

There are no meaningful or understandable sentences.  

Is obviously false, for if true, it's meaningless.  How can a meaningless sentence be true?

And now we have in our hands our double-edged sword - truth and meaningfulness.

With it we can defeat many foes.  Which we will defeat is going to have to wait until tomorrow.