“This blog is false.” ~
Theory Parker
In my free time, which is
almost never these days, I like to think about paradoxes and the flaws that
lead to their apparent existence. Paradoxes – statements that seems
contradictory but may be or seem true – come in several types; they may be
paradoxes of logic, of self-reference, of statistics, of probability, of
vagueness, of mathematics, of geometry and even of physics. For the sake of
brevity, I am going to focus on three paradoxes today that relate more to
philosophy and demonstrate why they are in fact not paradoxes. I will start with one of the most famous of all, one
of Zeno of Ela’s paradoxes, Achilles and the tortoise.
Achilles
and the Tortoise
Solutions and rebuttals to
this paradox have been offered by Aristotle, Archimedes, Thomas Aquinas,
Bertrand Russell and philosopher Nick Huggett, with only the physicist Peter
Lynds and mathematician Hermann Weyl coming close but still missing the mark.
I’ve always found this puzzling as the solution to this paradox – thus not
making it a paradox – is incredibly simple: The paradox is only a true paradox if
we’re talking about Achilles and the tortoise as two-dimensional beings on a
two-dimensional plane. But this is not the case in reality. In reality we live
in three dimensions of space and one of time, to say nothing of the fact that
the Earth is rotating while hurdling through space during which our solar
system orbits the galactic center which is itself winding its way away from
other galaxies as space is expanding. So, when Aristotle says something like, “In
a race, the quickest runner can never overtake the slowest, since the pursuer
must first reach the point whence the pursued started,” it cannot be true that the faster runner
ever occupies the same point in space (much less time) that the slower runner
has started from, no matter the given starting point for the slower runner.
Another way to put it would be to say that if we point to the starting point of
the slower runner and tell the faster runner to go there, the faster runner may
go to the same geographical location but the geographical location has changes
its position in space-time by the time the faster runner gets there. And if the
faster runner is fortunate to have the Earth rotate towards them as they run,
they are in fact that much quicker (though this increase in speed is not
detectable by human senses).
Zeno’s
paradox here, like his other paradoxes of motion, winds up failing on account
that he perhaps didn’t know about the four dimensions we live in. Furthermore,
Zeno appears to make the mistake that time is static; that there is no flow to
time. While time may occur in discreet packets at the quantum level (i.e. Plank
time), there appears to be no interruption in the flow of time at the
macro-level of the physical world. If Zeno has bothered to listen to his
contemporary Heraclitus who said, “Everything is in flux,” Zeno would have
readily seen the flaw in his paradox and never come up with his tale of
Achilles and the tortoise.
“This
Sentence is False.”
“This sentence is false,”
is probably the most well-known version of the Liar Paradox and is categorized
as a self-referential paradox. Quite simply, the apparent paradox is this: If
"This sentence is false," is true then the sentence is false, but if
"This sentence is false," is false, then the sentence is true.
I deny this is a paradox
on two accounts. The first is that despite appearances, the sentence actually
has no subject with which to refer to. The subject in question, “This
sentence…” if taken by itself as a phrase, can have no truth value in the same
way a phrase like ‘this book’
does, seeing how ‘this sentence’ is an abstract
concept and ‘this book’ refers to an object in reality. That is to say,
abstractions cannot have truth values, or perhaps it is more precise to say
they have no truth values in reality, outside of individual minds. While a
unicorn may exist as an abstract within our minds, unicorns don’t actually
exist in reality. As such, I am of the position that abstractions have no truth
or false values. If something has no truth value universally to all people
everywhere, it simply has no truth value at all; the word, phrase, or sentence
in question is ultimately devoid of truth or falsity.
Furthermore, I object that
abstractions can reference themselves and maintain any truth value simply
because referring to itself as being true or false cannot be verified. If a
unicorn says, “This unicorn is true,” we don’t know what about the unicorn the
unicorn is saying is true much less know whether or not the unicorn is lying,
especially when unicorns don’t even exist in reality.
“This sentence is false,”
is merely a nonsensical utterance derived from the contrivances of language.
Ship
of Theseus Paradox
A little more challenging
is this paradox brought to us by the Greek historian, Plutarch. He writes in
his Theseus, "The ship wherein Theseus
and the youth of Athens returned from
Crete had thirty oars … they took away the
old planks as they decayed, putting in new and stronger timber in their places,
in so much that this ship became a standing example among the philosophers, for
the logical question of things that grow; one side holding that the ship
remained the same, and the other contending that it was not the same."
What Plutarch is asking is if parts are taken away from the ship and replaced
which new parts though of the same design, is it still the same ship?
Furthermore, would it still be the same ship if all the pieces were eventually replaced? Further furthermore, if
all the parts were eventually replaced with new ones and the old pieces were
reassembled just as they had been on the ‘old’ ship, which ship is actually
Theseus’ ship?!
Aristotle thought he’d
solved this paradox by invoking four criteria (he called them ‘causes’) for the
‘identity’ of the ship. They include the Formal Cause (the ship’s design), the
Efficient Cause (how the ship was built), the Material Cause (what the ship is
made of), and the Final Cause (the purpose for which the ship is made). Aristotle
was mostly concerned with a thing’s formal cause, so as far as he considered
the problem, there was no paradox because despite the replacement of parts – no
matter how extensive – resulted in the same design. This also satisfied
Aristotle’s second most import cause, the Final Cause, since the design still
allowed for sailing. So, if we were only concerned with the idea of Theseus’ ship, the ‘form’ of
Theseus’ ship, then both ships are Theseus’ ship (which puts aside the question
of ownership). But since Aristotle added criteria that to him indicated that
only the ship that was still worthy of sailing was Theseus’ ship. Of course, if
both ships are sailable, Aristotle’s argument sinks.
The solution that most
philosophers ignore because it is just too obvious, is to say that Theseus’
ship is whichever one he owns and is
at the helm of. If Theseus had paid for one single ship, there might be a
question as to which ship he actually owns, but by adding that Theseus must be
at the helm of the ship as well quite quickly resolves the apparent paradox. While
the pieces of the ‘old’ ship may have been taken away and reassembled, it is
not Theseus’ ship. It was Theseus’
ship but not anymore, just like there was a paradox but not anymore.
Have
a paradox you need solved? Just send them to pi3.onefour@gmail.com and I’ll get back
to just as soon as I return from time-travelling to the past to kill my grandfather.
No comments:
Post a Comment