It's
tempting to think that the nature of quantum mechanics is the primary
reason why Graham Priest defends and accepts dialetheic logic (or dialetheism generally).1 Indeed, he mentions quantum mechanics (QM) in various
places.
We can now ask if quantum nature affects macro-reality (or, at the least, the "Kantian world" as it's perceived and/or experienced). Perhaps, if dialetheic logic (DL) is truly dependent on the findings of quantum mechanics, we can also ask if dialetheism is applicable to the “classical world” at all. Of course I may be barking up the wrong tree here. That is, why assume the relevance of this macro-/micro-world opposition to dialetheic logic?2
We can now ask if quantum nature affects macro-reality (or, at the least, the "Kantian world" as it's perceived and/or experienced). Perhaps, if dialetheic logic (DL) is truly dependent on the findings of quantum mechanics, we can also ask if dialetheism is applicable to the “classical world” at all. Of course I may be barking up the wrong tree here. That is, why assume the relevance of this macro-/micro-world opposition to dialetheic logic?2
In
any case, what has Priest got to say about what he calls
“[u]nobservable realms”? (A term which need not only refer to the
quantum world; but also to historical events, events beyond our
galaxy, numbers/abstract objects, etc.) Take this passage:
“...
it would sometimes (in the well-known two-slit experiment) appear to
be the case that particles behave in contradictory fashion, going
through two distinct slits simultaneously.”
Dialetheic logic would be an ideal logic to describe or capture such a
phenomenon. Nonetheless, Priest's clause “it would sometimes...
appear” does seem to qualify things a little. In other words, since
Einstein, hasn't the
supposed “contradictory” (or paradoxical) nature of quantum
phenomena - or states - been questioned by various physicists
(including David Bohm)?
Nonetheless, that may not be
relevant anyway.
More
broadly, Priest says that “inconsistent theories may have physical
importance too”. At first
blush, we can ask:
And, if so, what's the connection in particular instances? What Priest continues to say may mean that not only is this statement unconnected to dialetheism; it may not be connected to QM either. He continues:
Does inconsistency necessarily have a connection with dialetheism?
And, if so, what's the connection in particular instances? What Priest continues to say may mean that not only is this statement unconnected to dialetheism; it may not be connected to QM either. He continues:
“An
inconsistent theory, if the inconsistencies are quarantined, may yet
have accurate empirical consequences in some domain. That is, its
predictions in some observable realm may be highly accurate.”
Since
Priest is talking about an “observable realm”, this mustn't be
about QM. (Then again, some of the clues as to the reality of QM are indeed
observable.) Not only that: talk of the “accurate empirical
consequences” of theories is something that's widely accepted
throughout the sciences. Indeed Priest finishes off by saying that
“one may take the theory, though false, to be a significant
approximation to the truth”.3
Priest's Examples From QM
Here's
a passage from Priest on an aspect of QM that's relevant – or not! –
to dialetheism:
“Unobservable
realms, particularly the micro-realm, behave in a very strange way,
events at one place instantaneously affecting events at others in
remote locations.”
It's
difficult to see how this physical phenomenon has any direct
relevance to dialetheism. Nothing contradictory/paradoxical is
happening here; unlike the two-slit experiment. What's does happen,
however, does indeed go against common-sense views of causation.
Nonetheless, that doesn't automatically seem to entail contradiction or
paradox.
Priest
gives another example of quantum happenings. This example is one of
radioactive decay. He writes:
“...
suppose that a radioactive atom instantaneously and spontaneously
decays. At the instant of decay, is the atom integral or is it not?”
Now
for the traditional logic of this situation. Priest continues:
“In
both of these cases, and others like them, the law of excluded middle
tells us that it is one or the other.”
Couldn't
the atom be neither integral nor non-integral when it
instantaneously and spontaneously decays? (Priest talks of either/or
or “one or the other”; not neither/nor.) Or, alternatively, at
that point it may not be an atom at all!
This
appears to be a temporal problem which must surely incorporate
definitions - or philosophical accounts - of the concepts
[instantaneously] and [spontaneously].4
Nonetheless, if they define time instants that don't exist (the
period from t to t1 doesn't exist), then
Priest and others may have a point. However, can an atom - or
anything else - “decay” (or do anything) in a “timespan”
which doesn't actually exist? How can decay - or anything else -
occur if there's no time in which it can occur?...
So
what of Priest's own logical conclusion when it comes to
atomic decay? He claims that the aforementioned atom “at the point
of decay is both integral and non-integral”. This isn't
allowed – Priest says - if the law of excluded middle has its way.
The law of excluded middle tells us that the said atom must either be
integral or non-integral; not “both integral and non-integral”.
I
mentioned abstract objects in brackets earlier: Priest himself
“move[s] away from the empirical realms” to “the realm of
sets”. This realm “appears to be inconsistent” too. Here
again Priest uses the word “appears”. There are indeed paradoxes
in set theory; though haven't logicians and mathematicians - like
physicists in QM - attempted to rectify those inconsistencies or
paradoxes? True, unsolved, these inconsistencies/paradoxes - again
like QM - are perfect specimens to be dealt with - and captured by -
DL. Nonetheless, it can be said that what's captured isn't a world or
reality of any kind: it's simply an unsolved paradox or
inconsistency. In addition, just as we asked about how DL could be
applied to the empirical world, so we can also ask what the
connection is between the paradoxes of set theory and the empirical
world. Despite that, it seems clear that set theory needn't have a
necessary connection to such a world; though that will depend on a
whole host of factors. (Such as what one's take is on the reality or
existence of the members of sets, etc.)
If
one believes in abstract objects such as sets, then they must exist
in an abstract world. Thus DL, in this case, may be applicable to a
world – an abstract world. (These vaguely platonic announcements
about sets and abstract objects will, of course, be rejected by
certain philosophers, logicians and mathematicians.) 5
Again,
none of this philosophy of science - on Priest's part - is solely
applicable to QM or dialetheism. I say “solely” because Priest
does indeed give an example from QM. He says that “those who worked
on early quantum mechanical models of the atom regarded the Bohr
theory [as] certainly inconsistent”. And “yet its empirical
predictions were spectacularly successful”.
Needless
to say, it must be stressed here that the word “inconsistent” is
very different to the word “contradictory” (or “paradoxical”).
Something can indeed be inconsistent because contradictory. Though
can't something also be inconsistent without being (logically)
contradictory?
Conclusion
Again, if dialetheism logic is all about QM, then why
not call it a logic of – or a logic applicable to - quantum
mechanics? If dialetheic logic is (as it were) justified by the
nature of quantum reality, then it may also depend on it.
Nonetheless, there's a tradition in logic which states that logic, in
a strong sense, doesn't depend on anything – least of all on the nature of the/a world. (Wittgenstein, at one point, stated this
position; and the early Russell took the contrary view.) If that were
the case, then it may also be the case that dialetheic logic isn't
dependent on the nature of QM. It just so happens that QM sometimes –
or many times – behaves in a way which can be captured by
dialetheic logic. Nonetheless, this doesn't mean that DL is dependent
on QM. And it doesn't mean that DL is derived - in any way - from
QM either.
Despite
saying that, Priest does clarify his position by saying that the
True. Though, again, is dialetheism independent of QM? And, in parallel, is it applicable outside that “micro-world”? Perhaps Priest would reply:
Indeed need logic be applicable to the/a world at all?
“micro-realm is so different from the macro-realm that there is no reason to suppose that what holds of the second will hold of the first”.
True. Though, again, is dialetheism independent of QM? And, in parallel, is it applicable outside that “micro-world”? Perhaps Priest would reply:
What does it mean to ask if DL is applicable to the macro-world?
Indeed need logic be applicable to the/a world at all?
***************************************************
Notes
1
This case parallels - at least to some extent - ontic structural realism, which (it can be argued) is similarly motivated by the reality of QM. Or to put that another way: what relevance does much of the ontic
structural realist position have to the macro-world? (See here
for my discussion of this subject.)
2
Priest is also inspired by Buddhist logic (or simply by Buddhist thought).
So, conceivably, this piece may just as justifiably have been
entitled 'Is Graham Priest's Dialetheism a Logic of Buddhism?'
3
This chimes in with Popper's verisimilitude
in which scientific theories have quantifiable truth-to-falsity
contents.
4
Perhaps, as hinted at earlier, what's needed is some good
old-fashioned conceptual analysis of the words “integral”,
“non-integral”, “decay”, “spontaneously” and
“instantaneously”. Not, of course, the kind of conceptual
analysis which historically disappeared up its own backside (i.e., by
ignoring science completely). Nonetheless, if quantum reality is the
way many physicists say it is, then much conceptual analysis on this
matter will either be wrong or simply inapplicable to the quantum
domain.
5
What is - or what constitutes - a world anyway?
Reference
No comments:
Post a comment