I’d like to run an idea past all of you and get your
reactions. My apologies for the length
of this – I don’t know how to say this more briefly.
I’m going to use the word “random” here primarily in sense
of being a property of a sequence of events that makes the n+1st event
unpredictable from the first n events.
This probably conflates the words “chance” and “random” as they are used
in the SEP article, but I need to get a bit more comfortable with that distinction
before I start using it.
A distinction is often made between epistemic and
ontologically random processes. The
former means the events it generates are unpredictable but with enough
additional knowledge, it could be made predictable. The latter typically means that no amount of
additional knowledge could render the events predictable. Some statisticians and scientists have
regarded this distinction as of no practical importance since none of their practices
with actual data would be any different for an epistemically random or an ontologically
random process. However, philosophers
and some philosophically oriented scientists still regard the distinction as
important on ontological grounds. That
is, if all randomness is epistemic, then the world is deterministic. If ontological randomness exists, it is
not. So, they argue, much of how we see
the fundamental nature of reality hinges on this question.
I’d like to argue that the distinction is not
philosophically meaningful either.
Consider the example of gender selection for a child. (The argument applies to any genetic factor
in any organism that reproduces sexually, but, for clarity’s sake, let’s keep
it simple.) It’s certainly random. Is it epistemic or ontological? Well, the process is incredibly complex. Enormous numbers of sperm are swimming around
prior to ejaculation and the timing of which one is best positioned to win the
race is critical. And who can predict
which one is the best swimmer? Also,
there are roughly 100 million conceptions each year and (with the exception of multiple
births) these are independent of one another.
However, one could argue that with enough detailed knowledge, the uncertainty
as to which sperm wins could be eliminated; furthermore, complete knowledge of
timing could render the independence irrelevant. So a case could be made for this being
epistemically random. However, that
level of detailed knowledge is, for many reasons, inaccessible to human
beings. But perhaps it is accessible to
God, so from the divine perspective, gender selection is epistemic. But let’s suppose for the moment that God
does not normally direct the gender selection process; in Thomistic terms, he
uses it as a secondary agent, in this case, a non-deterministic one. So this means that even though the detailed
knowledge that would enable prediction might be available to God, He does not
use it. Let’s go even further and
suppose God created it to be a non-deterministic process. Then it follows that non-determinacy is a fundamental
property of that process. If that’s the
case, it would seem inappropriate to deny its ontological randomness. That is, if one defines ontological
randomness as “not epistemic,” gender selection is not ontologically
random. But if one defines it in terms
of the properties of the process God gave it, it is ontologically random. Thus, in this sense, it is both epistemically
and ontologically random. So the distinction
between them breaks down.
Of course, I still haven’t addressed the question of why I
think God created the process to operate non-deterministically. I
appeal to two principles: (1) inference to the best explanation, and (2) divine
goodness. The process of gender
selection along with diffusion, quantum collapse, mutation, the operation of
the immune system, and many others appear random. There is no observable evidence of a hidden
agent directing them but a straightforward, transparent explanation can be
given in terms of non-determinacy. So it’s the better explanation. Also
as Einstein put it, “The Creator is subtle but not malicious.” So I would call all of these processes
ontologically random without denying the possibility that knowledge may be
obtainable that reduces their uncertainty.
This question was precisely what Bohr and Einstein argued for twenty years and Einstein lost. There is ontological randomness in the world. I think this has to be considered one of the most metaphysically significant advances in all of science, eclipsed only perhaps by the discovery that there are natural laws.
ReplyDeleteI do think though, that those of us who have studied physics, or spent time learning quantum mechanics, need to appreciate how utterly counter-intuitive it is for many scholars to insist on ontological uncertainty over mere epistemological uncertainty. One reason why Randomness is so feared is that, if real, it suggests that some mysterious unknowable "cause" is present.
Robert Wright told me that, in a debate with Dan Dennet (sorry I have no link) he forced Dan to admit that "no cause within this physical universe accounts for quantum events." He was making the point, of course, that God could certainly influence quantum events from "outside" the universe and it would look exactly like what we encounter.
Would Einstein have won if Bohm's theory had been proposed in 1925? I.e., if a deterministic version of QM had been a live option from the start, would we still be talking about QM and ontological randomness?
DeleteExcellent point, Jeff. Both Einstein's view and that of Bohm are philosophical interpretations of the underlying mathematical laws of (non-relativistic) quantum mechanics. Jim Cushing has an excellent book on the 'hegemony' of Bohr's Copenhagen view (with Heisenberg's addition of ontological indeterminism) versus Einstein / Bohm on determinism (although non-classical, non-local). So until we can decide which interpretation is "correct" all we can do is assume one of them, state clearly that we are doing so, and follow out the consequences for theology. That's what I do with QM-NIODA>
DeleteJim, I'm not following why the distinction breaks down. Epistemic and ontological randomness are not mutually exclusive. One can't define the latter as not being the former. If a process is ontological random then it will be epistemically random.
ReplyDeleteI would prefer to say that ontological randomness presupposes epistemic randomness but epistemic randomness is neutral to whether or not there is ontological randomness. Polk claims that "epistemology models ontology" but it certainly isn't a proof that where there is epistemic randomness there must be ontological indeterminism.
DeleteThis conversation has helped clarify my thinking. What Jeff and Bob say here about epistemic and ontological randomness seems right to me.
DeleteWhat I'm trying to get my mind around is a different way of thinking about randomness than is done in quantum mechanics. That is, QM leads us to think about the possibility of inherent randomness of quantum processes versus the alternative possibility of hidden global variables. However, I think that a lot of randomness that occurs in the natural world is quite different from this - it's what I'm tentatively calling "anarchical randomness." For example, consider a device detecting electromagnetic radiation from outside the earth’s atmosphere. The arrivals will follow a Poisson distribution. But each individual photon that arrives behaves according to deterministic laws. The randomness is the result of the interaction of a huge number of independent events. Even though the individual events can be considered deterministic the system as a whole appears to be a random process. Note the similarity and differences from deterministic chaos. In the latter the unpredictability arises from (1) our inability to precisely state the initial conditions and (2) the amplifying effect of the system’s dynamics. In the radiation example, the unpredictability arises from (1) our inability to know the whereabouts of all the photons that might arrive at the detector and (2) their independence. And if there is no one orchestrating the whole process (that is, if God does not directly manage the individual photons but allows them to function according to their own natural laws), the randomness is no longer merely apparent but is a fundamental property of the system. So it seems to me that the randomness is ontological but in quite a different way than in the Copenhagen interpretation of QM. Put differently, any complex system with a large number of independent components will exhibit randomness.
But the existence of such randomness is important to understanding at least some aspects of divine action, it seems to me. That is, if one assumes universal divine causal determinism, there is a hidden manager. But if one doesn't assume that, it means that God has created, sustains, and uses indeterminate processes. Mathematical results such as the Central Limit Theorem suggest to me that God has built both randomness and ways to manage it into creation from the beginning. There's a lot more that can be said but I'll stop here for now.
Does this make sense?
Hi, Jim, it's Bob. One thing to note is a possible conflation between classical and quantum ways of looking at your example of "anarchical randomness." From a classical perspective the electromagnetic waves obey the deterministic EM wave equation and produce a Poisson distribution of at the detector. But when you refer to individual photons and their independence we've switched to a quantum mechanical perspective where photons obey the deterministic Schroedinger equation but produce a Bose-Einstein distribution on the detector reflecting quantum indeterminism (and the distribution becomes Poisson in the correct limits). So the quantum indeterminism is there, it just doesn't show up in the classical limit / Poisson distribution.
ReplyDelete