[Doctor Stochastic]

But even in principle, one cannot predict Brownian motion. Measuring instruments small enough to measure the motion are subject to Brownian motion themselves.

From the point of view of Aristotle's "efficient cause," Brownian motion (or QM) is "uncaused" because no causal "event" preceeds the measured event. However, from the POV of Aristotle's "material cause," both Brownian motion (and QM events) are causal. The events are "caused" by the preceeding state (rather than a preceeding event.) The "material cause" does not rule out a probabilistic cause.

For example, a kaon may becay into two neutral pions or a positive pion and a negative pion. The question: "Why did the neutral pions occur?" can be answered by showing the kaon. The question: "Why did the charged pions occur?" has the same answer. The question: "Why charged rather than neutral?" (or vice versa) cannot be answered (I'm not sure the QM formalism allows it to be asked.) The kaon decays one way or the other at random. There is no possible information about the kaon that can indicate which path is chosen. Material causes do not lead to efficient causes.

All proposed modifications, replacements, foldings, spindlings, mutalations, adaptations, etc. of QM have failed to give an efficient cause to tell which path a kaon may take. One problem with all such approaches is that they are required to reproduce experimental results in other cases.

[Right Wing Professor]

But even in principle, one cannot predict Brownian motion. Measuring instruments small enough to measure the motion are subject to Brownian motion themselves.

To some extent the scientists and the non-scientists are arguing somewhat at cross purposes. You seem to be arguing, as I am, that a system can be said to be deterministic if we can model it - that is, if we can set up a computation that predicts its behavior. By this standard, sure, Brownian motion is not deterministic; and if it will ever feasible to model a human brain, we're a long way from even being able to demonstrate the possibility.

Alamo-Girl is taking a Platonist view; that if the system works according to a set of physical laws, it is deterministic, because it's theoretically possible (even if utterly infeasible) to predict its behavior at any point in time. As I noted earlier, QM says that if the wavefunction of the universe is psi, then d psi/dt is just -i*hbar*H*psi, and it's just a very big Runge Kutta problem. :-)

Maybe we should make a distinction between empirical determinism and essentialist determinism.

[Alamo-Girl]

Thank you so much for your post and for the examples! I believe RWP is explaining my Platonist view rather well. Thank you!

All that I wish to add is that our (current) inability to predict the effect of a cause does not mean that the effect would have happened without the cause. Thus the sum cause/effect is preserved over a perceived timeline from a beginning. Moreover, even if the cause were a random effect generator it would nevertheless be a cause which would not exist except as the effect of the beginning cause.

My point of bringing this up is that it is characteristic of a strongly deterministic worldview.

To the contrary, my Christian worldview allows for non-spatial, non-temporal and non-corporeal existents - and in the area of physicality, extra spatial and time dimensions.

BTW, Doctor Stochastic, how did you achieve randomness via programming in the gaming example?