View Single Post
bohm2 is offline
Nov12-11, 06:01 PM
PF Gold
bohm2's Avatar
P: 670
Is causality the same thing as determinism? What's the difference in meaning between determinism and causality? Is causal indeterminism possible? I'm asking because there is some debate in this area whether, in fact, the 2 terms are the same or even if they're in conflict. Just to hi-lite some of these difficulties, consider Carl Hoefer's entry in Stanford Encyclopedia of Philosophy on "causal determinism" where he opts from refraining discussing the "causal" part:

In most of what follows, I will speak simply of determinism, rather than of causal determinism. This follows recent philosophical practice of sharply distinguishing views and theories of what causation is from any conclusions about the success or failure of determinism (Earman, 1986; an exception is Mellor 1994). For the most part this disengagement of the two concepts is appropriate. But as we will see later, the notion of cause/effect is not so easily disengaged from much of what matters to us about determinism.

Even more forcefully consider his paper here:

Causality and Determinism: Tension, or Outright Conflict?

Furthermore with respect to QM and determinism he writes (In Stanford entry):

As indicated above, QM is widely thought to be a strongly non-deterministic theory. Popular belief (even among most physicists) holds that phenomena such as radioactive decay, photon emission and absorption, and many others are such that only a probabilistic description of them can be given. The theory does not say what happens in a given case, but only says what the probabilities of various results are. So, for example, according to QM the fullest description possible of a radium atom (or a chunk of radium, for that matter), does not suffice to determine when a given atom will decay, nor how many atoms in the chunk will have decayed at any given time. The theory gives only the probabilities for a decay (or a number of decays) to happen within a given span of time. Einstein and others perhaps thought that this was a defect of the theory that should eventually be removed, by a supplemental hidden variable theory[6] that restores determinism; but subsequent work showed that no such hidden variables account could exist. At the microscopic level the world is ultimately mysterious and chancy.

So goes the story; but like much popular wisdom, it is partly mistaken and/or misleading. Ironically, quantum mechanics is one of the best prospects for a genuinely deterministic theory in modern times! Even more than in the case of GTR and the hole argument, everything hinges on what interpretational and philosophical decisions one adopts.