I’m curious to see how devoted Objectivists respond to this essay (or if they know of any systematic responses elsewhere).
http://members.aol.com/kiekeben/rand.html
The gist: Rand defines causation in terms of entities themselves acting on each other (not through some intermediary idea of action or force), and insists that cause and effect is an instantiation of the “nature” of entities acting on each other. But this would seem to commit Rand to some sort of determinism–since if bodies only act through their “natures,” then it follows that there is no effect without a wholly natural cause. This seems to rule out any effect that isn’t a necessary result of its cause. It is not clear how human volition turns out to be anything more. (Unless–as I recently pointed out to Kiekeben in private correspondence–we are willing to commit ourselves to different laws governing mental action than govern everyday causation. But this devotes us to some form of dualism, and is obviously non-Randian.)
Determinism can be refuted without reference to free will. The determinist principle that each action entails a single possible consequent action is an arbitrary assertion that cannot be proven. Considered as a simple restatement of the causality principle determinism fails because it unjustifiably restricts what is possible. Unjustifiable, because philosophy can not be normative by specifying apriori what physics must discover. Philosophy can only specify what kind of thing is impossible, a contradiction.
Determinism also invokes an infinite regress of causes unless there actually was a metaphysical first cause. But if determinism can have one first cause then it can have others and ‘single possible consequent action’ is a false premise.
Kiekeben understands and agrees that determinism does not follow from causality. His chief complaint lies in this concluding passage:
… That every entity always acts in accordance with its nature tells us nothing about how it will in fact act, including whether or not there is more than one possible way for it to act. It does not, for instance, rule out the standard interpretation of quantum mechanics: all one needs to say is that it is in an electron’s nature (for example) to behave unpredictably. Nor would it be contradicted by a helium-filled balloon that fell. If a balloon ever acted this way, then that would merely show that such behavior is part of its nature. Or, in other words, no matter how anything acts, it is by definition acting in accordance with its nature.
The point being that knowledge is impossible in a magical universe where any entity might do anything at any time, because any entity is always trivially “acting in accordance with its nature.” This is the problem behind validating the methods of induction, and is the root of skepticism. Ayn Rand did not solve this problem so there is no official Objectivist response, but Leonard Peikoff claims to have done so in his lecture course Induction in Physics and Philosophy.
My order has not yet arrived, so I don’t know the proper response.