Time, free will, and the first person perspective, Part II

From a global, third-person perspective, free will and the flow of time make no sense. That goes for any global perspective–scientific, religious, or philosophical. The best that can be said for free will is what Kant said: we must treat ourselves as free agents when we are making decisions. However theoretically incoherent, free will seems to be an unavoidable pose for practical reasoning. “I will do whatever I am causally determined to do” (or “I will make a nondeterministic random choice”) may be true, but doesn’t help when we are in the midst of making a decision.

Laplace asserted that a demon with complete knowledge of the universe at one instant in time could, using the laws of Newtonian mechanics, predict the entire future and infer the entire past.  Karl Popper later realized that this couldn’t possibly work if the demon is itself part of the universe.  Then the demon would have to be able to predict his own future choices.  But suppose he decides to do the opposite of whatever he predicts he will do? We have a paradox. Paradoxes related to self-reference like this were used by Russell to critique “naive” set theory and can be used to prove the undecidability of the Halting problem over Turing machines.

It has been argued by Thomas Breuer that no observer can perform a complete measurement of the state of a system of which it is a part.  For the proof, a self-measuring system consists of a total system with its list of possible states, the measuring apparatus with its list of possible states, and an inference map that associates sets of apparatus states with sets of total system states.  Breuer makes an assumption of “proper inclusion”, i.e. that the apparatus is a proper part rather than the whole, and interprets this to mean that there are distinct system states with the same apparatus state.  Given this, the conclusion is unsurprising.  Notice how the problem is set up.  One could, I suppose, identify the measuring apparatus and the system itself, and then say that the system perfectly “measures” or “knows” itself simply by being itself and in whatever state it’s in. Clearly this is not measurement or knowledge as normally understood, which requires a duality between subject and object and a representation of the latter in the former.

For the impossibility of complete self-knowledge, it doesn’t matter whether the knowing being is deterministic or not. Descartes realized correctly that consciousness involves privileged knowledge of itself. In the 20th century, we realized that a being’s perspective necessarily also involves a certain ignorance of itself.

I am a unique perspective of the whole universe, as Leibniz taught us. (To quote Wittgenstein “I am my world.”) This distinctive perspective is necessarily partial. In particular, some degree of knowledge of myself is only possible from an outside perspective. (Wittgenstein again: “The subject does not belong to the world but it is a limit of the world.”)

This, I believe, is what greater minds than mine have found troubling. If the flow of time and freedom of the will are necessarily connected to a limited perspective, can only be conceived from a combination of knowledge and ignorance, then doesn’t that mean that my first-person perspective is an illusion, is a lie? And that the only truth is the third-person perspective of science and religion?

To be continued