You have heard me discuss partial determinism a number of times. Now I wish to explain it in some more detail. In this letter I propose, in the main, to lay out what the theory is, rather than come up with arguments to recommend it other than its power and elegance. Of course the power and elegance of a theory are always its most persuasive features, rather than, pace you, any empirical evidence in its favour. Furthermore, in many cases a view does not stand in need of defence, but attack. For example, it is not an idea that needs defending than snow is white. If you wish to disagree with this, you do not merely need to attack any reasons I might put forward in its favour. Almost the whole burden of proof lies on your side, to display somehow that snow is not white. That is, that snow is white is not a view that needs defending, but a view that needs attacking, if one wishes to hold a different view. Now in the matter of partial determinism I do not suggest that as a whole the view is one that needs attacking, not defending, but rather that all its most controversial elements are of this nature. This may seem obscure at the moment, but I hope all will become clear shortly.
What is partial determinism? Briefly, partial determinism is the claim that at any particular time the truth values of some propositions in the future tense are defined, and those of other propositions are not. Propositions about the future would include: “The sun will rise within the next twenty-four hours”; “I shall never talk to you again”; “The Labour Party will win the next General Election”. If the truth value of a proposition is defined then either the proposition is true, or the proposition is false.
Now to be clear: I am making an ontological claim, not an epistemological one. I am not saying that there are some truth values that it is impossible for us to discover, and hence that they are ‘undefined to us’. That is, I am not saying that although all well-formed propositions about the future have defined values, there are some, indeed possibly all of them, that we can never discover. No. I am saying that some propositions about the future as yet have no truth value. Furthermore, because the theory is partial determinism, this is not because it is inherently impossible for a proposition about the future to have a truth value, since I am making the additional claim that some propositions about the future do have a defined truth value. Thus on the ontological question there are three possible positions (among those who believe in bi-valued truth functions for propositions): Every proposition about the future has a defined truth value; No proposition about the future has a defined truth value; Some propositions about the future have a defined truth value and some do not. The last is my view.
Here is a statement for which I suspect the truth value is fixed: “The sun will rise within the next twenty-four hours.” Here is another: “The Liberal Democratic Party will not win an overall majority in the 1997 British General Election.” Please note that the first case is a scientific statement, and implies that it is not merely a remote possibility, but in principle impossible, that random destruction of matter (which is possible) should destroy the sun before dawn tomorrow. Thus it is a strong claim about the future, and one which some physicists would dispute. Nonetheless I suspect they would be wrong. The second statement involves human decisions. Some people would like to think that millions of people could yet change their minds and vote for the Liberals. I am saying that this is not merely unlikely, but impossible. I would not make the same claim about an election after, say, 2001. Now note immediately a property of statements about the future under partial determinism. I claim that the truth values of these two statements are fixed. That is a strong claim. I am not merely predicting that the sun will rise within the next twenty-four hours. I am not just saying that this is overwhelmingly likely. I am saying that this is already true.
Now to some statements which I suspect are not fixed: “There will be a hurricane in North Korea in the year 3240 AD.” and “Bill Clinton will have porridge for breakfast on December 4 1999.” Now I could be wrong about either of these. Perhaps I need the year 324444 AD for the North Korea Hurricane question to be undefined. Perhaps Bill Clinton is allergic to porridge and never eats it. I don’t know. But these are the sort of statements about the future that I suspect are undefined. Again the first statement is a scientific one. What I am suggesting is that quantum events whose resolution is as yet fundamentally undefined (as shown by the Bell Theorem) could, given long enough, through minor perturbations create the well-known butterfly effect upon the weather. Thus the truth value of this macro weather statement is, as yet, fundamentally undefined. I do not believe that the same can be said of hurricanes which will strike tomorrow, or even next week. (There are other mechanisms which might make the weather undefined quite separately from quantum events, of course, but quantum events suit my purposes here.) The second case again involves human choices. Perhaps Bill Clinton will be offered a genuine choice for breakfast that morning, or perhaps his breakfast will be imposed by purchasing decisions the previous week (e.g. they might have run out of all other cereals and he just won’t feel like eggs that morning) but either way I am suggesting that what he will have for breakfast is not yet defined.
Now to something rather pleasing one can do with partial determinism. Consider prophecy. Some people claim to be psychics or seers or prophets, and to know the future. Such people are often mocked by being asked questions like “So who’s going to win the 3.20 at Newmarket?” or “So why haven’t you won the Lottery, then?” Even when prophecies seem to be fulfilled (e.g. much of the book of Daniel) there is a decidedly vague sense about the prophecies. Answers often given about this vagueness include “Well, that is all God revealed” or “To tell people more would be dangerous” or “The disciplines of my occult art forbid me from dabbling in the Lottery.” Partial determinism offers a rather more straightforward solution. Prophecy will always be vague because the future is only vaguely defined. Even the greatest prophet might not be able to win the Lottery because its result may not be defined.
What of God’s Omniscience? Well, under partial determinism an Omniscience God would know everything there is to be known, and so would know the value of every truth function and know the likelihood of each resolution for all undefined truth functions.
This leads us into one of the classic arguments against partial determinism (or against total indeterminism). Some people believe (or at least believe that they believe) that God is outside time and can observe our future as if it were our past. He can see everything that will ever happen, or has ever happened. Since God can see all the truth values for every proposition throughout time, all their values must be defined.
Now I don’t believe that any part of this is coherent, but for now I shall restrict myself to showing that it is irrelevant. In the argument above it was stated that God is outside time. But ‘is’ is a word in the present tense. So presumably, since God is not supposed to be inside time, and ‘God will be outside time’ and ‘God was outside time’ don’t seem any more promising, something else must be meant. If something else entirely is meant, so the argument is not supposed to be that God, at the present, can see all the truth values, then that’s enough for me now. I just want to claim that at the present, some truth values are defined and some are not. Perhaps someone will claim that what is meant is that ‘God was outside time, God is outside time, and God will be outside time’. Inspiring though I am sure this statement is, it does not get us anywhere. To say that God was outside time, just means that at some point in the past, it was correct to say ‘God is outside time’, which, if interpreted temporally, is just a flat contradiction. Now this may seem unfair. There is a plausible sense in which one could use the predicate ‘is outside time’. For example, one might say ‘Love is outside time’, which is presumably to say that Love does not depend on any particular cultural or temporal context. Love is Love is Love, as it were. Or Love is eternal. Similar sentiments might be expressed about Courage or Wisdom. Now if that is what someone means by ‘God is outside time’, then fine. However, it should be observed that this makes it entirely the wrong sort of statement to use in arguing against partial determinism. As I said above, I just want to claim that at the present, some truth values are defined and some are not, and if the argument is not supposed to be that God, at the present, can see all the truth values, then it is not an argument against me.
Someone has argued against me that the question of whether the truth values of propositions about the future are all defined is a separate matter from whether it is the current state of things which defines them. That is, to accept that all the truth values of propositions about the future are defined is not to believe in determinism. I accept that logically there are two questions, but I reject the claim that they are separate questions. If it is not the current state of things that gives the propositions about the future their truth values then what is it? Perhaps some people reserve the term ‘determinism’ for the view that the state of the universe as understood by current physics (and some contiguous development of it) determines all future states. But I would use ‘determinism’ in a slightly wider sense, for the claim that it is the current state of things, including the physical state of the universe, the nature and decisions of gods, and anything else which has happened so far, which defines all futures states of things. Thus, for example, ‘determinism’ would include ‘predestination’. But what is it supposed to mean to claim that the truth value of a proposition about the future is defined but it is not the current state of things which defines it? In what sense is this a truth value?
What of the other two possible points of view? Some people seem to feel that Determinism is obviously correct, in fact so obviously correct that it is not a theory in need of defence. Thus the elegance or power of any alternative is irrelevant. What would be required is an argument against Determinism, and not just an argument which might offer some undermining of Determinism, but one which is so persuasive and obvious that it is irresistible. Thus such people are claiming that the truth of Determinism is as obvious as the whiteness of snow or the redness of blood. I find this view most peculiar and can only conclude that its adherents are suffering from a diet of too much Classical and Relativistic Physics and too little casual living. How can anyone claim that it is overwhelmingly obvious that no-one ever makes a genuine decision, that nothing random ever happens, and that the future has no status different from that of the past? Surely even if these suggestions are coherent (which they most emphatically are not!) then they are profoundly counter-intuitive and as far from obvious as it is possible to be! In any event, Determinism is analytically false. That is, it does not have the status of a theory, since it not the sort of thing that could be proved by any evidence. It is not merely unlikely. It is completely impossible.
Surely the most likely start point is actually that nothing in the future is defined, and the interesting thing to do is to show how things could be otherwise. I consider it a great wonder that the tentacles of the present can reach into the future, but I believe that it is likely that they do. Why do I consider that the natural (though incorrect) intuition is that the future is totally undefined? At its most basic, the instict is that what has happened cannot be changed, but the future is precisely what can be changed. Time is an ordering on events. One attractive ordering relation is through causality (with essentially an unrestricted version of Einstein’s definition of time). Event B precedes event C but comes after event A if event B could, in principle, influence event C, but could not, in principle, influence event A. If events X and Y could not, even in principle, influence each other, then it is tempting to say that they are simultaneous. But this last claim seems to result in the rejection of partial determinism. Suppose I believe that the sun’s rising tomorrow is defined. Then nothing that happens today (outside fixed elements in the causal chain which leads to the sun’s rising) could, even in principle, change that. But when the sun rises tomorrow that event will not be able to change anything that happens today. So it seems that if partial determinism were true then everything that happens today would be, in some sense, simultaneous with the sun’s rising tomorrow. Thus the sun’s rising would not be an event in the future which is already defined today, but rather an event which is somehow already occurring today.
Is this argument flawed? or is it a powerful argument against partial determinism? In fact, neither! I take this argument on the chin, and claim instead that this is the great paradox of partial determinism: some events in the future have, in a sense, already happened. That is precisely what partial determinism is claiming. But can we go one step further, and make the claim of Determinism: that all events in the future have, in some sense, already happened? No! For this is to reject the existence of the future entirely. The future is precisely that set of times where not every well formed proposition has a defined truth value. To accept Determinism is to say that everything has already happened, but that is to put everything in the past and reject the existence of the future, which is obviously nonsense.
That will do for now. Any comments?