Notes on Carl Hoefer's "Freedom from the Inside Out" in C. Callender, ed., Time, Reality & Experience (Cambridge: Cambridge University Press, 2002, pp. 201–222).
Comments in black. Quotations in grey.
The very 'timelessness' of the 4-D block (in an A-series sense [of 'time']) leaves us free to reject the customary view that past events determine present choices. From the B-series perspective there is no reason to think of past --> future determination as more important or real than future --> past determination. And, even more to the point, one can equally view a set of events in the middle as determiners of both past and future events.
This is exactly what we should do.Our free actions, intentions, thoughts, etc., in the middle of the block universe, are part of what determines how the rest of the block shall be. (205)
In order to make the point vividly, Hoefer first discusses a Newtonian-style determinism. Newton's laws are time-reversal invariant, which guarantees also that they are bi-directionally deterministic to the extent that they are deterministic at all (which is not much - but never mind, use special relativity instead). But time-reversal invariance is not required for bi-directional determinism. For example, Hoefer says, QM is not time-reversal invariant but under a Bohmian interpretation, it is bi-directionally deterministic.
We are free to adopt these perspectives [of ourselves as determiners of our actions] because, quite simply, physics - including our postulated, perfected deterministic physics - is perfectly compatible with them. (207-8)
Determination is a logical relation; it does not imply causality.
The notion of past events determining and explaining future events, and the opposite direction (or an 'inside-out' direction) of explanation being somehow wrong or suspect, arises completely from an unholy marriage of A-series time with deterministic physics. The mistake is natural and understandable, because of the way the A-series dominates our lives and our thinking, especially our causal/explanatory thinking. It remains nevertheless a mistake. A deterministic physics gives us logical relations of determination, not a unique temporal relation of determination. In the block universe one can view a slice now, or a future slice, ... as logically determining the rest. These logical relations however are not in any interesting sense explanatory, nor even causal. (208)
Temporally asymmetric features of our world make it very unlikely that our free actions leave 'traces' on the past of a macro-level and repeatable nature. ... Here is an example. We know that if we want to have a drink be at a nice uniform 2 degrees C, we can start with our mixture at room temperature, add lots of ice, and wait. We don't have to worry about the drink getting hotter and the ice bigger. But suppose that on alternate days, the Second Law of thermodynamics switched temporal directions. Then on alternate days, we could cause a nice cool drink to have been present earlier, by adding ice to a room-temperature mixture. Here I am glossing over all the thorny problems about whether human bodies could live under such a reversal of thermodynamic asymmetry, and whether the perceived flow of time would not then reverse as well. (212)
What matters [about thermodynamic asymmetry] is that our free actions, while they may have logical consequences about the past ... do not have to be thought of as causally bringing about large-scale features of the past. (213)
The multiple realizability of thought and actions - for example, there are very many subtly different neural states of my brain that would count as intending to prepare a cool drink - implies that my action has a disjunctive (i.e., this or that or the other) set of logical consequences about the past. And the large speed of light, together with the small size of a human being (more specifically, the small region of spacetime constitutive of my action of preparing a cool drink) means that the logical consequences of my act stretch only a very short time into the past. These features - the disjunctive nature of the logical consequences, and their short reach into the past - are what I left out in the ellipsis above, quoting Hoefer.
Free action and causal completeness are compatible after all, and not in the (arguably) weak sense offered by traditional compatibilism. You have choices and you make them. Because of determinism, your choices (like any events) place constraints on what the world's history can be. But the direction of determination (and, for most free actions, correct explanation) is from your choices to the ways the physical world can be - both toward the past and the future. (221)
The very 'timelessness' of the 4-D block (in an A-series sense [of 'time']) leaves us free to reject the customary view that past events determine present choices. From the B-series perspective there is no reason to think of past --> future determination as more important or real than future --> past determination. And, even more to the point, one can equally view a set of events in the middle as determiners of both past and future events.
This is exactly what we should do.Our free actions, intentions, thoughts, etc., in the middle of the block universe, are part of what determines how the rest of the block shall be. (205)
In order to make the point vividly, Hoefer first discusses a Newtonian-style determinism. Newton's laws are time-reversal invariant, which guarantees also that they are bi-directionally deterministic to the extent that they are deterministic at all (which is not much - but never mind, use special relativity instead). But time-reversal invariance is not required for bi-directional determinism. For example, Hoefer says, QM is not time-reversal invariant but under a Bohmian interpretation, it is bi-directionally deterministic.
We are free to adopt these perspectives [of ourselves as determiners of our actions] because, quite simply, physics - including our postulated, perfected deterministic physics - is perfectly compatible with them. (207-8)
Determination is a logical relation; it does not imply causality.
The notion of past events determining and explaining future events, and the opposite direction (or an 'inside-out' direction) of explanation being somehow wrong or suspect, arises completely from an unholy marriage of A-series time with deterministic physics. The mistake is natural and understandable, because of the way the A-series dominates our lives and our thinking, especially our causal/explanatory thinking. It remains nevertheless a mistake. A deterministic physics gives us logical relations of determination, not a unique temporal relation of determination. In the block universe one can view a slice now, or a future slice, ... as logically determining the rest. These logical relations however are not in any interesting sense explanatory, nor even causal. (208)
Temporally asymmetric features of our world make it very unlikely that our free actions leave 'traces' on the past of a macro-level and repeatable nature. ... Here is an example. We know that if we want to have a drink be at a nice uniform 2 degrees C, we can start with our mixture at room temperature, add lots of ice, and wait. We don't have to worry about the drink getting hotter and the ice bigger. But suppose that on alternate days, the Second Law of thermodynamics switched temporal directions. Then on alternate days, we could cause a nice cool drink to have been present earlier, by adding ice to a room-temperature mixture. Here I am glossing over all the thorny problems about whether human bodies could live under such a reversal of thermodynamic asymmetry, and whether the perceived flow of time would not then reverse as well. (212)
What matters [about thermodynamic asymmetry] is that our free actions, while they may have logical consequences about the past ... do not have to be thought of as causally bringing about large-scale features of the past. (213)
The multiple realizability of thought and actions - for example, there are very many subtly different neural states of my brain that would count as intending to prepare a cool drink - implies that my action has a disjunctive (i.e., this or that or the other) set of logical consequences about the past. And the large speed of light, together with the small size of a human being (more specifically, the small region of spacetime constitutive of my action of preparing a cool drink) means that the logical consequences of my act stretch only a very short time into the past. These features - the disjunctive nature of the logical consequences, and their short reach into the past - are what I left out in the ellipsis above, quoting Hoefer.
Free action and causal completeness are compatible after all, and not in the (arguably) weak sense offered by traditional compatibilism. You have choices and you make them. Because of determinism, your choices (like any events) place constraints on what the world's history can be. But the direction of determination (and, for most free actions, correct explanation) is from your choices to the ways the physical world can be - both toward the past and the future. (221)
Notes on Jenann Ismael's talk "On why we see the past as fixed and the future as something we can bring about by will: the view through the lenses of physics"
Ismael's talk is available through this website Paraphrases in blue.
The physicist inhabits a four-dimensional block universe. There is no ontological distinction between past, present, and future events in this universe. There are internal relations among events in the spacetime manifold, captured by the light cone structure, along which information and causal influence propagates.
Ismael compares and contrasts the perspective of everyday experience. When a decision-maker looks into the past, she sees a domain of fixed fact about which she has accumulated a large and growing body of information. When she looks into the future, she sees a number of ways things could go, depending on what she chooses, and her choice is guided by her relative valuation of those possibilities. Seen through her eyes, the decision process itself transforms a multiplicity of possibilities into a single actuality.
Let's take a break from listening to Ismael and raise a worry that many other philosophers have raised: to wit, isn't there a contradiction here? If we accept the block universe interpretation of physics, don't we have to declare that the perspective of everyday experience is an illusion? In a word, no. Not only is the everyday experience exactly what one would expect based on the physics of human life, but in the broad outlines just canvassed, it's actually correct. Back to Ismael.
Take the present macroscopic state of the world ,and changes to it that correspond to actions we are thinking of taking. Propagate these changes into both the past and future, according to the laws of physics. We find that these changes in the present produce large differences in the future but leave the macroscopic states of the past largely untouched. Events in a low entropy environment leave macroscopic records of their occurrence in their future (the future light-cone of the event) but not their past. (Ismael attributes this pair of points to David Albert.) The asymmetry comes from thermodynamics plus the fact that our universe's past is a much lower-entropy state than its present, which in turn is lower-entropy than the future. This is not just a point about agents' knowledge or ignorance; it is an objective reality that at the macroscopic level, changes propagate into the future but not the past. It's not just that we don't know as much about the future as we do about the past, that makes us (properly!) see the future as more open to us. This asymmetry in our knowledge is also explained by thermodynamic asymmetries, just as the practical asymmetry is, but the practical asymmetry is not dependent on the knowledge asymmetry.
In contrasting our attitudes toward different locations in time versus different locations in space, we might say that different parts of space are "there already" waiting to be experienced. Or we might say they are "there anyway" regardless of how we represent them as being. The latter phrase is more helpful, because it allows us to draw the comparison to the future without begging any questions. Obviously the future isn't there already.
To most facts - the price of tea in China, what Vladimir Putin had for breakfast - we take a passive, epistemic attitude. The epistemic attitude presupposes a separation of what is being represented and the act of representing it. That separation is absent when one is representing one's own judgments and decisions. In those cases there isn't anything "there to be represented" before the judgment or decision is made. There isn't anything that's there anyway. Sincere decisions of the form "I have decided to X" are self-validating statements. They are like promises - e.g. "I promise to return it tomorrow" - in making true the sentences they express. Had I not said "I promise to return it" there would be no such promise, but the moment I say it, there is such a promise, so the statement "I promise" makes itself true. Philosophers have a name for such sentences: they are called performatives. There is no way of letting your beliefs about these thing be led by the facts about them when the facts are created by the very affirmations in question. There is a certain degeneracy in your relation to statements about what you will decide. We could call the result "choice-dependent ignorance". Along with the choices themselves, any features of the space-time manifold that depend on these choices are not fixed independently of your activity.
The asymmetric manner in which macroscopic changes propagate into the past and future, combined with the self-referential nature of statements about one's own decisions, combine to explain why we think of the past as a domain of purely epistemic uncertainty and the future as a domain over which we exert choices. They explain these thoughts without explaining them away. The past we care about - the macroscopic past - really is fixed, i.e. "there anyway" regardless of what we decide. The future we care about really is not. A decision maker can't stabilize her beliefs about the future until she stabilizes her choices. And she can't stabilize her beliefs about her choices until she makes them. Her choices are ultimately and inalienably up to her, as a trivial logical deduction has shown, based on their self-referential character.
It might be objected that, even though I have choice-dependent uncertainty about my future decisions and hence large swaths of the future, the openness of the future (says the objector) is an illusion. It is only because I am ignorant of the future, says the objector, that I see my choices as having an impact. If I had knowledge of the future, in the way that I have memories of the past, says the objector, the domain of choice-dependence would shrink to include nothing but the choices themselves.
Ismael's reply is that this gets things exactly backwards. It isn't ignorance of the future that makes for choice-dependence, and it isn't knowledge of the macroscopic past that makes it choice-independent. Rather, it is the thermodynamic asymmetry and its physical consequences for propagation of macroscopic changes, that makes the past for-all-practical-purposes "fixed". If it were not for the fact that the macroscopic past is immune to present-day macroscopic changes, the past would not be fixed either. And in that case the epistemic attitude would be inappropriate to the past. The epistemic attitude depends on non-openness, not vice versa.
In case you didn't figure it out yet, I think both Carl Hoefer and Jenann Ismael are right, despite the nearly-conflicting language they occasionally use. (But not actually conflicting: Hoefer says we can and should view the past as determined by our present choices; Ismael says the macroscopic past is fixed. But the macroscopic past is not all there is to the past, and its microscopic details are not independent of our present choices.) What's the takeaway?
Some self-styled scientific determinists like Sam Harris argue that our sense of free will is illusory. Their arguments always equivocate, however, between scientific conceptions of causality and everyday human-centered conceptions. In actual scientific deterministic theories, like Bohmian QM, determination goes both ways: from an event to earlier events, and also to later ones. In our human-centered concept, an agent makes a change in the present, typically knows at least to some degree how the change propagates into the future, and does what it does in the present precisely in order to control (to some degree) the future. What the "scientific determinist" claims boils down to this: because the past controls us, no one controls anything. The dragon of Control swallows its own tail, and supposedly, our free will along with it. That is one neat magic trick!
We only need to ask which sort of determination the past "exerts" on us. Is it scientific determination, i.e. the mutual inter-derivability of descriptions of past and present? Then no problem: back atcha, past! We determine the past in that sense, too. Or is it the human-centered, everyday-experience-based idea of causal control, which the past is supposed to exert on us? Then sorry, not allowed: that sort of control is being put into question. You cannot lash us with a tail that you are busy swallowing. The key to our reply is to notice that the "immutability of the past" is strictly a function of the everyday, human-centered idea of causal control. In the cold, dry scientific equations, it is nowhere to be found. It's only because we don't care about the microscopic details of the past that we (reasonably, for all practical purposes) can regard the past as fixed.
The physicist inhabits a four-dimensional block universe. There is no ontological distinction between past, present, and future events in this universe. There are internal relations among events in the spacetime manifold, captured by the light cone structure, along which information and causal influence propagates.
Ismael compares and contrasts the perspective of everyday experience. When a decision-maker looks into the past, she sees a domain of fixed fact about which she has accumulated a large and growing body of information. When she looks into the future, she sees a number of ways things could go, depending on what she chooses, and her choice is guided by her relative valuation of those possibilities. Seen through her eyes, the decision process itself transforms a multiplicity of possibilities into a single actuality.
Let's take a break from listening to Ismael and raise a worry that many other philosophers have raised: to wit, isn't there a contradiction here? If we accept the block universe interpretation of physics, don't we have to declare that the perspective of everyday experience is an illusion? In a word, no. Not only is the everyday experience exactly what one would expect based on the physics of human life, but in the broad outlines just canvassed, it's actually correct. Back to Ismael.
Take the present macroscopic state of the world ,and changes to it that correspond to actions we are thinking of taking. Propagate these changes into both the past and future, according to the laws of physics. We find that these changes in the present produce large differences in the future but leave the macroscopic states of the past largely untouched. Events in a low entropy environment leave macroscopic records of their occurrence in their future (the future light-cone of the event) but not their past. (Ismael attributes this pair of points to David Albert.) The asymmetry comes from thermodynamics plus the fact that our universe's past is a much lower-entropy state than its present, which in turn is lower-entropy than the future. This is not just a point about agents' knowledge or ignorance; it is an objective reality that at the macroscopic level, changes propagate into the future but not the past. It's not just that we don't know as much about the future as we do about the past, that makes us (properly!) see the future as more open to us. This asymmetry in our knowledge is also explained by thermodynamic asymmetries, just as the practical asymmetry is, but the practical asymmetry is not dependent on the knowledge asymmetry.
In contrasting our attitudes toward different locations in time versus different locations in space, we might say that different parts of space are "there already" waiting to be experienced. Or we might say they are "there anyway" regardless of how we represent them as being. The latter phrase is more helpful, because it allows us to draw the comparison to the future without begging any questions. Obviously the future isn't there already.
To most facts - the price of tea in China, what Vladimir Putin had for breakfast - we take a passive, epistemic attitude. The epistemic attitude presupposes a separation of what is being represented and the act of representing it. That separation is absent when one is representing one's own judgments and decisions. In those cases there isn't anything "there to be represented" before the judgment or decision is made. There isn't anything that's there anyway. Sincere decisions of the form "I have decided to X" are self-validating statements. They are like promises - e.g. "I promise to return it tomorrow" - in making true the sentences they express. Had I not said "I promise to return it" there would be no such promise, but the moment I say it, there is such a promise, so the statement "I promise" makes itself true. Philosophers have a name for such sentences: they are called performatives. There is no way of letting your beliefs about these thing be led by the facts about them when the facts are created by the very affirmations in question. There is a certain degeneracy in your relation to statements about what you will decide. We could call the result "choice-dependent ignorance". Along with the choices themselves, any features of the space-time manifold that depend on these choices are not fixed independently of your activity.
The asymmetric manner in which macroscopic changes propagate into the past and future, combined with the self-referential nature of statements about one's own decisions, combine to explain why we think of the past as a domain of purely epistemic uncertainty and the future as a domain over which we exert choices. They explain these thoughts without explaining them away. The past we care about - the macroscopic past - really is fixed, i.e. "there anyway" regardless of what we decide. The future we care about really is not. A decision maker can't stabilize her beliefs about the future until she stabilizes her choices. And she can't stabilize her beliefs about her choices until she makes them. Her choices are ultimately and inalienably up to her, as a trivial logical deduction has shown, based on their self-referential character.
It might be objected that, even though I have choice-dependent uncertainty about my future decisions and hence large swaths of the future, the openness of the future (says the objector) is an illusion. It is only because I am ignorant of the future, says the objector, that I see my choices as having an impact. If I had knowledge of the future, in the way that I have memories of the past, says the objector, the domain of choice-dependence would shrink to include nothing but the choices themselves.
Ismael's reply is that this gets things exactly backwards. It isn't ignorance of the future that makes for choice-dependence, and it isn't knowledge of the macroscopic past that makes it choice-independent. Rather, it is the thermodynamic asymmetry and its physical consequences for propagation of macroscopic changes, that makes the past for-all-practical-purposes "fixed". If it were not for the fact that the macroscopic past is immune to present-day macroscopic changes, the past would not be fixed either. And in that case the epistemic attitude would be inappropriate to the past. The epistemic attitude depends on non-openness, not vice versa.
In case you didn't figure it out yet, I think both Carl Hoefer and Jenann Ismael are right, despite the nearly-conflicting language they occasionally use. (But not actually conflicting: Hoefer says we can and should view the past as determined by our present choices; Ismael says the macroscopic past is fixed. But the macroscopic past is not all there is to the past, and its microscopic details are not independent of our present choices.) What's the takeaway?
Some self-styled scientific determinists like Sam Harris argue that our sense of free will is illusory. Their arguments always equivocate, however, between scientific conceptions of causality and everyday human-centered conceptions. In actual scientific deterministic theories, like Bohmian QM, determination goes both ways: from an event to earlier events, and also to later ones. In our human-centered concept, an agent makes a change in the present, typically knows at least to some degree how the change propagates into the future, and does what it does in the present precisely in order to control (to some degree) the future. What the "scientific determinist" claims boils down to this: because the past controls us, no one controls anything. The dragon of Control swallows its own tail, and supposedly, our free will along with it. That is one neat magic trick!
We only need to ask which sort of determination the past "exerts" on us. Is it scientific determination, i.e. the mutual inter-derivability of descriptions of past and present? Then no problem: back atcha, past! We determine the past in that sense, too. Or is it the human-centered, everyday-experience-based idea of causal control, which the past is supposed to exert on us? Then sorry, not allowed: that sort of control is being put into question. You cannot lash us with a tail that you are busy swallowing. The key to our reply is to notice that the "immutability of the past" is strictly a function of the everyday, human-centered idea of causal control. In the cold, dry scientific equations, it is nowhere to be found. It's only because we don't care about the microscopic details of the past that we (reasonably, for all practical purposes) can regard the past as fixed.