E-033 SEP HDET - Determinism Hard (Thesis 2 Excerpt)

Exact excerpt

In all this, we have been presupposing the common-sense Newtonian framework of space and time, in which the world-at-a-time is an objective and meaningful notion. Below when we discuss determinism in relativistic theories we will revisit this assumption.
### 2.3 Thereafter
For a wide class of physical theories (i.e., proposed sets of laws of nature), if they can be viewed as deterministic at all, they can be viewed as _bi-directionally_ deterministic. That is, a specification of the state of the world at a time _t_ , along with the laws, determines not only how things go _after t_ , but also how things go _before t_. Philosophers, while not exactly unaware of this symmetry, tend to ignore it when thinking of the bearing of determinism on the free will issue. The reason for this is that, as noted just above, we tend to think of the past (and hence, states of the world in the past) as _sharp and determinate_ , and hence _fixed and beyond our control_. Forward-looking determinism then entails that these past states—beyond our control, perhaps occurring long before humans even existed—determine everything we do in our lives. It then seems a mere curious fact that it is equally true that the state of the world _now_ determines everything that happened in the past. We have an ingrained habit of taking the direction of both causation and explanation as being past → present, even when discussing physical theories free of any such asymmetry. We will return to this point shortly.
Another point to notice here is that the notion of things being determined _thereafter_ is usually taken in an unlimited sense—i.e., determination of all future events, no matter how remote in time. But conceptually speaking, the world could be only _imperfectly_ deterministic: things could be determined only, say, for a thousand years or so from any given starting state of the world. For example, suppose that near-perfect determinism were regularly (but infrequently) interrupted by spontaneous particle creation events, which occur only once every thousand years in a thousand-light-year-radius volume of space. This unrealistic example shows how determinism could be strictly false, and yet the world be deterministic enough for our concerns about free action to be unchanged.
### 2.4 Laws of nature
In the loose statement of determinism we are working from, metaphors such as “govern” and “under the sway of” are used to indicate the strong force being attributed to the laws of nature. Part of understanding determinism—and especially, whether and why it is metaphysically important—is getting clear about the status of the presumed laws of nature.
In the physical sciences, the assumption that there are fundamental, exceptionless laws of nature, and that they have some strong sort of modal force, usually goes unquestioned. Indeed, talk of laws “governing” and so on is so commonplace that it takes an effort of will to see it as metaphorical. We can characterize the usual assumptions about laws in this way: the laws of nature are assumed to be _pushy explainers_. They _make things happen in certain ways_ and, by having this power, their existence lets us _explain_ why things happen in certain ways. (For a defense of this perspective on laws, see Maudlin (2007)). Laws, we might say, are implicitly thought of as the _cause_ of everything that happens. If the laws governing our world are deterministic, then in principle everything that happens can be explained as following from states of the world at earlier times. (Again, we note that even though the entailment typically works in the future→past direction also, we have trouble thinking of this as a legitimate _explanatory_ entailment. In this respect also, we see that laws of nature are being implicitly treated as the causes of what happens: causation, intuitively, can only go past→future.)
Interestingly, philosophers tend to acknowledge the apparent threat determinism poses to free will, even when they explicitly reject the view that laws are pushy explainers. Earman (1986), for example, advocates a theory of laws of nature that takes them to be simply the best system of regularities that systematizes all the events in universal history. This is the Best Systems Analysis (BSA), with roots in the work of Hume, Mill and Ramsey, and most recently refined and defended by David Lewis (1973, 1994) and by Earman (1984, 1986). (cf. entry on [laws of nature](https://plato.stanford.edu/entries/laws-of-nature/)). Yet he ends his comprehensive _Primer on Determinism_ with a discussion of the free will problem, taking it as a still-important and unresolved issue. _Prima facie_ this is quite puzzling, for the BSA is founded on the idea that the laws of nature are ontologically derivative, not primary; it is the events of universal history, as brute facts, that make the laws be what they are, and _not_ vice-versa. Taking this idea seriously, the actions of every human agent in history are simply a part of the universe-wide pattern of events that determines what the laws are for this world. It is then hard to see how the most elegant summary of this pattern, the BSA laws, can be thought of as determiners of human actions. The determination or constraint relations, it would seem, can go one way or the other, not both.
On second thought, however, it is not so surprising that broadly Humean philosophers such as Ayer, Earman, Lewis and others still see a potential problem for freedom posed by determinism. For even if human actions are part of what makes the laws be what they are, this does not mean that we automatically _have_ freedom of the kind we think we have, particularly freedom _to have done otherwise_ given certain past states of affairs. It is one thing to say that everything occurring in and around my body, _and_ everything everywhere else, conforms to Maxwell’s equations and thus the Maxwell equations are genuine exceptionless regularities, and that because they in addition are simple and strong, they turn out to be laws. It is quite another thing to add: thus, I might have chosen to do otherwise at certain points in my life, and if I had, then Maxwell’s equations would not have been laws. One might try to defend this claim—unpalatable as it seems intuitively, and Lewis (1981) does this. But it does not follow directly from a Humean approach to laws of nature, and Loewer (2020, Other Internet Resources) defends a different Humean compatibilism, to which we will return in section 6.
A second important genre of theories of laws of nature holds that the laws are in some sense _necessary_. For any such approach, laws are just the sort of pushy explainers that are assumed in the traditional language of physical scientists and free will theorists. But a third and growing class of philosophers holds that (universal, exceptionless, true) laws of nature _simply do not exist_. Among those who hold this are influential philosophers such as Nancy Cartwright, Bas van Fraassen, and John Dupré. For these philosophers, there is a simple consequence: determinism is a false doctrine. As with the Humean view, this does not mean that concerns about human free action are automatically resolved; instead, they must be addressed afresh in the light of whatever account of physical nature without laws is put forward. See Dupré (2001) for one such discussion.
### 2.5 Fixed