Atención primaria a los afectados en el terremoto de Haití

Despite suggesting that we amend the BSA to include a distinction between the ICH and DH, Hall suggests that there is a problem with doing so.48 _{The concern is that}

once we have made this distinction, it is hard to see exactly why scientists ought to care about the laws generated by the BSA. That is worrying, since scientists quite clearly do try to find what the laws are! Let us examine what the problem is supposed to be. Anti-Humean views that do not attempt to reduce the laws have a straightforward way to explain why scientists ought to care about them. If the laws genuinely do have a role to play in guiding and constraining what happens at the world, then any account that correctly identifies them has picked up on a central feature of the world that has a deep relation to the nonmodal facts. Conversely, any account which ignores them fails to pick up on an important aspect of the way the world is. It is easy to see, therefore, why scientists should care about finding anti- Humean laws since, by doing so, they uncover a vitally important part of the world’s structure. If we have any desire to find out about the world around us, we ought to be interested in laws like these. In short, this is why anti-Humeans have an easy time explaining why the laws are, in Hall’s phrase, distinctively appropriate targets of scientific inquiry (DATSIs).

The Humean story must be somewhat different, since they must deny that sort of deep metaphysical connection between laws and nonmodal facts. Humean laws are a useful part of our investigation into the world’s nonmodal facts. We do not use

experiments to discover patterns that point to something behind the scenes that directs the worldly phenomena; there is no director behind the curtain! The mosaic and its patterns are not just all that we can observe, they are all that is in the picture at all. The role that laws play in our scientific investigations must be rather different. The usual evocative metaphor that suggest what this role is has been given by Beebee:

So the idea is something like this. Suppose God wanted us to learn all the facts there are to be learned. (The Ramsey-Lewis view is not an epistemological thesis but I’m putting it this way for the sake of the story.) He decides to give us a book – God’s Big Book of Facts – so that we might come to learn its contents and thereby learn every particular matter of fact there is. As a first draft, God just lists all the particular matters of fact there are. But the first draft turns out to be an impossibly long and unwieldly manuscript, and very hard to make any sense of – it’s just a long list of everything that’s ever happened and will ever happen. We couldn’t even come close to learning a big list of independent facts like that. Luckily, however (or so we hope), God has a way of making the list rather more comprehensible to our feeble, finite minds: he can axiomatize the list. That is, he can write down some universal generalizations with the help of which we can derive some elements of the list from others. This will have the benefit of making God’s Big Book of Facts a good deal shorter and also a good deal easier to get our rather limited brains around.49

This is a rather pragmatic role, for it suggests that the only reason that we care about what the laws are is that they help us to learn more about the world. That they are laws is, on its own, not sufficient to make us care about them. Rather, we care because they are useful to us (the contrast here with the more privileged anti- Humean laws becomes clear as there is reason to care about them beyond merely gathering nonmodal information in an efficient manner). The anti-Humean laws are DATSIs due to their metaphysical nature, while the opposite is true for Humean laws. Those laws must be DATSIs for some independent reason – the passage from Beebee suggesting the reason is that they are particularly useful in summarising the world’s nonmodal facts – and their lawfulness is entirely dependent on them playing this role.

Returning to Hall’s worry, it appears that the standards of strength used by scientists come into tension with the Humean claim that we care about laws due to their summarising role. The best system of laws will more recognisably be a DATSI if it is best because it is especially good at summarising nonmodal facts. After all, if finding out such facts is the purpose of scientific inquiry, Humeans will have a straightforward story to tell about why scientists ought to care about the best summary of those facts. This points towards Lewis’ suggested way in which the virtue of strength should be evaluated: the more possible worlds that a system rules out as being actual, the more informative it is about the actual world’s nonmodal facts. But if this is the case, it is no longer clear why scientists should look for their initial conditions to be as non-specific to our world as possible. The more uninformative the ICH, the less the system as a whole will rule out possible worlds. So if we aim to adopt the standards used by actual scientists, then why should we care about the laws generated by the Humean account? Once we make the split between the ICH and DH in the BSA, Hall’s worry is that we can no longer explain why the resulting laws are DATSIs.

This can be expressed in the form of a dilemma. On the first horn, we look to the practices of scientists to inform the standards by which candidate systems are judged. But then it becomes a mystery as to why we ought to care about the laws the best system will generate. On the second horn, we stick to Lewis’ original standards and so explain why it is that laws are DATSIs. But then we struggle to give a reason why scientists appear to be using rather different standards in their investigations. As Hall nicely puts it, this choice ‘between a guilty intellectual conscience and insane revisionism is not a happy one.’50

The dilemma, however is a false one. While those may be the two available options available if one accepts this way of setting up the problem, there is a third option: reject this characterisation of scientific inquiry and the roles that laws play in it. It is fair to expect Humeans to give an account of laws that allows us to see why scientists might care about them. It is also right to require that if this Humean account shows

why laws are DATSIs, it does so for reasons beyond their lawhood alone. But what Humeans can reject is the suggestion that science is concerned only with the accumulation of information regarding the world’s nonmodal facts. Suggestions as to what else science might be aiming at have been made:

All science is a search for unification … Finding hidden links between seemingly disparate phenomena is what makes the scientific method so powerful and compelling. The distinctive feature of science is that it is both broad and deep: broad in the way that it tackles all physical phenomena and deep in the way it weaves them, economically, into a common explanatory scheme requiring fewer and fewer assumptions.51

[T]he important thing in science is not so much to obtain new facts as to discover new ways of thinking about them.52

The aim of science is to seek the simplest explanations of complex facts.53

That we wish to discover more of our world’s nonmodal facts seems difficult to deny. But the scientific project is not solely concerned with listing these facts. It is also concerned with issues of explanation and – more controversially – understanding. Stating some collection of facts is one thing, showing how they fit together and relate to one another is a step beyond that. Not for nothing are scientific laws expected to play a role in scientific explanations. If I am able to appreciate that a given fact fits into a general pattern, I have gained a different kind of knowledge to that which I would have if I was merely aware of the fact and not its wider significance. One way in which we get a grip on explanations is through thinking about counterfactuals and difference-making.54 _{If I had performed some other action, how might things have}

developed differently? If the world’s initial conditions were tweaked just so, would it still have been hospitable to lifeforms like ourselves? If Isildur had cast the One Ring into the fires whence it came, what kind of life would Frodo have lived? In

51 _{Davies (2006) p. 103.}

52 _{This is attributed to William Bragg by Hydén (1969) p. 115.} 53 _{Whitehead (1920) p. 163.}

54 _{Although the association between explanation and understanding is not without}

controversy, this is closely related to discussions on the relationship between explanation and counterfactuals. The most well-known defence of the claim that (causal) explanations are a matter of seeing what would be different under a counterfactual is Woodward (2003).

considering such questions, we need to grasp how different facts relate to each other in order to formulate any kind of reasonable response.

It is with this sort of aim in mind that we can say why scientists might care about the laws generated by a BSA that incorporates an ICH/DH split. Informativeness of the Dynamic Hypothesis is clearly a virtue, as the more deterministic the laws are, the better they pick out our world. Accumulation of nonmodal facts may not be the only aim of science, but it is still an aim. The reason that uninformativeness of the initial conditions is a virtue is that it plays into our counterfactual reasoning. If a maximally specific set of initial conditions was taken to be physically necessary, it would be very difficult to understand how any phenomenon depended on any other. Any difference in set-up would require that we consider physically impossible worlds when evaluating counterfactuals. But considering differences is a large part of how we get an explanatory grip on (and perhaps an understanding of) the world. A theory’s ability to contribute towards answering counterfactuals regarding alternative initial conditions is a significant part of its ability to provide explanations. Aiming for a less specific ICH lets a wider range of worlds count as relevantly like ours when we start to ask what things would be like if certain facts were different. The purpose of having uninformative initial conditions is to enable us to see that certain features of our particular world are not arbitrary. That this planet is home to creatures like us, or that there is a planet Earth in the first place, might well count as arbitrary: small changes in the boundary conditions could have led to different later results. But we can see how these differ from the patterns captured by the laws: that the planets should have orbits like the ones they in fact do is not arbitrary in the same way. In making every one of the world’s nonmodal facts count as physically necessary, a maximally specific ICH obliterates this difference. This is why a best system amended to include a split between the DH and the ICH should count as a DATSI. It plays a role in efficiently summarising the nonmodal facts at our world. It also helps us to understand how those facts fit together by supporting counterfactuals.

In tackling various issues that arise when we set out the regularity view, I have not tried to argue specifically for a single account that solves all of these issues in a way

that all of the participants in the debate would accept. If that’s the criterion for success, then I suspect that no such account is available. There are too many differences between starting presuppositions of the philosophers in question and their assessments of the relative upsides and downsides of each solution for that to be a reasonable goal. Happily, I don’t think that trying to provide that single account is necessary, given the goals of this thesis. What we need is a reasonably clear idea of the Humean approach to laws, and metaphysics more generally. That’s compatible with there being various accounts sitting together under the Humean umbrella. I leave it up to the individual Humeans as to which specific variation of the regularity account they find most palatable. In responding to Hall regarding what would make a system a DATSI, I have appealed to explanation. However, one might worry that Humean accounts of laws are unsuited to generate genuine explanations due to their lack of metaphysical ‘oomph’. The following chapter takes up this question in some detail.