Bel of any ordinary CEU theorem must be understood as being defined on some algebra of sets P defined on a space of possible worlds, W (or in the case of Savage-
3.4 Desiderata
We have seen three broad kinds o f complaints that have been raised against
OCR
and the positions which imply it. First o f all— and, I think, most importantly— it’s very plausible that credences and utilities ought to be kept metaphysically and con ceptually distinct from preferences. Having a credence o f v in P, in particular, is not
just a kind of preference state. There needs to be some wriggle room between the two kinds o f states; credences appear to give rise to preferences, but not with invar iable certainty, and not always through expected utility maximisation. Furthermore, credences seem to play other roles besides their role in the production o f prefer ences— for instance, they change in response to evidence— and this needs to be ac counted for in any adequate characterisation o f what it is to have credences. One of the central roles o f
Chapter 4
is to show that characterisational representationism can accommodate this lesson.The second kind o f complaint arises from the details o f the theorems which un derlie
CCR.
These decompose into two basic issues: first, whether ordinary agents satisfy (or come sufficiently close to satisfying) the relevant theorem s’ preference conditions; and second, whether the ensuing models o f their credences, utilities, and decision-making process are plausible.Supposing that we were to remove CEU theorems from consideration, the obvi ous alternative for characterisational representationism would be to appeal to some NCU theorem. NCU theorems are, for the most part, explicitly designed to capture the preference patterns o f ordinary agents, and many o f them allow for /7cw-proba- bilistic credence functions. Typically, NCU theorems achieve this with weaker preference conditions than those found in CEU theorems— that is, preferences
which satisfy the CEU conditions will also satisfy the NCU conditions, but not vice versa. By setting weaker and more realistic preference conditions and allowing for a broader range o f representations, NCU theorems should look like a very attractive place to search for a firmer basis for characterisational representationism.
O f course, not any NCU theorem will do— we need a theorem with the right properties. To close this chapter, then, I want to say in more general terms what
kinds o f features a representation theorem should have, i f it is to underlie a more plausible version o f characterisational representationism. I will begin with a very schematic discussion o f some basic conditions on any characterisation o f credences and utilities.
Any minimally realist account o f what it takes to have such-and-such credences and utilities can be put very schematically as follows:
S has credences 'Bel and utilities Ves iff S satisfies conditions N
Now, first o f all, for any plausible account it ought to be the case that:
Satisfiability
Ordinary agents generally satisfy conditions N
If Satisfiability is not satisfied, then the account is unable to explain how it is that ordinary agents have the credences and utilities that they do. Secondly, the account ought to be plausible:
Plausibility
The Bel and Ves assigned to S under conditions N are plausible models of S's cre dences and utilities, in the sense that they broadly coincide with our intuitions/em pirical data regarding what credences and utilities an ordinary agent would have in those conditions
If Plausibi lity is not satisfied, then we have good reason to think that the account is not picking out those intentional states which we understand to be credence and utility states, nor anything in the vicinity. Note that perfect fit with our intuitive
judgements is not required to satisfy this second condition: there is always some room to move away from what is intuitive, if such manoeuvres are well motivated.
Thirdly, the account should not be circular:
Non-Circularity
N ought to specifiable without reference to 5”s credences or utilities
If Non-Circularity is not satisfied, then the characterisation is obviously at least somewhat circular, requiring prior knowledge o f S’s credences and/or utilities be fore being able to specify what her credences and utilities are.
Furthermore, if the goal is to generate a fully naturalistic account, then the fol lowing should be satisfied:
Naturalisability
N ought to be specified by reference only to natural or readily naturalisable proper ties
Paradigm instances o f concepts which are not readily naturalisable include the se mantic, intentional, and other mental concepts— hence the focus on naturalising in- tentionality, rather than (say) the property o f being a teacup.
The advocate o f characterisational representationism seeks to make essential use o f a representation theorem in her characterisation of credences and utilities. Spe cifically, she thinks that the modelling schemes generated by such a theorem can tell us a great deal about what an ordinary agent’s credences and utilities are, and how she forms her decisions, given enough information about the agent’s prefer ences (in either the mentalistic or behavioural sense). As I will argue in Chapter 4, there need not be any simple and straightforward relationship between how an agent can be modelled according to the theorem and what her mental states actually are— CCR is not the only game in town— but there must nevertheless be a close relation ship between the modelling scheme and the mental facts o f the matter, i f the view is to count as an instance o f characterisational representationism.
Our three conditions, Satisfiability, Plausibility, and Non-Circularity, therefore, can be used to generate a number o f basic desiderata that we might want a repre sentation theorem to satisfy, if it is to provide a plausible foundation for the char- acterisational representationist’s project. Naturalisabi 1 ity, likewise, generates a fur ther desideratum for naturalisers. These desiderata are summarised in §3.4.5 below.
3.4.1 The theorem 's condition 's satisfiability
Given Satisfiability, it’s clear that a representation theorem will only be useful for the purposes o f characterisational representationism to the extent that its preference conditions are satisfied— or at least approximately satisfied— by ordinary agents, at least under appropriately specified conditions.
An absolutely minimal requirement, then, is that the theorem’s preference con ditions are (approximately) satisfiable. (In what follows, I will set aside the ‘ap proximately’ qualifier for ease o f reading.) As we will see in §5.2.1-2 and to a lesser extent §7.2.2, we should not take it for granted that the conditions placed on <*BOT, >> can be satisfied by any agent’s preference system. As noted in §2.4, the fact that <SO!P, >> is intended to represent a possible preference system is not sufficient reason to assume that it does so. Formally characterised, > and/or 3 0 T may have properties which would make no sense under the intended interpretation. In partic ular, > may end up being defined on a collection o f entities which bear no resem blance to what might reasonably be considered a set o f basic objects o f preference, under any conception o f ‘preference’.
Supposing, then, that the representation theorem’s conditions are satisfiable, we can consider whether the conditions are satisfied. Characterisational representa tionism, based on a given representation theorem T, is more plausible to the extent that T s preference conditions actually are satisfied by the average person on the street, at least under appropriately specified conditions. If no ordinary agent (in the right conditions) ever satisfies the T s conditions for representation, even approxi mately, then the theorem would seem to have nothing interesting to tell us about the credences and utilities o f ordinary agents.
To be sure, if some kind of idealised being were to satisfy the conditions, then the theorem may have something to say about their credences and utilities— but