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Language and Logic
be one unique antecedent world most resembling the actual world. But can we really be sure of this? Will there always be, for any antecedent A at most one A- world most resembling the actual world? Couldn't there be cases where we have several such ^-worlds, all equally close to the actual world and all closer to the actual world than any other world? In Lewis 1973 the following examples are given to show that such cases really do exist:
If Bizet and Verdi had been compatriots, Bizet (4) would have been Italian.
If Bizet and Verdi had been compatriots, Verdi (5) would have been French.
Because of the uniqueness assumption, Stalnaker's theory does not admit a situation in which both (4) and (5) are false while (6) is true:
If Bizet and Verdi had been compatriots, either (6) Verdi would have been French or Bizet would have been Italian.
According to Lewis one can accept (6) without having to accept (4) or (5), and so he rejects the uniqueness assumption. There are more variants of Stalnaker's theory on the market. They differ from each other mainly in assigning slightly different properties to the underlying comparative similarity relation of worlds, thus giving rise to slightly different conditional logics.
In Tichy 1976 an objection is raised against Stal- naker's theory which applies to other versions of the 'minimal change' paradigm as well. The argument runs as follows: 'Consider a man—call him Jones— who is possessed of the following dispositions as regards wearing his hat. Bad weather invariably induces him to wear a hat. Fine weather on the other hand, affects him neither way: on fine days he puts his hat on or leaves it on the peg, completely at random. Suppose moreover that actually the weather is bad,
soJones iswearinghishat...' What isthe truth value of the following counterfactual?:
If the weather were fine, Jones would be (7) wearing his hat.
Intuitively, this sentence is false—if the weather were fine, Jones might very well not be wearing his hat. But according to the theories mentioned above it is true. After all, it would seem that worlds where Jones keeps his hat on are at least in one respect more like the actual world than worlds were he takes it off.
The advocates of the minimalchange approach are of course not ready to admit this. According to them the example shows at best that not all characteristics of the actual world are relevant in assessing which worlds resemble it more than which other worlds. The obvious next question—which characteristics are relevant and which are not?—is usually delegated to pragmatics.
See also: Conditionals.
Bibliography
Edgington D 1995 On Conditionals. Mind 104: 235-329 Goodman N 1946 The problem of counterfactual
conditionals. Journal of Philosophy 44: 113-28
Harper W L, Stalnaker R, Pearce G (eds.) 1981 IPS Con- ditionals, Belief, Decision, Chance, and Time. Reidel,
Dordrecht
Lewis D 1973 Counterfactuals. Basil Blackwell, Oxford Ramsey F P 1931 General propositions and causality. In:
Ramsey F P Foundations Essays in Philosophy, Logic, Mathematics and Economics. Routledge and Kegan Paul, London
Rescher N 1964 Hypothetical Reasoning. North-Holland, Amsterdam
Stalnaker R 1968 A theory of conditionals. In: Studies in Logical Theory, American Philosophical Quarterly. Mono- graph Series, No. 2. Basil Blackwell, Oxford
Tichy P 1976 A counterexample to the Stalnaker-Lewis analysis of counterfactuals. Philosophical Studies 29:271- 73
'Logic' is not so well-defined a term, nor logic so tidy or static a discipline, as the popular conception of the logician as a paradigmatically convergent thinker minding his ps and qs might lead one to suppose. In the context of this article, 'logic' will be used in quite a narrow sense: to refer only to deductive logic (not
to inductive logic or other considerations of a more methodological stripe) and only to formal logic (not to theories of truth or reference or analyses of the proposition or other considerations of a more philo- sophical stripe). Even within logic thus narrowly con- ceived, however, a profusion of formal deductive
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Deviant Logics S. Haack