Majors and Sawyer (2005) have defended a version of reliabilism, home world reliabilism, which says that what is necessary for justified belief is not reliability in normal worlds or reliability in the scenario in which a belief is actually formed, but instead says this:
Rhw: S’s belief that p is justified only if the processes that produced S’s beliefs are reliable in S’s home world understood as that set of environments relative to which the natures of her intentional contents are individuated (2005: 272).
To understand the view, it is important to understand something about the individuation of intentional contents. Thanks in large part to the work of Putnam (1975) and Burge (1979) it is now widely believed that features of the external environment are among the conditions that go towards determining the contents of our intentional states. Burge (1979) defended the view that it is possible for two individuals that are microphysical duplicates to have different beliefs if they were raised in different environments and the further view that the contents of their perceptual states could also differ in light of differences in their environments (1986). If our first individual had been raised in a linguistic community like ours where ‘gold’ was used to refer to a metallic element atoms of which had 79 protons in its nucleus and our second individual was raised in a linguistic community similar to ours that used ‘gold’ to refer to a superficially similar metal atoms of which did not have 79 protons in its nucleus, what these two speakers would assert if they said ‘That is gold’ would differ. (For example, what the first speaker says might be false if said while pointing at a hunk of fool’s gold even if what the second speaker says could be true if said while pointing at the same hunk.) Suppose these speakers then added, ‘Well, that is what I believe, at any rate’. Just as ‘That is gold’ would express different propositions, ‘I believe that that is gold’ would express different propositions. Unless we are prepared to say that one of these speakers cannot correctly self-ascribe beliefs, we have to say that their assertions and beliefs differ in content. The conditions that determine what these individuals believe include their ‘narrow’ conditions (i.e., the conditions held constant when we say that these two individuals are microphysical duplicates) and the conditions found in their environment (i.e., the conditions that determine whether they have been interacting with gold or some superficially similar metal that is not gold).
To see why this matters, note that in setting up the new evil demon thought experiment, we were asked to imagine that there was an individual that is mentally just like us (i.e., an epistemic counterpart) that was situated in an environment that is radically different from our own insofar as this subject was systematically deceived and cut off from causally interacting with her environment in the ways that we do. Anti-individualists might say that this is latent nonsense. It is impossible for a subject to satisfy the first condition and be mentally just like us whilst being situated in a radically different environment because a condition necessary on being mentally just like us is that the subject causally interacts with the kinds of things that we do. The home world reliabilist can say that the new evil demon thought experiment does not cause trouble for reliabilist accounts of justification because when we describe a systematically deceived subject, we are not describing a genuine possibility in which an epistemic counterpart of ours has beliefs produced by wholly unreliable processes. Thus, the home world reliabilist can say that if a subject is an epistemic counterpart of ours, that subject’s beliefs are justified and to the extent that this subject’s mental life is like ours, we have to assume that this subject is not prevented from causally interacting with her environment in the way that the systematically deceived subjects would have to be.
As Comesana (2002: 264) notes, however, it isn’t clear that an appeal to anti-individualism alone can take care of the problem because the problem can reemerge in the form of ‘switching’ cases. Let us suppose that anti-individualism is true and that it is impossible for a subject that is tormented by a Cartesian demon from birth to be an epistemic counterpart of ours. By depriving this subject of the opportunity to causally interact with an environment like ours, the demon prevents this individual from acquiring the kinds of intentional thought contents that we have. What if a subject were allowed to acquire the kinds of thought contents we have by interacting with her environment for a period of thirty years, but the day after the subject’s thirtieth birthday the demon decides to cause her to hallucinate and deceive her about her surroundings? Intuitively, it seems that this newly deceived subject is no less justified in forming her beliefs, but her beliefs will now be wrong as a rule. The home world reliabilist might say that their view delivers this verdict because if the subject had been forming beliefs in the kind of epistemically hospitable environment in which she initially had been forming her beliefs, her beliefs would have largely turned out to be correct. (This seems to require the home world reliabilist to individuate environments in such a way that with the demon’s decision to start deceiving our hapless subject the subject is thereby ‘moved’ into an environment that is not part of the ‘home world’.) I suppose that those sympathetic to Goldman’s (1979) original formulation of reliabilism would be bothered by the implication that so far as the facts that matter to justification are concerned, nothing of significance happened when the demon decided to deceive the subject. It is also odd that on the home world reliabilist view, if the subject thought to herself just after the switch that the beliefs formed after her thirtieth birthday were justified, that belief would be true, but if the subject inferred that those very same beliefs are produced by reliable processes, that belief would be false.
It is hard to know if these are serious problems for the view, but it is worth noting that if the home world reliabilist response is complete, it has to say something about the epistemic status of a demonically tormented subject’s beliefs. Even if no subject tormented from birth by a demon has thoughts or perceptual experiences with the contents that ours have, unless the home world reliabilist is going to say that such subjects have no beliefs at all, we can ask whether such a subject is justified in believing whatever they happen to believe. We know that the home world reliabilist will have to say that if these subjects have justified beliefs, there must be some matters about which their beliefs are reliably correct. It is hard to imagine what these subjects might have reliably correct beliefs about. Note also that the view’s verdicts might not be quite in line with the intuitions to which the critics of reliabilism appeal. Suppose that philosophers ‘discovered’ that some sort of error theory is true. Although the folk might believe things are colored, noisy, good, or what have you, philosophers learn that the world contains no secondary qualities or moral properties. Are we to say that in light of this hard earned philosophical discovery, the ordinary judgments that ordinary folk make about colors or moral properties can never be justified? It seems that the home world reliabilist would have to say that if we were to discover that a subject’s beliefs are not reliably correct by taking account of facts that ordinary folk are non-culpably ignorant of, we would have to pronounce their beliefs as unjustified. It is not clear that this is consistent with the basic intuition that underwrites the new evil demon argument.