The Argument from Defeasibility challenges the idea that there are non‐inferentially justified beliefs by challenging the idea that there are indefeasibly justified beliefs. Beliefs that are defeasibly justified are things that you can rationally reject or suspend judgment on as new evidence comes in. In the case of sudoku, there's no process that should lead you to believe that the rational way to solve the puzzle is to change the numbers given at the start of the puzzle. If non‐inferential beliefs are akin to the numbers given at the start of the puzzle, shouldn't we think of these beliefs as rationally unrevisable? If so, since every belief is rationally revisable, shouldn't we think that there aren't any non‐inferential beliefs?
1.80 What can the foundationalists say in response? They have two salient options which track different ways of characterizing the relationship between foundational beliefs and defeasibility:
Option 1: the foundationalist might agree that foundational beliefs have to be indefeasibly justified, and they might defend their view by trying to show that there are such beliefs and that there is a sufficient stock of such beliefs to serve as the foundation for all of our knowledge.
Option 2: the foundationalist might deny a foundational belief has to be indefeasibly justified. As they see it, so long as a belief is supported by something that isn't a belief and the support this belief receives isn't defeated, this could be good enough to justify a belief. Much as a promise, say, can justify an action in the absence of defeating reasons, perhaps an experience – or perhaps a certain causal source – can justify a belief in the absence of defeaters.
1.81 We may call foundationalists who opt for Option 1 classical foundationalists and those who opt for Option 2 modest foundationalists. The classical foundationalist simply embraces the idea that our foundationally justified beliefs have the two features that the given numbers in sudoku have, which is that they are (i) beyond rational revision as well as (ii) the foundation for all justified belief. The modest foundationalist, by contrast, rejects the idea that these two features come together. As they see it, the sudoku analogy is useful, but only within reasonable limits. As they see things, an important difference between, say, our beliefs about the external world and our beliefs about the grid is that the former can be justifiably held on the basis of reasons that provide only defeasible support.
1.82 We'll have more to say about the respective virtues of the classical and modest foundationalism in Chapter 2 (in connection with perception) and in Chapter 3 (in connection with the particular and vexed case of a priori justification). The important point to take from the present discussion is that there are two ways for the foundationalist to respond to the Argument from Defeasibility and thus two ways to flesh out the details of that view.
1.83 Whereas the Argument from Defeasibility invites us to take a side in a disagreement between classical and modest foundationalists without forcing us to abandon foundationalism altogether, a further line of argument poses a serious threat to foundationalism in any form.
1.84 What distinguishes the foundationalists from the critics of foundationalism is a commitment to the possibility of non‐inferentially justified belief. It should be possible, on the foundationalist model, for a belief, p, to be justified in virtue of possessing some feature, F, even if the subject doesn't have any opinions about whether her belief that p even has this feature F.38
1.85 And here, according to BonJour (1978), is the source of the problem. For a belief to be justified, it is supposed to be properly connected to the truth. Presumably, this is what F does. The possession of F ensures that beliefs that are F are properly connected to the truth. Here's the problem. BonJour thinks that it's important to the very idea of a justified belief that such a belief is responsibly held. To be responsibly held, however, he thinks that the believer would have to be cognizant of the fact that her beliefs have this feature F. This, however, creates trouble for the idea that the relevant belief is immediately justified. To be cognizant of the fact that the belief has this feature F, the subject would have to have an opinion – some further belief – about whether her belief had this feature. But this is incompatible with the idea that the relevant belief's justification doesn't derive, in part, from the subject's other beliefs.
1.86 We can state the crux of BonJour's argument as follows:
Doxastic Ascent Objection
P1: if some belief (e.g. B1) is non‐inferentially justified, it must be possible for B1 to be justified simply because it has some feature F (i.e. justified in such a way that B1's justification does not derive from any further beliefs the believer has about B1).
P2: it is not possible for B1 to be justified simply because it has some feature F because justified beliefs are responsibly held and it's not responsible to hold B1 unless you recognize that B1 has F.
C: B1 cannot be non‐inferentially justified. (And what goes for B1 goes for B2, B3, B4, etc.)
1.87 How powerful is this objection? Notice that the objection rests on two crucial assumptions:
Assumption 1: justified beliefs are responsibly held beliefs.
Assumption 2: a belief isn't responsibly held unless we have beliefs about the features of this belief (e.g. beliefs about what's good about this belief).
1.88 Assumption 1 seems harmless enough. One way to show that a belief isn't justified is to show that it isn't responsible to have an opinion about the issue.39 It's Assumption 2 that seems problematic. Why should we think that responsibility requires meta‐beliefs?
1.89 It helps to remember the kinds of things that foundationalists might offer in giving a substantive specification of F. They might say that if you have a spontaneous visual belief about your surroundings or a spontaneous introspective belief about what you're currently thinking about, these beliefs will be justified non‐inferentially. When you think about good candidates for F, you're supposed to think of the things that would be good resources for settling a question. You might think that to believe responsibly is just to use the best resources for settling a question, in which case there'd be nothing more to responsible believing than forming F‐beliefs. To responsibly settle the question as to whether we're low on milk, you check the fridge. To responsibly settle the question as to what sort of mood you're in, you introspect. It doesn't seem to be a failure on your part that would merit the charge of irresponsibility if – after checking the fridge and seeing that it's empty – you don't continue to think about the reliability of vision. Isn't checking the fridge and judging straight off that there's no milk hiding in the empty fridge a perfectly responsible way of settling that question?
1.90 Recall again the argument from cases. The intuitions that underwrote that argument were supposed to show that there were clear cases where a person can come to have knowledge or justified belief “straight off,” without having to do any further reasoning. They simply rely on introspection (i.e. reflecting on your own mental states) or perception, say. Part of what accounts for this intuition seems to be that we see this kind of openness to the deliverances of introspection or perception as the manifestation of epistemic responsibility. If we didn't, we presumably wouldn't find the intuition gripping. What this suggests is that the intuitions that underwrite this argument speak directly against the crucial assumption in BonJour's argument (Assumption 2).
