Belief First Franz Huber Department of Philosophy University of Toronto franz.huber@utoronto.ca penultimate version: please cite the paper in The Reasoner I want to defend the thesis that, to the extent that epistemology is a normative discipline, the principle that Ought Implies Can implies that epistemology studies what ideal agents should believe, and how ideal agents should revise their beliefs when they receive new information. To the extent that epistemology is a normative discipline, the principle that Ought Implies Can implies that epistemology does not study what ideal agents should know. The agents I am considering are ideal in the sense that they do not suffer from any computational or other physical limitations and always believe all logical and conceptual truths. The ideal agents also get to voluntarily decide what they believe, and they never forget any of their beliefs. For such ideal agents the principle that Ought Implies Can imposes no constraint on what they should or ought to believe. Indeed, I am inclined to define an agent to be ideal just in case she can carry out any action that is physically possible. In other words, an agent is ideal just in case any action that is physically possible is an action that is possible for her. Such ideal agents ought to do exactly that which they ought to do if they could, where the 'can' in 'could' expresses possibility for the agent, not metaphysical possibility. The restriction to actions that are physically possible is important. My reason for choosing physical possibility rather than, say, metaphysical possibility, is the following. What is possible for an agent is subject to change due to technological and other developments. I take physical possibility to be the "least upper bound", the narrowest modal boundary, for these developments. Physically possible actions that are presently impossible for real agents such as people or computer programs may become possible for those agents at some point in the future. Physically impossible actions may never become possible for those agents. 1 My thesis is that, to the extent that epistemology is a normative discipline, the principle that Ought Implies Can implies that epistemology studies what ideal agents should do qua believers. What ideal agents should do qua believers is to hold certain beliefs, and to refrain from holding other beliefs, and to revise their beliefs in certain ways. (Or perhaps they should hold certain beliefs to certain degrees, and revise their degrees of belief in certain ways. The distinction, and relation, between belief and degree of belief does not matter for present purposes.) What ideal agents should do qua believers depends on their cognitive goals, which may or may not be transparent to them. Cognitive goals may figure as a condition in the ideal agent's conditional obligations to believe, as in the conditional obligation that Sophia should believe that Vienna is the capital of Austria given that she has the cognitive goal of holding a belief that is true and sufficiently informative to answer the question whether Vienna is the capital of Austria. To the extent that epistemology is a normative discipline, the principle that Ought Implies Can implies that epistemology does not study what ideal agents should do qua knowers, unless that is studying what ideal agents should do qua believers (the sense in which an expert ought to have known better, or a child should not have known, are cases where what may seem to be obligations to know really are obligations to do something else: the expert should have gathered more information, and the child should not have had access to certain information). The reason is that knowledge, in contrast to belief (and degree of belief), is not an internal affair (Williamson 2000). Beliefs may also contain an external element in that certain beliefs may be caused by experience. However, how to revise one's other beliefs once those experientially caused beliefs are held is a purely internal affair. We can only require agents to do things that are within their reach, or else we violate the principle that Ought Implies Can. Internal affairs such as beliefs are within the ideal agents' reach, even if the ideal agents' cognitive goals are not transparent to them. Noninternal affairs such as knowledge are not. For instance, we can require Sophia to look if it is raining, and to listen if the TV is on, and to taste whether the pasta is ready. We can also require her to form a belief about whether Vienna is the capital of Austria. However, we cannot require her to see that it is raining, or to hear that the TV is on, or to taste that the pasta is ready. Nor can we require her to know that Vienna is the capital of Austria. Indeed, we cannot even require her to "truly-believe" that Vienna is the capital of Austria. Here to require her to truly-believe so is to require her to believe so, which we can, and for it to be so, or for her to bring it about that it is so, which we cannot. 2 Like their cognitive goals their knowledge may figure as a condition in the ideal agents' conditional obligations to believe, as in the conditional obligations that Sophia should believe that Athens is the capital of Greece given she knows that it is, and that Sophia should not believe that London is the capital of England given that she does not know it is. However, knowledge may not figure in the consequent of a conditional obligation, or in an unconditional obligation: we cannot require Sophia to know that Athens is the capital of Greece, unconditionally or conditional on the assumption that she believes that it is; nor can we require Sophia to not know that London is the capital of England, unconditionally or conditional on the assumption that she does not believe it is. We cannot require Sophia do so, because it is not within Sophia's reach to bring about the external facts that have to obtain in order for her to know, and in order for her to not know. References Williamson, Timothy (2000), Knowledge and Its Limits. Oxford: Oxford University Press.