The epistemic role of consciousness

The Epistemic Role of Consciousness (Smithies 2019) develops a theory of epistemic justification that gives a fundamental epistemic role to phenomenal consciousness. The book works from the bottom up to build this epistemological theory from foundational assumptions in the philosophy of mind. This précis reverses the order of presentation: it works from the top down to put the epistemological motivations for the theory in the foreground. The book aims to advance the debate between internalism and externalism in epistemology. I generally avoid this terminology, since there are too many ways of drawing the divide, but mine is an internalist theory of epistemic justification in every sense of the term. I argue for phenomenal accessibilism: a version of evidentialism that combines a phenomenal conception of evidence with a higher-order accessibility constraint on the evidential support relation. Here I present the theory as a 12-step program for epistemological addicts. Step 1 is evidentialism: the thesis that you have epistemic justification to believe whatever your total evidence supports (6.1). This is an extremely flexible framework for building a theory of epistemic justification, since it leaves open the nature of evidence and the evidential support. It is not indispensable to the theory, but it provides the most powerful framework for developing it. Step 2 is probabilism: the thesis that the evidential support relation is a kind of probability (7.2.1). It is not just a mathematical convenience to model degrees of evidential support in a way that respects formal principles of logic and probability theory. It reflects an epistemological insight that your total evidence supports hypotheses it entails or makes probable. Probabilism raises familiar concerns about epistemic idealization, but there are resources for addressing them (Smithies 2015). This probabilistic version of evidentialism is common ground between many on all sides of the internalism/externalism debate. Step 3 is a theory of higher-order probabilities (7.1). What are the evidential probabilities of evidential probabilities themselves? This is not guaranteed by the axioms of the probability calculus alone, but I argue on epistemological grounds for an accessibility constraint on higher-order probabilities: necessarily, if it's evidentially probable that p to degree n, then it's evidentially certain that it's evidentially probable that p to degree n. This underpins the JJ Principle: necessarily, you have justification to believe that p if and only if you have justification to believe that you have justification to believe that p. p and I don't have justification to believe that p p and it's an open question whether I have justification to believe that p. A second argument is that justification for belief is constrained by the aim of knowledge: you have justification to believe only what you have justification to believe you're in a position to know. A third argument is that justification is stable under justified reflection: you cannot have justification to believe something that you have justification to abandon upon justified reflection (8.1-8.2, 9.5). Step 5 is to defend accessibilism against objections (5.2, 8.4-8.6, 10.1-10.4, 11.2-11.5). Accessibilism requires that evidence and evidential support relations are self-evident in the sense that they always make themselves evidentially certain (7.2). Defending accessibilism requires answering the objection that you can have misleading higher-order evidence about what your evidence supports and what your evidence is. I respond by arguing that we can defend accessibilism about higher-order probabilities by using the very same resources we need to defend probabilism. The key point is that the evidential support relation is not constrained by the limitations of your doxastic capacity to respond to your evidence. Step 6 is to motivate this idealized conception of the evidential support relation (10.6, 11.6). Why should we care about an epistemic ideal of respecting the evidence that extends so far beyond our limited doxastic capacities? I argue that this normative ideal is implicit in our ordinary understanding of good reasoning. Enkratic agents who violate logical omniscience are thereby committed to fallacious reasoning. Similarly, enkratic agents who violate evidential omniscience are thereby committed to disrespecting their own evidence. Since ideal rationality requires respecting logic and evidence, while also requiring enkrasia, it thereby requires omniscience about logic and evidence. Step 7 is to motivate a constraint on evidence (7.2.2). If accessibilism is true, then your evidence must be self-evident in the sense that it always evidentially certain which facts are included in your evidence. What must your evidence be like in order to make itself evident in this way? If your evidence consists of contingent facts, then it's hard to see how your evidence can be self-evident, since contingent facts cannot always make themselves evidentially certain. Or can they? Step 8 makes an exception for introspection (5.1). A simple theory of introspection says that some facts about your mental states are self-evident in the sense that the fact that you're in some mental state M makes it evidentially certain that you're in M. Once again, the argument appeals to epistemic akrasia (5.3). If M makes it probable that p, but it's uncertain whether you're in M, then you might have justification for believing that p while disbelieving or doubting that you have justification for believing that p. You cannot have justification for epistemic akrasia. So, if M makes it probable that p, then it cannot be uncertain whether you're in M. Step 9 is to answer a question about the scope of introspection (5.4-5.5). Which facts about your mental states are self-evident? There is no good reason to suppose that all mental states are self-evident, since the argument for the simple theory applies only to mental states that provide evidence. Indeed, the universal claim is manifestly false, since subdoxastic mental representations don't make themselves evident. I argue that your current mental states are self-evident just when they are individuated either by their phenomenal character or by their phenomenal dispositions. These phenomenally individuated mental states are good candidates for self-evidence. Step 10 gives a top-down argument for the phenomenal conception of evidence, which says that your current evidence is exhausted by the phenomenally individuated facts about your current mental states (6.4). The phenomenal conception of evidence is motivated by an accessibility constraint, which says your evidence is always self-evident, together with the claim that only phenomenally individuated facts about your current mental states are self-evident (7.2). Step 11 is to give a bottom-up argument for this phenomenal conception of evidence by appealing to intuitive counterexamples to reliabilism, including clairvoyance and the new evil demon (3.1-3.4, 6.3). I try to improve these standard arguments and respond to objections, but I also give them a distinctive spin by exploring parallels with blindsight to motivate the epistemic significance of phenomenal consciousness. Step 12 is to show how these intuitions about cases can be explained and vindicated by locating them within a more general theory of epistemic justification (7.3-7.4). They are not just gut reactions. A purely intuition-driven approach to epistemology is dialectically ineffective and theoretically unsatisfying. Phenomenal accessibilism is explicitly designed to explain why these intuitions are well motivated and to provide them with theoretical support. Internalist theories of epistemic justification tend to be strong on intuitive conviction but weak on theoretical principle. One exception is phenomenal conservatism, which promises to explain all epistemic justification in terms of a single epistemic principle that you should always believe what seems on balance to be true (12.1-12.2). But while this theory gives a plausible epistemology of perception, it severely distorts the epistemology of memory, introspection, inference, and higher-order evidence (12.3-12.4). My hope is that phenomenal accessibilism will be taken seriously as an alternative to phenomenal conservatism by anyone who is interested in assessing the prospects for an internalist theory of epistemic justification that is not only intuitively compelling, but also theoretically principled

Consciousness · Epistemology · Epistemology, Ethics, and Metaphysics · Philosophy · Philosophy and History of Science · Philosophy and Theoretical Science · Psychology