A Simple Theory of Introspection

This week, I’m blogging about my new book, The Epistemic Role of Consciousness (Oxford University Press, September 2019). Today, I’ll discuss the epistemic role of consciousness in introspection.

What is introspection? Literally, ‘introspection’ means ‘looking within’. But the term is often used as a placeholder for the distinctively first-personal way in which we know our own minds. The task for a theory of introspection is to explain what is distinctive about the way in which we know our own minds. We cannot prejudge the issue by assuming that introspection is a form of inner perception.

In Chapter 5: Introspection, I argue for what I call the simple theory of introspection. How do you know that you feel warm right now? On the simple theory, you don’t need any inner perception of the fact that you feel warm. Rather, the fact that you feel warm itself gives you a reason to believe that you feel warm. Indeed, it gives you a conclusive reason to believe that you feel warm, since it entails that you feel warm. Hence, the fact that you feel warm right now is “luminous” in the sense that it puts you in a position to know with certainty that you feel warm. In order to know by introspection that you feel warm, you just need to believe that you feel warm in a way that is properly based on this reason. No inner perception is required. Hence, the simple theory offers an alternative to perceptual theories of introspection.

Eric Schwitzgebel argues in Perplexities of Consciousness (MIT, 2011) that introspection is unreliable. In many cases, he argues, it is powerless to resolve uncertainty and error about our current conscious experience. Doesn’t this show that the simple theory is too naïve? I don’t think so. The simple theory says that we’re always in an epistemic position to know about our own mental states, but it doesn’t follow that we’re always capable of exploiting our epistemic position. Some cases are easy for us, but others are much harder.  Perhaps there are more hard cases than we realize, but this doesn’t impugn our knowledge in easy cases.

My argument for the simple theory doesn’t rely on psychological evidence about the reliability of our introspective processes. Rather, it relies on epistemological considerations about the irrationality of epistemic akrasia – that is, the phenomenon of holding beliefs that conflict with your higher-order beliefs about which beliefs you should hold. Epistemic akrasia commits you to believing abominable conjunctions, such as the following:

  • p and I don’t have justification to believe that p; or
  • p and it’s an open question whether I have justification to believe that p.

Epistemic akrasia seems like a paradigm of irrationality. If the simple theory is false, however, then it is hard to avoid the implausible result that epistemic akrasia is sometimes perfectly rational.

Suppose you’re in some mental state M that justifies believing that p. And suppose you know that you have justification to believe that p just in case you’re in M. If the simple theory is false, then there is no guarantee that you’re in a position to know that you’re in M. Indeed, you might have justification to disbelieve or to withhold belief that you’re in M. If so, then you have justification to be epistemically akratic – that is, to believe that p, while also disbelieving or withholding belief that you have justification to believe p. But you can never have justification to be epistemically akratic. So, you’re always in a position to know your mental states insofar as they determine what you have justification to believe. The simple theory of introspection explains how this is possible.

The simple theory explains an epistemic asymmetry between introspection and perception. Epistemic rationality doesn’t require knowledge of the external world. An evil demon can deceive us about the external world without thereby impugning our rationality. This is because our beliefs about the external world are ultimately justified by perceptual experiences that can misrepresent the external world. In contrast, epistemic rationality requires introspective knowledge of the mental states that determine what it’s rational for us to believe. An evil demon cannot deceive us about our own mental states without thereby making us irrational. This is because our beliefs about our own mental states are not justified by inner perceptions that can misrepresent our mental states. Rather, our beliefs about our own mental states are justified by the facts about our mental states themselves.

The argument for the simple theory bears on a question about its scope. Which mental states can be known through introspection? Cartesian orthodoxy says that all mental states fall within the scope of introspection, but this is hard to reconcile with the role of subdoxastic mental representations in the science of the mind. The argument from epistemic akrasia suggests that the scope of introspection is limited to mental states that provide epistemic justification for belief. What you have epistemic justification to believe depends not just on your experiences, but also on what you believe. What do these mental states have in common? Perceptual experiences are individuated by their phenomenal character, whereas beliefs are individuated by their phenomenal dispositions. I therefore propose that all mental states that fall within the scope of introspection are individuated by their phenomenal character or by their phenomenal dispositions. On this view, phenomenal consciousness plays an important epistemic role in limiting the scope of introspection.

Where does this leave the zombies among us? Zombies can have mental representations, but they cannot know about their own mental representations on the basis of introspection. The scope of introspection is limited to mental states that are individuated by their phenomenal character or their phenomenal dispositions. Moreover, this explains why mental representations in a zombie play no epistemic role in justifying belief or providing knowledge of the external world. A mental state plays an epistemic role in the justification of belief only if you’re in a position to know by introspection that you’re in that mental state. I’ll elaborate this in my final post tomorrow when I outline my overall theory of epistemic justification.