1. An epistemic puzzle

Susanna Siegel, The Rationality of Perception (Oxford, 2017)

On a traditional conception of the human mind, reasoning can be rational or irrational, but perception cannot. Perception is simply a source of new information, and cannot be assessed for rationality. I argue that this conception is wrong. Drawing on examples involving racism, emotion, self-defense law, and scientific theories, The Rationality of Perception makes the case that perception itself can be rational or irrational.

The Rationality of Perception argues that reasoning and perception can be deeply intertwined. When unjustified beliefs, fears, desires, or prejudices influence what we perceive, we face a philosophical problem: is it reasonable to strengthen what one believes, fears, or suspects, on the basis of an experience that was generated, unbeknownst to the perceiver, by those very same beliefs, fears, or suspicions? I argue that it is not reasonable-even though it may seem that way to the perceiver. In these cases, a perceptual experience may itself be irrational, because it is brought about by irrational influences.

Here’s a simple example. Jill fears (without good reason) that Jack is angry with her. As a result of her fear, Jack’s face looks angry to her when she sees it. If you saw Jack, you’d see his neutral expression for what it is. There’s no need for Jill to jump to conclusions from what she sees. Her fear’s influence on perceptual experience makes it simpler for her: she can just believe her eyes.

Let’s suppose that Jill has no idea that her fear has influenced her perceptual experience. To her, she’s simply seeing Jack, and following common sense in believing her eyes – since as far as she can tell, she has no reason not to believe her eyes.

Is it reasonable for Jill to believe her eyes, when her visual experience is a projection from an unreasonable fear or presumption? It might seem that the answer is Yes. What else is Jill supposed to believe, given that she has no idea her fear has been projected onto her experience? In countless other situations, it’s reasonable to believe what you see. If you want to know whether there’s mustard in the fridge, for instance, then if you see some mustard (and have a visual experience of a sort that typically goes with seeing mustard), it’s clearly reasonable to believe that the fridge contains mustard.

On the other hand, there’s something fishy about Jill’s strengthening her fear on the basis of her perception, given the role of the fear in generating the key aspects of her visual experience – the aspects that make the fear seem reasonable. If Jill’s fear starts out unreasonable, how could it become reasonable, just by shaping the crucial contents of a visual experience?

Here we have one of the classic forms of a philosophical problem. There’s a seemingly straightforward Yes-or-No question, where both answers seem plausible. My next post will outline the answer I believe is correct.


  1. Great puzzle, beautifully stated! I’m inclined to distinguish the extent to which a psychological state is rationally warrantED from the extent to which it is rationally warrantING, and to say that the perceptual states that are influenced in the untoward way described here are less rationally warranting than most perceptual states are. But they are no more or less rationally warranted — because, as tradition would have it, they are not rationally warranted at all. That’s what I’m inclined to say, but I’m always eager to hear what Prof. Siegel has to say!

    • Susanna Siegel

      Thanks, Ram! I agree that the tradition that excludes perceptual experience from the domain of the warranted has powerful reasons behind it. Perhaps one of the strongest ideas in tradition’s favor is that perceptual experience is a basic level of evidence that doesn’t depend on any other epistemically relevant factors (putting aside defeaters or countervailing considerations).

      As I see it, cases like Jack and Jill call that idea into question. Jill’s fear can in principle influence her experience in a way that makes its epistemic power depend on other factors (even when it isn’t defeated, in the traditional sense). So the idea that experiences are epistemically basic is called into question, even if you stop short of bucking the tradition in the analysis of the cases, and hold (as you suggest) that Jill’s experience is merely less warranting than it could be, if it weren’t influenced by her fear. And at that point, the traditional view that experience can’t be warranted or unwarranted seems less powerfully motivated.

  2. V. P. P.

    The claim that perceptual experiences can be rational or irrational is very interesting. I’m sure you talk a lot about this in the book, but it would be very useful here with a short statement of what you take a perceptual experience to be. Some would perhaps say that perceptual experiences are beliefs, and so the conclusion wouldn’t be radical at all. Some would perhaps say that they involve several distinct elements, like sensations, seemings, and perhaps some intermediate map-like state. On such a view, the conclusion might not be that radical, since one might claim that it is one of the elements, e.g. the seeming, that is irrational and which renders the overall experience incapable of providing justification. Since seemings seem much closer to belief than say a sensory state, the idea that they can be rational or irrational might not be that surprising. It’s easy to see how a belief that someone is angry can make it seem to you as if they are angry, and it is easy to see why we wouldn’t want to say that, in the absence of further corroborating evidence, the seeming can justify the belief that they are angry – that would seem to force us to claim that any belief can justify itself by generating a seeming. But it is harder to see how a belief that someone is angry can produce a sensation or some lower-level state as of them being angry. So it would be very helpful with a brief statement of your view as to the nature of perceptual experience.

  3. V. P. P.

    I guess the tradition has a more restricted notion of perceptual experience in mind when it claims that they do not depend on further evidence. If one takes it to include a seeming, for instance, we’re on the way to claiming that they involve assertive propositional content. And I guess lots of people already think that things with assertive propositional content must be assessable for justification (even if they’re not beliefs). So that’s another reason why it would be nice with a statement of your notion.

    • Susanna Siegel

      Hi V.P.P. I think my reply (below) to your first comment addresses part of your second comment, in addressing the two-part idea that (i) having ‘assertive propositional content’ is sufficient for being a belief, and (ii) being a belief is sufficient for being epistemically appraisable. I think part (i) is too quick. And if “assertive” in “assertive propositional content” means the same as “having propositional content with the cognitive profile of belief” (or with one of its many cognitive profiles), then the two-part idea is what’s at issue. If “assertive” means something else, then I think more needs to be said about why having ‘assertive propositional content’ is sufficient for being epistemically appraisable.

  4. Susanna Siegel

    Thanks, V.P.P. Perceptual experiences are phenomenally conscious states of the type one is usually in when perceiving. They’re missing from unconscious perception, and can in principle occur in hallucination. So in my usage, “perceptual experience” denotes a phenomenological category, rather than a category marked off by vision science (for the visual case), or by perceptual relations that constitutively involve external-world objects and properties.

    Within this category, as you suggest, some philosophers find it useful to distinguish ‘seemings’ from ‘sensations’. Others try to assimilate experiences to beliefs.

    My approach differs from both of these. The phenomenology of perception is full of differentiation. Part of the phenomenology of perception is the differentiations belong to external-world things, rather than being features of our own minds. I think the best way to analyze this kind of differentiation, and probably the only way, is in terms of properties that are attributed to things (objects, spaces, people, etc).

    On this analysis, perceptual phenomenology involves something like predication. For instance, when you have a visual perceptual experience of a red round thing, you attribute roundness to that thing. And once there’s predication in experience, there are accuracy conditions. Your experience is accurate only if the thing to which you attribute roundness really is round.

    (What I’ve just said is a condensed version of the view defended in chapter 2 my earlier book *The Contents of Visual Experience* (2010).)

    What about the distinction between seeming and sensation? And why doesn’t the framework of accuracy conditions make experience into a kind of belief?

    Let’s take the belief question first. Laurence BonJour, on behalf of Wilfred Sellars, worried in effect that if experiences had accuracy conditions, that would make them into beliefs. (This idea was part of an alleged dilemma. The other horn said that if they lacked accuracy conditions, they couldn’t provide justification). In response, many philosophers argued, and I agree, that a psychological state’s merely having accuracy conditions didn’t suffice to make them into beliefs. After all, we can assess imaginations for accuracy too, once we specify a situation relative to which we’re assessing them. When you imagine whether your piano will fit through the door, you can get into a state that is accurate or inaccurate, relative to certain doors and pianos. More generally, the cognitive profile of beliefs differs from perceptual experiences. For a start, beliefs have an inbuilt inertia that perceptual experiences lack. You don’t have ‘refresh’ your beliefs all the time – they can naturally fade into memory. Beliefs may die from your forgetfulness, but experiences pass all on their own, whether you forget them or not.

    What about the distinction between sensation and seemings? In the framework of accuracy conditions (sometimes called the Content View of perceptual experience), we can draw further distinctions if we want to, such as the distinction between ‘low-level properties’ and ‘high-level properties’. There’s no official list of which properties are ‘low’ and which are ‘high’, but for visual experience the low-level ones are commonly taken to include color, shape, and motion, whereas typical high-level properties include causation, kinds, faces, affordances, social properties of various sorts, and personal identity (such as the property of being Angela Merkel).

    If the distinction between sensation and seemings is merely the distinction between low- and high-level contents, then it’s hard to see why seemings are closer to belief. People have beliefs attributing low-level properties, and there are lots of cases like Jack and Jill where instead of fear, desire, suspicion, knowledge, or prejudice resulting an an experience with high-level content it results in an experience with low-level content. For instance, knowledge that bananas are yellow can make a grey banana looks yellowish.

    Sometimes philosophers who differentiate seemings from sensations have a more radical division in mind, where the seemings have accuracy conditions but the sensations do not. I’m suspicious of this category of sensation, when it’s meant to be a component of every visual experience. (Perhaps blurred vision might involve something like a sensation in this sense, though it’s a vexed phenomenon).

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