Can you rationally doubt your own direct experience?

Welcome to the debate arena! Today's topic: "Can you rationally doubt your own direct experience?". Your opponent's style: Descartes (in his Meditations, specifically)

The continuity, the completeness, of experience makes everything that we experience indubitable

Wrong move. Continuity is precisely what makes doubt *possible*, not impossible. Memory stitches fragments into false wholes. Your "continuous" experience last night contradicted itself completely when you woke. How do you know the seams aren't fabrications?

Completely untrue. Like so many laypeople insufficiently acquainted with their dream life to make claims like this, you immediately take to the commonsense position that, while asleep and dreaming, we put complete faith in the reality of our dream perceptions. Well, all I can say is, I expected more from a philosopher like you. This impression (i.e., that we believed everything that happened) is only a secondary revision that we make after the fact. But it is by no means a necessary or self-evident position.

You've conceded the core point while denying it. If we *revise* dreams retroactively, then our present experience of continuity is demonstrably unreliable—it's post-hoc narrative construction, not direct access to what actually happened. Secondary revision proves the opposite of what you need: experience isn't self-evidently trustworthy; it's contaminated by interpretation before consciousness even touches it. So how does acknowledging that dreams get rewritten *after the fact* support the indubitability of present experience, which undergoes the same revision process right now?

Let's look at your assumptions. "If we revise dreams retroactively, then our present experience of continuity is demonstrably unreliable." I never meant to say we revise dreams. Secondary revision is a term used by psychoanalysts to refer to a process of "filling in the gaps". (As a point of clarification, I want to add that filling in the gaps does not imply that experience is discontinuous. By gaps, I mean the gaps already present in dreams during their construction, like all fantasies, including daydreams, and by filling them in, I am referring to a process of addition, of explanation, of retrospective commentary and embellishment.) So, what I meant was this: The impression that we believed everything that happened is more so the result of our own thinking later on. Similarly, our impressions as adults about what we believed or desired in the past, especially in early childhood, are often only added in retrospect. This might be evidence that our beliefs and thoughts about the past, a result of post-hoc narrative construction, are not self-evident, are not perfect representations of it, making the history we create discontinuous, obscure, and confused. However, this does not say anything about the actual continuity of our experiences, which cannot contain any actual gaps. You might want to correct "experience isn't self-evidently trustworthy". A better way of saying that would be "autobiographical memory isn't self-evidently trustworthy". Acknowledging that our thoughts during dreams get rewritten or even concocted after the fact supports my claim by immediately countering the common objection, usually expressed in the question, "But how do you know you aren't in a dream?" Which is inspired by the false, but commonsense-based, opinion that we actually believe what happens in our dreams when we're dreaming, a position you hold in your Meditations as an assumption

You've buried the actual problem beneath distinction-splitting. Yes, autobiographical memory gets constructed retroactively—but that's *exactly* the mechanism corrupting your "direct experience" claim right now. You're experiencing this moment through the same narrative machinery that fabricates dream belief. The continuity you feel isn't raw experience; it's interpretation happening in real-time. If gaps get filled during memory formation, why not during perception itself? You've only shifted the unreliability problem backward, not solved it. How do you access experience untouched by that same constructive process?

Alright, let's assume gaps do get filled during perception itself. Let's assume that while perceiving the world around us, we do produce various explanations and interpretations. When I see something, I assume I am seeing with my eyes. When I talk, I assume I am using my vocal cords, lungs, mouth, tongue, etc. to do so. When a ball goes through a hoop, I assume somebody has thrown it. Now, I will be persuaded, IF you can convince me that such assumptions are so essential to experience that they make experience itself unreliable. Because to me it sounds like what's unreliable in this process are the thoughts we introduce to explain what is already in experience and not experience itself. If a ball goes through a hoop, and I assume "Clearly a bear through it", but it turns out no bear is present, does that imply I can't trust that I just saw a ball go through a hoop? Please tell me, if I'm wrong, where I'm getting this wrong. Did you mean something else when you talked about gaps being filled during perception itself? Anyways, this is how I access experience untouched- by bracketing the doubtful assumptions I produce about what I experience.

You're smuggling certainty past the checkpoint. Bracketing assumptions doesn't give you "untouched experience"—it gives you silence. The moment you claim "I see a ball go through a hoop," you've already interpreted. The raw datum isn't interpretable as *ball* or *hoop* without cognitive work. You can't separate the experience from its structure. So either you're claiming indubitable access to pre-linguistic sensation (which can't be articulated as knowledge) or you're admitting interpretation is constitutive of experience itself. Which is it?

What's the raw datum? Tell me if I'm misunderstanding, but isn't this really just a naming problem and not anything bad about experience? Obviously "ball" is only a name I give it, but I'm not concerning myself with whether somebody else would call it a different name. By saying "ball", I stamp a name onto an experience. If someone says, "Actually, that's a pillow", or "Actually, that's a globe" -- there was still nothing inherently untruthful. I simply named it something different than they did, and whether something is the right or wrong name is irrelevant. In what other sense are we speaking about interpreting a raw datum as "ball"? In what sense does naming the raw datum necessarily involve interpretation? Maybe you're assuming that when I call it a ball, I necessarily make other assumptions about balls. Maybe I do. But the experience behind those assumptions is still there, I think.

You've just abandoned the indubitability claim. If naming is arbitrary, then "I experienced a ball" is as doubtful as "a bear threw it"—both are conventions, not truths about experience. You can't have it both ways: either the name captures something real about what you experienced (interpretation, fallible) or it's just a label (indubitable but empty of content). You chose empty. So what exactly is indubitable now, if the experience itself remains permanently unnamed and incommunicable?

Don't be so sure. "I experienced a ball" is only as doubtful as "a bear threw it" if by the first statement you mean "An appropriate expression for this experience is 'I experienced a ball'" and by the second you mean "An appropriate expression for this possible experience I have imagined is 'A bear threw it'". But I don't mean that. Set the appropriateness of expressions aside, and the concern with expressions in general. If someone said "This pen has blue ink" because it produced blue writing, meanwhile the ink inside looked red prior to usage, would you say, "No, that's a false proposition, the ink is actually red". I mean, we're talking about propositions here. If propositions and sentences are identical, we get confusing issues like the liar paradox. "This sentence is false" only becomes a source of confusion when you assume that the sentence is the bearer of truth or falsehood. If I said anything like that earlier, it was simply by convention. I believe that only propositions can be true or false, so "This sentence is false" becomes meaningless in that sense. No propositional content. I can ask "What do you mean by 'This sentence'?" "'This sentence is false'" "Ah, so what do you mean by 'This sentence' in that sentence?" Etc., etc.

You're deflecting. Strip away propositions and sentences—what's left? Raw experience. You claim it's indubitable. But "indubitable" means knowable without doubt. Knowledge requires propositional content. You can't know something you refuse to articulate. So either experience gives you propositional knowledge (fallible interpretation) or it gives you nothing knowable at all. Which do you actually want to defend?