 There are different ways of construing the dream argument. A strong reading is that Descartes is trapped in a lifelong dream and none of his experiences have ever been caused by external objects (the Always Dreaming Doubt; see Newman 2019). A weaker reading is that he is just sometimes dreaming but cannot rule out at any given moment that he is dreaming right now (the Now Dreaming Doubt; see Newman 2019). This is still epistemologically worrisome: even though some of his sensory-based beliefs might be true, he cannot determine which these are unless he can rule out that he is dreaming. Doubt is thus cast on all of his beliefs, making sensory-based knowledge slip out of reach.