I think today's generation is very familiar with this concept of dreaming vs reality because of films like The Matrix, but I looked into it with a little more depth recently because I covered a tidbit of Descartes' Meditations in Intro to Philosophy.
The argument goes that it's impossible to distinguish whether you are asleep or awake.
He's just finished talking about how things can be different than they actually seem to be, such as the sun seems very tiny to us in the sky, but in actuality, it is many many times larger than Earth. This is to establish that you can't always trust your senses to get reliable factual data.
Uh oh, now he's beginning to examine his own existence..."But perhaps, even though the senses do sometimes deceive us when it is a question of very small and distant things, still there are many other matters concerning which one simply cannot doubt, even though they are derived from the very same senses: for example, that I am sitting here next to the fire, wearing my winter dressing gown, that I am holding this sheet of paper in my hands, and the like." - Descartes, Meditation 1, 19
So read over what he curtly says, and think about it. Think to yourself what you think dreaming is, and what you think being awake is. Do you recall ever having a dream that was very close to reality? If you cannot recall, can you possibly believe that a dream can be similar to reality?"This would all be well and good, were I not a man who is accustomed to sleeping at night, and to experiencing in my dreams the very same things. ... How often does my evening slumber persuade me of such ordinary things as these: that I am here, clothed in my dressing gown, seated next to the fireplace--when in fact I am lying undressed in bed! But right now my eyes are certainly wide awake when I gaze upon this sheet of paper. This head which I am shaking is not heavy with sleep. I extend this hand consciously and deliberately, and I feel it. Such things would not be distinct for someone who is asleep. As if I did not recall having been deceived on other occasions even by similar thoughts in my dreams! As I consider these matters more carefully, I see so plainly that there are no definitive signs by which to distinguish being awake from being asleep." - Descartes, Meditation 1, 19
So, do you think you're awake or asleep right now, and why?
As for me, I don't know what to think anymore.
(P.S. No evil genius arguments please, this isn't Pay to Post forums)