Have you ever believed dreams can predict the future? Let’s take the example given to us during lecture, Petra dreams Sam’s house catches on fire, the next morning Sam’s house does catch on fire. Did Petra really predict the future? Descarte would argue not. The reason for this being, there is no way we can receive any new knowledge through our dreams. According to Descarte, there are only two ways we can receive or learn any new information, through our senses and intellect. He would argue that everything we see in dreams is simply us processing all the information we gathered throughout the day. Anything we see in our dreams are a result of what we already know. Petra dreaming of Sam’s house catching on fire and it actually catching on fire is only a mere coincidence. What isn’t a coincidence is Petra’s dream. All the concepts she dreamt of are things she already knew to exist, things she had already learned. The fire, Sam’s house, Sam, all of those are concepts she was able to learn through her senses.
Intellect is the knowledge learned from subjects like the sciences and math. Subjects where facts can be proven. In Petra’s dream she dreams of the house catching on fire, well, how did it catch on fire? Because of intellect she is able to guess or assume how the fire might have started. We can’t really think of anything far from our reality. If we try to imagine a mermaid, like Descarte says, we will use our knowledge of women and animals to form this non-existent creature even if we have never seen it ourselves.
Another piece to Descarte’s argument and probably his main goal is creating skepticism or doubt. We receive almost all of our knowledge from our senses. Knowledge that allows us to determine reality from dreaming or that dream state. But, are we really able to trust our senses? Descarte could bring in visual illusions like the example of the straight stick half-immersed in water. The stick will look distorted to us, different from what it actually is, and we will believe it looks like that.
Point is, our senses can be fooled. Once again, those senses are what helps us determine if we are dreaming or awake, if they are fooled we can be fooled into believing we are awake when we are dreaming or dreaming when we are awake. Our intellect can also be fooled. What if everything we have learned about science and math, or just anything in general, is wrong? What if we have been deceived by some superior force, or evil demon as Descarte calls it, and have had the wrong information implanted into our brains? These seem to be very valid arguments because it seems difficult to argue against. It just makes sense.
But it is possible to offer an objection or counter-argument to this argument. In very simple words, you can not be deceived by your senses, intellect or any evil demon if you are aware there is an attempt to fool you, you can see past that decievement. And to answer the question, How do I know I am not dreaming right now? , the answer is also simple. There are ways to determine or distinguish reality from your dream state, reality has consistency whereas dreams may not. In your dreams you may be swimming in the river one moment and the next be climbing a snowy mountain or flying among the birds. In reality that can’t happen, there is consistency and time in the real life. And some things just can’t happen in real life like you fighting a dinosaur, something that is possible in a dream
In conclusion, Descarte says the methods through which we learn things are our senses and intellect. What we learn from these are then processed into dreams, we can not learn anything new from dreams. But what can happen is we can be deceived by our very own senses and intellect, thus proving that we can potentially be living in a dream without realizing.