What is the truth?
What is the truth? Is it the set of beliefs we are endowed with once we are kicked into this world? But that isn't the case, right? How many times did we find that something we used to believe as children turned out to be some kind work of a devil trying to decieve us? For surely now I know that Santa Claus doesn't ride his deer every christmas to get presents for the good boys is nothing but a modern myth. What is the truth then? This is the mission that Descartes was set on in his meditations.
Several years have now passed since I first realized how numerous were the false opinions that in my youth I had taken to be true, and thus how doubtful were all those that I had subsequently built upon them.
Although it's quite self-evident, we must ask ourselves first: why do we seek truth? The answer is really simple. No one wants to build their whole life on lies; no one wants to spend his whole life looking for some kind of magical water that endowes any drinker of it immortality, because that's absurd and a waste of life. So, we seek truth to not waste our life. We seek truth because we are, by nature, creatures that seeks meaning and only in truth, we find true meaning. With that out of the way, Descartes realized that numerous false ideas he once believed to be true turned out to be otherwise. So, how can we be sure of any kind of beliefs we have? How can we construct a system of truth? To be able to do this, one must not be prejudiced or biased in any kind of way, because maybe his bias or prejudice is based on a false idea, and therefore his whole conclusions he draws on different matters would be flawed. Therefore, we must first abolish the set of all beliefs that we have and start anew. That's what Descartes exactly did:
And thus I realized that once in my life I had to raze everything to the ground and begin again from the original foundations, if I wanted to establish anything firm and lasting in the sciences.
To begin his journey, Descartes decided that he would reject any idea that is clearly and vivdly false. Not that only, but he also decided that any idea that is suspect to any kind of doubt is as false as clearly and vivdly false ideas, for he doesn't want to base his system of truth based on something that is vulnerable to doubt. But how can he do so? There are hundreds of thousands, and maybe even millions, of ideas. Attacking each one individually would be a troublesome task that couldn't be completed in any lifetime. Descartes instead decided to attack groups of ideas instead of each idea individually. He will do so by attacking the foundations on which such ideas are built. If they turn out to be false or suspect to doubt, he can reject this group of ideas as a whole:
Nor therefore need I survey each opinion individually, a task that would be endless. Rather, because undermining the foundations will cause whatever has been built upon them to crumble of its own accord, I will attack straightaway those principles which supported everything I once believed.
The Devil's Senses
Have you ever once drove in the middle of the desert on a hot flaming day and saw a lake that was way far from you? But then you drive towards that lake and it only gets farther and farther and you seem to never catch it. You will never get to that lake because it never existed. Your eyes and brain decieved you to perceive a lake because the way light is refracted and reflected in the differnt layers of the atmosphere. What makes you trust something that can deceive you, then?
Surely whatever I had admitted until now as most true I received either from the senses or through the senses. However, I have noticed that the senses are sometimes deceptive; and it is a mark of prudence never to place our complete trust in those who have deceived us even once.
But you are certainly reading this blog post right now, right? you are monitoring the laptop or the phone using your hands, right? you can also see the light filling your room (or maybe even the dark), right? Definitely these are things that you can't doubt. But maybe you are also dreaming? You remember at least one dream where you were also sitting in front of the laptop in a light-filled room. But you couldn't tell at that time whether it was a dream or not. Maybe that's the case? Maybe you are dreaming right now and nothing is real. Descartes takes it even a step farther arguing maybe that you have no hands or there's nothing called "light" or "laptop":
Let us assume then, for the sake of argument, that we are dreaming and that such particulars as these are not true: that we are opening our eyes, moving our head, and extending our hands. Perhaps we do not even have such hands, or any such body at all.
But even if we are dreaming, at least things like the "eye", the "hands", the "head", and the "light" are derived from true things:
Nevertheless, it surely must be admitted that the things seen during slumber are, as it were, like painted images, which could only have been produced in the likeness of true things, and that therefore at least these general things—eyes, head, hands, and the whole body—are not imaginary things, but are true and exist.
Therefore, even the physical things are subject to doubt. Descartes then concluded that all the sciences based on the "physical things", are themselves subject to doubt. But then he realized that arithmetic, geoemtery, algebra and fields that deal with abstract or general concepts with little regard to whether they existed or not, contain the most certain and indubitable facts:
For whether I am awake or asleep, two plus three make five, and a square does not have more than four sides. It does not seem possible that such obvious truths should be subject to the suspicion of being false.
But then he even doubts this kind of assertion. He realizes that since people sometimes even mistaken the ideas they see as most clear and certain, how can he be sure that a triangle has only three sides, or 10+10 = 20?
Accordingly, I will suppose not a supremely good God, the source of truth, but rather an evil genius, supremely powerful and clever, who has directed his entire effort at deceiving me. I will regard the heavens, the air, the earth, colors, shapes, sounds, and all external things as nothing but the bedeviling hoaxes of my dreams, with which he lays snares for 23 my credulity. I will regard myself as not having hands, or eyes, or flesh, or blood, or any senses, but as nevertheless falsely believing that I possess all these things.
By the end of this meditation, Descartes reaches a dead end rather than establishing his so-called system of truth. He's confronted with more challenges and problems than he had when he start this meditation:
In just the same way, I fall back of my own accord into my old opinions, and dread being awakened, lest the toilsome wakefulness which follows upon a peaceful rest must be spent thenceforward not in the light but among the inextricable shadows of the difficulties now brought forward.