How philosopher Rene Descartes Changed the World

What is your reality? Do we and our world around us truly exist or is it all an illusion or a complex dream of the mind or some evil beast playing tricks? This is what philosophers call the ‘cartesian problem’, which stems from the famous French philosopher Rene Descartes. The question, then, becomes: Does the external world truly exist as we experience it? I break down Descartes’ arguments through his method of thinking, which is truly a brilliant method he articulated in the 1600’s. He changed the world with his way of thinking.

Blog entry is a week late this time but I shall put up 2 blog entries in same week to make up for last week (Both on the ideas of Descartes).

rene descartes


Reality is something that  is difficult to wrap our minds around. Philosophers have been debating over this for many millennia. In order to get to the problem of external world, we must start with the existence of the subjects: humans. Descartes asked himself: Do I truly exist? That is where we start.

I already alluded to it to some degree above, but the problem that Descartes faced in the 1600’s was truly interesting. Does nature and the world around us exist just like we experience it with our senses or is there more to it that our senses cannot detect? In fact, do we humans and the world even exist or is it simply part of a complicated dream that we (or this mystical figure we call ‘god’) are conjuring up? If it is the latter then it would mean that we do not physically exist at all and everything we see, touch or feel is truly not there. If it is the former, then we must first prove that we truly exist. The question is how do we prove that we exist?

It was, most definitely, not a new problem. The Greek philosophers faced this long before Descartes, and there is no doubt that the Eastern philosophies in ancient China & ancient India also faced this problem (unfortunately, I do not know much about Eastern philosophy so I cannot say much about it).

The most important byproduct of this entire problem was something called ‘Cartesian method’ that Descartes created to analyze this problem. He knew that in order to study this problem, one must doubt everything to get down to the basics. Things like human thoughts, biases, philosophies, beliefs, etc would all get in the way of solving the problem of reality so Descartes wanted to get all that out of the way. So Descartes must devise a powerful philosophical argument to show that we definitely exist. He sits there thinking and dividing his argument into six pieces — he called the pieces ‘six meditations’. I will explain that further below.

Anything that can be doubted (or questioned) must be pushed aside to reach the highest vantage point possible — he called that ‘Archimedean point’. That is the goal of the First Meditation.

I should probably mention that this blog entry is based on an essay I wrote for my philosophy class. For blog purposes, essay is too long & somewhat formal (a.k.a boring) to post it whole here so I will use parts of it and build upon it further by simplifying the premises/argument. First two meditations will be here and the rest in part 2 of blog.

Descartes' First Book Print on Meditations

Descartes’ First Book Print on Meditations

Descartes’ First Meditation

Descartes, in his analysis, has to bring his problem down to the absolute foundation. As mentioned above, he cannot allow his thoughts, biases, or beliefs to get in the way (he calls them ‘doubts’ as doubts are anything that can be questioned so that includes thoughts, opinions, biases, beliefs, etc). Anything that can be doubted cannot be used as the foundation to build other arguments on top of. Only when on a solid foundation can we look at things as they are without our opinions blurring things out.

Descartes’ first meditation is basically him doubting his senses. Keep in mind that much of what we do and know stems from our senses. In order to doubt his senses, he must show why his senses could be problematic and must be eliminated from consideration. He comes up with three possibilities with the goal of drawing doubts of our senses.

His first sub-argument stipulates that perhaps our senses are flawed. Our experiences very often do not coincide with reality and so if they are often unreliable, then they might always be unreliable. That leads to the possibility of illusion.

His second sub-argument stipulates that perhaps we could be in a dream state. When we are dreaming, everything in our dream seems real, and we usually cannot tell if we’re dreaming or if it is actually happening. Our senses cannot tell us that so our dreams end up feeling as if things in them are truly happening.

His third sub-argument stipulates that perhaps an evil demon or monster is playing tricks on us. We could simply be imaginary puppets being controlled by a demon, and our senses would not have any way of knowing, especially if it is an all-powerful being. If our senses are controllable, this all-powerful demon would have the power to create this world and everything around us without us being able to realize it.

The first meditation, as you can see, takes everything that can be doubted (including our senses) out of the way. If our senses could be deceitful, we must prove that we exist through other means — pure logic, which does not rely on any of our senses. Imagination is also out of the way as that could also be deceitful in trying to find out if we exist. This basically takes care of all our doubts except the ability to doubt itself.

At this point, Descartes can look at everything objectively without his doubts/opinions being involved (as opposed to subjectively, where his opinions blur things out). Side-note: I am not sure if true objectivity exists from our perspective as we are human and always will be human, but do not let that ruin the entire logic that Descartes sets forth!


Descartes’ Second Meditation

Now that we are down to the foundation and dropped our doubts (anything that can be questioned), the next question becomes: what do I know for sure? Only thing I know for sure, at this point, is that I have this interesting ability to doubt.

Recall that the ability to doubt is the ability to think. From that, we must follow the logic ‘If I have the ability to doubt things then I have the ability to think.’ If I am able to think, then I MUST exist. If I did not exist, then I would never be able to think on my own accord.

Photo by Todd Martin / CC BY /The Thinker

Photo by Todd Martin / CC BY /The Thinker

You may counter that argument with a question: How do I know I am able to think and that I am not simply manipulated to think that I exist by some evil demon? The way Descartes answers this potential issue is that a demon cannot make me exist if I truly did not exist. That means I would HAVE to exist, to begin with, if I am to be manipulated at all.

He considers couple other counter-arguments, but they are not strong counter-arguments. Very few refute Descartes’ argument up to & through the second meditation.

Descartes summarizes his findings perfectly in perhaps the most famous philosophical phrase: Cogito ergo sum (Latin). I think, therefore I am.

Note that this argument proves that the person making this argument exists but does NOT prove the existence of others. Just because I prove I exist does not prove that you exist too. Just because you prove that you exist does not prove that I exist too.

We have reached the ‘Archimedean point’ after proving my (or your) existence. Remember, ‘Archimedean point’ is simply a name for a metaphysical idea & logical concept that we can build everything else upon. It is named after Greek philosopher Archimedes; he claimed “he could lift the Earth off its foundation if he were given a place to stand, one solid point, and a long enough lever” (Wikipedia). Because I exist, my thoughts are validated as being my own thoughts (my existence is my foundation or the fulcrum), and from that I can balance my entire world (on a lever).



So, where are we at? What is the importance of these two meditations? Why is Descartes considered one of the greatest philosophers of all time?

The first two meditations are the most important as they define the methods of Descartes, and bring us down to the foundation where we temporarily throw out our opinions and acknowledge that we must must go beyond our senses. He shows how we exist as a thinking being through a purely logical argument.

Before Descartes, there were mainly two schools of thought – absolutism and relativism. Absolutism was the idea that everything we see or experience is exactly how it is, but it relies heavily on our senses. Descartes showed that our senses can be very deceitful. Relativism was the idea that everything exists in our own minds so reality and our existence might be completely different from person to person. I think Descartes would argue that relativism is flawed & rooted deeply on subjectivism, which the methods used in his argument is trying to push away from. Descartes moves away from these extremes into a new direction rooted in logic, which is why he is often considered the father of modern philosophy. More on these 2 trains of thought here: Philosophy of Science

Modern scientific method stems from the Cartesian method and the methods of Francis Bacon, which was essentially the early modern scientific method (It was not the first scientific method though as the first official scientific method dates back to the Islamic empires). Isaac Newton, Johannes Kepler, Galileo, Albert Einstein, Karl Popper and others made improvements since the 1600’s to Bacon and Descartes’ work.

The main reason why Descartes’ method was ideal for science was because the point of science is to go beyond one’s senses (‘objectivity’ if you want to attach a name). Our senses alone have the potential to mislead us into believing something that may or may not be true. The principles of logic that Descartes draws is based on a much stronger foundation than things such as our senses, emotions, our natural inclinations to judge others & ourselves, our need for belief in the supernatural, our animal instincts of survival, etc.

Descartes’ focus is on establishing the theoretical foundation first before anything (including devising arguments or making judgments on observations). In a later writing, Descartes makes 4 arguments summarizing his analysis method (Rehfeldt, 1993). First, he says to doubt everything – don’t hastily accept something without some sort of investigation. Second, he says to divide the problem into pieces so you are not trying to solve the problem as a whole all at once. Third, he says to solve the simplest pieces first “in order to rise little by little, or by degrees, to knowledge of the most complex, assuming an order, even if a fictitious one, among those which do not follow a natural sequence relatively to one another” (Descartes, 1637). Fourth, he says to “omit nothing” and to be thorough in the investigation. Time should not be a concern as investigation matters more.

Since then, most of these principles have been adopted by science. Descartes was also involved deeply in mathematics, which is central to physics. In fact, a lot of the work Isaac Newton did in creating calculus and other aspects of physics was inspired by Descartes and his work (Brackenridge, 1996). Of course, Newton took it to the next level far beyond Descartes (definitely will be a blog entry on Newton in future).


Descartes’ Third, Fourth, Fifth Meditations

Next part, I will look at Descartes’ controversial argument as it pertains to whether external objects exist beyond our own existence.

This will be in part 2 at : Descartes Part 2




Archimedean point. (2014, April 18). In Wikipedia, The Free Encyclopedia. Retrieved 00:45, January 7, 2015, from

Brackenridge, J. Bruce The Key to Newton’s Dynamics: The Kepler Problem and the Principia. Berkeley:  University of California Press,  1996. ‘’

Descartes, R. (1637). Discourse on the method of rightly conducting the reason, and seeking truth in the sciences.

Rehfeldt, T. (1993). Descartes and Scientific Method: Four Precepts. Retrieved January 4, 2015, from
For objections for Descartes’ arguments, see — I did not include objections in this blog entry.
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