In the early part of the Meditations, it has been quite clear that Descartes was very much leaning towards solipsism, a philosophy that asserts only the self exists. This is what makes his rationalism quite unique. His rationalism put everything under radical doubt. He had earlier on declared that he exists only because he thinks and doubts things. To put it simply, he exists because he thinks he exists. His being a thinking being is proof because if this were not the case, then he would not have perceived it in the first place.

This assertion of his is already quite problematic. The argument is circular, in that there is not enough grounded evidence in which the conclusion, that is he exists, can spring from. Though he had differentiated this from a state of dreaming, to simply assert oneself as existing because one is aware, although quite optimistic, is nonetheless not enough to support the claim. It is not the same as saying that one is feeling hungry because of the feeling of pain in the stomach and other bodily functions connected to making the brain realize that one is in a state of hunger.

Had Descartes accepted the notion of the senses playing a part of a person’s clear and certain knowledge of the world, then simply being conscious of one’s existence through thinking might be more reasonable, since the brain would be sending signals or at least contemplating about itself, which is a distinct characteristic of man being a rational being.

To simply rely, however, on one’s own reason and rejecting anything coming in from the senses is realistically impossible. For certitude does not simply come into us without having a prior experience about it.

He says his senses are deceiving him because of the idea of something within him seems not the same as the object he sees through his senses. He uses as an example the sun, wherein his idea of which is a giant fiery ball of flame and in actuality, he simply sees it as a speck in the sky, only about a third or so larger than the moon. This is a poor example, given that there exists then sciences explaining such phenomena. Yet his conviction remains the same. A thing might be something else than what it seems but how can we perceive its true form if not through the senses? Would Descartes know that the sun was a big fiery ball of gases had it not been for empirical sciences saying such? He says that he is grounded on the natural light of reason and yet seems to derive his conclusions through the use of empirical data.

Given Descartes’ radical doubt, up to the point that he even doubts memories, indeed the only thing that one can be certain about is that one is doubting and trying very hard to think about what there is to doubt and what there is to believe as clear and distinct. Yet Descartes is certain of another thing aside from doubting and this is the idea that there is a God.

In his third and fourth meditation, he comes across the possibility of error occurring to him even within the natural light of reason, and of the problem of whether or not God exists. Conversely, if God exists, he pondered if it was possible that this almighty being be deceiving him.

He begins his thinking that there is a God who created everything by saying that everything that has been created must be in some way, coming from something else which possess the qualities or modes that is the same with the thing created. A stone, he said, can begin to exist only if it is produced by something that contains—either straightforwardly or in some higher form—everything that is to be found in the stone; similarly, heat can’t be produced in a previously cold object except by something of at least the same order of perfection as heat, and so on(Ariew & Cress, 2006).

He adds to this that his ideas of a stone or of heat cannot simply come from him alone but from something else that has these qualities. Such ideas are but mere representations of a reality, much like what a photograph would do as a representation of an event. And since such is the case, there must be something, he says, in which all those ideas originate from since there cannot be an infinite regress of ideas.

Ideas, in themselves, are not false since they are not from the senses. Even ideas of other men, angels and of God, as Descartes had put it, even if all three did not exist, are real ideas. So long as these ideas are not from the senses, Descartes regards it as clear and distinct. However, there are false ideas for him. The notions of hot and cold, colours and the like that represent non-things, are false in that they are materially false.

Regardless, all the ideas that Descartes think about, whether they are materially true or materially false, he asserts to have come from God. He says this because he had, from before his elucidation, thought that things coming from the senses are real. Now, through the use of the natural light of reason, Descartes perceives them as false. He has greatly erred, so to speak.

Then, if he is someone who is both incomplete and commits error, there must be something out there that does not. God existed because he has a notion of an imperfect being (himself), and there must be, from this idea of imperfection, something that is perfect from which the imperfection is derived. Since he is a thinking thing, he must have come from something that is also a thinking being, although much greater than him.

Descartes adds that the idea of God did not come from the senses nor did he spontaneously created it because if these were the case then he would have been able to manipulate the idea. However, he cannot do this to his idea of a perfect being. and if there is a God, can this almighty being be deceiving him?

Descartes answers that it is not possible because a perfect being cannot do something that is out of its nature, which is everything good. Error stems from judgments which in turn, is a product of a person’s free will and from a perception of a thing due to one’s senses.

This is another circular argument from Descartes. In line of theology, it could be applauded but in the realm of philosophy, more or less, it has its loopholes. For one, it is too assumptive. There exists a cause of everything, truly, but the idea of God is anyone’s guess. To simply state that there is a God because one is imperfect and therefore must have come from a perfect being is, just like his argument for existence, without much proof.

Another is his argument that the perfect being is necessary because it is an uncaused cause. Surely, this is true because there is no infinite regress but the first cause is not so much important as the second one, or the third or the fourth or even the last cause of the other cause. To put it, these series of causes are important in each and every aspect just as the first because it is a series of causes that without one of these, the end result would not have happened.

Conclusion

I assert then, that in Descartes’ thinking, there is something lacking. In his methods, it is as if he simply grab things out of thin air and claim them to be true and distinct because, to put it, they had been grasped only by the intellect. To not rely on our senses in the physical world is something that we should try to shy away from. Even the Eastern philosophies, particularly that of the Indian civilization, accepted that though the world is not ultimately real, it is real in the practical sense.

Nevertheless, a strong point in Descartes’ thinking is that like all great philosophers before him, he had produced a new mindset for future generations to ponder upon. His esteem of the capabilities of the intellect perhaps cannot be compared to any other.

Yet to rely solely on the intellect is a brave feat but nonetheless ungrounded. His claim of treating something as clear and distinct because it is obvious, when we think about it, is not really on par with reality. Descartes’ emphasis on the human mind to be the sole tool for determining whether or not an idea or an object is clear and distinct is perhaps one that overestimates the capabilities of the mind if not giving it a heavy burden.

But that is why we called Descartes’ philosophy radical, isn’t it?