Is Seeing Really Believing?

Photo by Giammarco on Unsplash

Materialism has long been a topic of discussion in philosophy over the ages, from Empedocles and Democritus being the founding fathers of materialism as a reaction to idealism, to contemporary materialists such as Hobbes and La Mettrie. Rene Descartes, however, gave the most complete explanation for materialism but also resisted the idea since he believed that it was incompatible with the evidence. In The Meditations, Descartes employs doubt as a powerful tool against the Aristotelian thought which placed a great emphasis on the suggestion that all knowledge comes from the senses, and argues that the immaterial mind, which exists separate from bodily senses, is the actual source of our knowledge. My argument is that Descartes would disagree that the best way to get to know about a thing is to apply all of our senses- to look carefully, to touch and feel, taste and smell, since he believes that our senses are not completely reliable. In this article, I will also expand upon my personal view of the relation between sense perception and knowledge and the implications of Descartes’ view of sensory evidence on modern science.

As a proponent of dualism, Descartes would disagree with the claim that the best way to know about a thing is to apply all of our senses because senses fail the test of certainty. Descartes uses the “method of doubt” for the purpose of rejecting all his opinions that could be false by finding in each of them at least some reason for doubt. Descartes questions the idea of sense perception as a reliable source of knowledge and states that knowledge is known by its certainty. Descartes mentions in the First Meditation that “whatever I have accepted until now as most true has come to me through my senses. But occasionally I have found that they have deceived me, and it is unwise to trust completely those who have deceived us even once” (1). How does reasoning do what our senses cannot? Descartes expresses his views in the infamous Latin phrase “cogito, ergo sum” or “I think, therefore I am”. This phrase concludes that if one is skeptical of existence, then that is in and of itself proof that an individual exists.

In my personal opinion, I believe that the relation between sense perception and knowledge is an important one, however, sense perception is not the best, or even the only, evidence for the nature of things. Similar to Descartes, I believe that the senses are not always reliable and that sense perception is a complex process that involves both sensation and interpretation. Sense perception can be broken down into sensation and interpretation, and therefore it incorporates a lot of selectivity and subjectivity. I do not equate these qualities with indubitability. The conscious mind can treat certain sensations as foreground whilst dismissing others as background sensations, and factors such as our mood can also affect the way we perceive the world through our senses. Moreover, sensory illusions are everywhere- from the “blue-black or white-gold” dress debacle from a couple of years ago to the Poggendorff illusion first reported in 1860. In my ordinary dealing of things, I share the view of sensory evidence on the condition that one sense perception should be confirmed with the evidence of a second sense, and that intellectual judgment goes hand in hand with sensory perception.

Modern day science agrees that the translation of input animal senses into seemingly non-physical experiences is known as thought and that the traditional model of our mental function has been that the senses provide separate data to our brains which are then translated into the appropriate mental phenomena. It has also been proven that cross-sensory experiences can take place, such as synesthesia or ideasthesia. Without a pre-existing concept of self, Descartes would not have had an “I” to attribute the thinking to. Moreover, without a pre-existing network of interrelated and distinct concepts, our sensory experience of the world would be an undifferentiated clump rather than discrete objects we can fully comprehend. Due to this, I believe that scientists today would most likely share a refined version of Descartes’ view of sensory evidence, and rethink what this new model of consciousness means for our understanding of ourselves and our relation to the sensory perceptions around us. I also believe that Descartes is calling science to a higher standard by questioning the heavy reliance on sensory observation and arguing that scientific endeavors should be strictly carried out by tracing logical connections between ideas of the intellect.

When thoroughly analyzed, Descartes’ First Meditation provides ample evidence that he would not agree with the statement that our sensory perceptions are our best evidence for the nature of things since the senses can occasionally be deceiving. The relation between sensory perception and knowledge is a complex one and modern science has built upon Descartes’ theory to develop a better understanding of self and sensory perception.



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Rija Asif

Rija Asif


An electrical engineering student with a love for writing about tech, society and literature, as well as talking about herself in the third person.