Descartes’ Meditations: Discerning Truth From Illusion
Imagine a world where our reality is in constant flux. Where yesterday’s tree is no longer a tree today because winter has stripped its blooming flowers and lush green leaves. Where the crescent moon stops being the moon because it is void of half its shape and illumination. In this world where sensible knowledge defines our reality, we have no understanding of the essence of the things around us, and thus no understanding of anything at all. In the “Second Meditation” of Descartes’ Meditations on First Philosophy, he explains that the only way for us to have knowledge of corporeal things is through the operation of our mind, not our senses. Sensory perception, he argues, is susceptible to inaccuracies that obscure our clear and distinct comprehension of an object’s true nature. However, one may argue that operations of the mind and senses are inseparable because, without sensory input, the mind has nothing to contemplate in the first place. To that, Descartes may respond with the notion that sensory knowledge only helps us confirm an object’s existence or reality, but it is the mind that truly perceives its essence. Ultimately, Descartes’ ideas regarding the metaphysics of knowledge help us perceive ideas with greater clarity and bring us closer to truth.
In the “Second Meditation,” Descartes uses the physical change of a piece of wax to present his case for why the essence of corporeal things can only be understood by our mind, rather than our senses. His first premise establishes that sensory knowledge of objects is unreliable and in flux. A piece of wax when it is cold is cold to the touch, solid, and has its own set of scents, shapes, and colors. However, these properties are gone as the wax warms up. Heat melts away the scent, shape, and hardness of the wax, and its size increases as it turns liquid and hot. As we attempt to agree upon a singular definition of what wax is, these disparate observations make it an impossible task. In contrast, Descartes’s second premise establishes that intellectual knowledge of objects produced by the mind is unchanging and reliable. Meditating on the wax’s physical transformation, he finds that the wax’s form is not solid but mutable; its size is not set but extended and flexible. Further, the wax’s mutable quality means that it is not limited to occupying just a few shapes like squares or triangles but an infinite number of shapes and forms; its size is also greater with the strength of heat melting it. No matter what kind of state the wax is under, it seems that these properties — mutability, extension, and flexibility — remain true for the wax, and thus knowledge produced by the intellect is consistent and reliable. And when we think about what the essence of something is, it is precisely the property that is unvarying and true every time for that corporeal thing. It follows from this last premise that only the mind can grasp the essence of corporeal things since only intellectual knowledge is constant.
An objection to Descartes may highlight that sensory knowledge’s inconsistency does not necessarily mean the essence of physical objects is perceived solely through the mind; without first observing the wax’s transition from solid to liquid, one cannot begin to perceive its essence because there is no initial concept to reflect upon. Thus, we arrive at truths about the corporeal world not just through the operation of the mind but also in conjunction with our senses. Let us imagine a person who has never encountered water in its various forms (liquid, solid ice, and gas stream). This person is then exposed to water in a controlled setting, first in its liquid form, feeling its wetness, coolness, and fluidity. Next, they witness water freezing into ice, and its respective characteristics like hardness and coldness. Finally, they witness water boiling into steam, transforming into an invisible form that spreads into the air. Through these sensory experiences, the person begins to form the concept of “water” as a substance that can exist in multiple states. With the concept of water now formed, the person can further engage in abstract thinking, pondering its molecular structure and why it changes states at certain temperatures. This abstract understanding — achieved through the mind’s operations — would not be possible without these concrete sensory examples.
In response, Descartes may contend that the operation of the senses only helps us confirm the existence of a physical object and not its essence since the idea of something cannot come from nothing. In “Meditation Three,” Descartes exemplifies the causal relationship between an idea and its reality. A stone, he writes, cannot begin to exist unless it is produced by something that also contains stone; similarly, heat cannot be felt by him unless it is produced by something that has at least as much. By this logic, we can also deduce that if we somehow feel coldness in heat, that sensation is false because there can be nothing cold in the cause of heat. Thus, Descartes concludes that the representation of things within our thoughts (their objective reality) must possess an equivalent degree of actual existence (their formal reality) as it cannot get its reality from nothing. Applying his reasoning in the context of the wax argument, Descartes would argue that the function of the senses merely allows us to recognize the wax’s formal reality — that it simply exists. They do not reveal to us that the wax possesses the qualities of mutability and extension.
The operation of the intellect, in contrast, lets us exclusively perceive the nature of the wax precisely and without differentiation. Using basic arithmetic as an example, Descartes shows that his “clear and distinct” method is a tool for ascertaining absolute truths. In the mathematical statement “2 plus 3 make 5,” there is nothing that we can doubt or reject because the sum of these two numbers is so apparent to our minds that any answer other than 5 would violate the fact that 5 is the sole result. Therefore, only ideas that are as evident and discrete as “2+3=5” can be confirmed as true and indubitable. Returning to the wax example, Descartes might clarify that the changing sensory qualities of the wax (its smell, color, shape, and sound) are not perceived clearly and distinctly because they are not obvious nor unique to the wax. Instead, the wax’s capacity to change while remaining the same substance is understood clearly and distinctly by the mind and is what makes the wax distinct from other substances.
In conclusion, Descartes’ idea that the essence of corporeal things is perceived through the operation of the intellect holds true because the operation of the senses only affirms an object’s being, not its essence. Although sensory knowledge of objects, exemplified by the wax’s transition from solid to liquid, is unreliable due to its variability, one can make the argument that it still provides the initial data for intellectual reflection. Thus, the intellect and the senses work in conjunction to discern the essence. However, since sensory functions lack the capacity to perceive an object in a clear and unambiguous way, only the intellect is able to discover its true nature. In the end, Descartes’ ideas not only encourage us to look beyond the superficial and variable nature of sensory input but also empower us to engage with the world in a more discerning and unbiased manner. This, perhaps, is the aim of the Meditations.
