The idea that humanity can be sure of the knowledge that it has is generally taken for granted. Skeptics have pointed out that it is, in fact, impossible to know reality in any significant way and be relatively sure that this knowledge is legitimate. Since this argument was made, philosophers have attempted to overcome the need to establish some basis for knowledge that they could be sure of. While those such as Descartes used pure reason in order to come to some basic conception of reality, thinkers such as Locke and Kant focused primarily on empirical knowledge in order to build a foundation of understanding reality.
Rene Descartes's argument regarding reason dictates that when divorced from the potentially misleading experiential sensations that people have they are able to use their rationality in order to come to higher forms of ultimate truth. He argued that the reliance on experience and the natural world would inevitably lead to misconceptions regarding what is true and what is not. Descartes uses pure reason in order to overcome skepticism. He argues that because he is able to think then, at the very least, he must exist. From here, he is able to use rational thought, without any empirical information, in order to develop his understanding of reality. He uses the ontological argument in order to establish the existence of God and then uses God's existence to demonstrate that the experiences that people have can be trusted, due to the fact that God would not deceive.
For Descartes, this was an absolute foundation of truth that could be established through the application of pure reason. The use of rational thought in order to come from a point of pure ignorance and skepticism to the point in which he could argue that there was some amount of fundamental knowledge that humanity could be sure of. His philosophical inquiries fundamentally divorced mind and body. This distinction would be upheld by philosophers that followed him. Others, however, would focus on the use of empirical experiences in order to establish a foundation for understanding reality.
John Locke fundamentally challenged the notion that knowledge could be obtained without any experiential information. Locke's philosophy of reason is based on the principle that there can be no innate ideas or characteristics. All knowledge flows from empirical ideas. The impressions of nature and the observations that we have of objects is the underlying faculty by which understanding is formed. Locke argues against the notion of universal truths, which would have to be an innate or underlying requirement of reality, in order to actually exist. He argues that, while certain principles or moral ideas may be universally agreed upon, this does not necessarily make them innate. He demonstrates that these agreements can be shown to be established without the use of innate knowledge. This is evident in the fact that certain forms of mathematics or higher forms of philosophic thought might not be comprehensible to young, or stupid, people.
Locke's theories are based on the notion that the mind begins as a blank slate, or tabula rasa, which is then impressed upon by the various experiences that the individual has throughout their life. These impressions are able to help the individual form more complex modes of thought through empirical observation. Rather than being imprints on the soul that have been there since birth forms of universally agreed thought are the result of the imprint of reality upon the mind through experience. For Locke, certain perceptions will naturally result in the understanding of certain truths. For this reason, people are able to come to agreement on these principles. Reason for Locke is therefore the result of experience and the application of rational empirical thought to these experiences (Locke).
Much like Locke, Immanuel Kant expounded the notion that experiential, rather than innate, knowledge was the method by which the mind could come to understand the world. Kant looked at how much about the world could be known through a lens of pure reason. However, Kant also believed that there could be a distinction drawn between empirical and innate knowledge. While knowledge is primarily the result of experiences, the human mind is capable of exerting reason in order to establish certain truths that exist outside of experience. This includes mathematical and scientific knowledge, which a person might be able to come to despite the experiences that they have had. However, this type of knowledge does require impressions of the real world (Kant).
For Kant, knowledge that is universally applicable to any situation can be distilled from the synthesis of knowledge. Kant is a realist, however, and does not attempt to extend his view of rational thought to the capacity of metaphysical or moral thought. He believed these ideas to be messy and outside the scope of rational understanding. He argued that, because a human being is able to extrapolate ideas such as “infinite” from those such as “finite” and abstract these concepts to higher forms of meaning, then there must be some sort of faculty of rational thought that allows for the understanding of universal principles. Kant argued that if people were not able to use rational thought then experience would just be a jumble of sensations that we could not make any sense out of.
Works Cited
Kant, Immanuel. Perpetual Peace: A Philosophical Sketch. 1795. Print.
Locke, John. An Essay Concerning Human Understanding. Book I: Neither Principles Nor Ideas are Innate. Print .
