Rene Descartes, a rationalist and John Locke, an empiric have a lot of contrasting and common features. In their philosophical writings, they answer questions about the knowledge of asking, what a man knows and his possibility to know. However when answering these questions, their approach is from different angles. Descartes finds out certainty and continues from this point.
Locke on the other hand employs empiric thoughts to advance through various levels of truth to arrive at certainty. Through this approach, Locke tries to establish truthfulness with each new step. As Locke argued, applying experimental knowledge without reason makes a person to be stuck. Moreover, rational knowledge is meaningless if not used together with knowledge from the senses. Though their work may contrast on certain aspects, it has been influential even in the midst of scientific advances.
Innateness of ideas
According to Locke, innate principles do not exist. By arguing in this line, Locke does not oppose Descartes, but targets some of his followers who supported the idea that almost all knowledge in man has basis in innate principles, an approach contrary to the Cartesian approach. In his platonic argument for innate ideas, Descartes puts it that we do not come across things like circularity and justice in actual environment of senses experienced.
Descartes’ arguments for innateness in the concept of God is platonic because he points out that the idea of deriving God from experience is impossible because experience does not present us with infinite perfection at any time. Locke on the other hand tries to contrast the platonic rationalistic argument of Descartes regarding circularity and justice. In his abstraction doctrine, Locke asserts that even though man fails to come across perfect circles, circularity may be common to all objects (Locke I.1.2).
By distinguishing between simple and complex ideas, Locke tries to contrast Descartes. Locke argued that man experiences less of God and abstract but more of constituents which are simple in God’s complex idea (Locke I.1.1-3). It occurs as if Descartes expected this response as he (Descartes) puts across the simplicity of God’s idea, an argument which is not sufficient to contrast Locke’s empiric view (Cummins notes).
“Innateness is no guarantee of truth” is an argument which Locke fails to put across but he assumes that “whatever is innate is true” (Locke I.1.4). Therefore, Locke does not directly argue that innate things are from God, a fact which is true. The above argument implies that to a certain extent, Locke’s argument is similar to the pre-Cartesian argument propounded by rationalists that justification is arbitrary (Hospers 10).
Locke’s argument that “whatever is innate is true” means that he holds a position similar to Descartes that if innate principles were to occur, then it would be the work of God, a position which is true (Locke I.1.1-3). Furthermore, if Locke were to argue fully against his position, then he would lack the foundation or basis to reject innate principles. However, though Descartes’ argument about innateness of God’s idea is complex, he admits that innateness cannot be self evident (Hospers 13).
Locke points out that structures existing in a child cannot be innate ideas. Therefore according to Locke, man lacks innate ideas at birth but can acquire these ideas by experience through observing things in the environment (sensation) or reflection in the mind. Moreover, the power has ability to repeat, distinguish and unite various simple ideas e.g. taste and texture.
The above argument is emphasized by Locke’s writings where he asserts that “…the ideas they produce in the mind enter by the senses simple and unmixed … the hand feels softness and warmth in the same piece of wax; yet the simple ideas … are as perfectly distinct as those that come in by different senses” (Locke I.1.4).
Furthermore, Locke points out that these simple ideas put together form complete ideas (concept of filling a bank slate or tabula rasa). For example the complex idea of a banana in the mind is a result of the mind combining several simple ideas about the color yellow. This is also emphasized by “Though the qualities that affect our senses are, in the things themselves, so united and blended, that there is no separation between them” (Locke II.1.4).
According to Descartes rationalistic perception however, it becomes hard to imagine what has not been experienced in the senses as asserted by Locke. Locke’s empiric thought unlike Descartes rationalist is absurd because it is absurd and difficult for mental ideas to be connected to objects in the environment (Cummins notes).
Knowledge, Reason and Experience
While Descartes argues that from the possibility of knowledge being obtained from reason, Locke employs an empiric thought that the sole source of knowledge is experience. Locke also notably criticizes the Cartesian view on knowledge basing his criticism on the fact that at first, the mind is similar to a bank slate (tabular rasa) which is filled through generation of ideas by experience.
Locke’s perception of a tabula rasa is in direct contrast with the Cartesian point of view of existence of innate ideas. Therefore, according to Locke’s empiric thought, knowledge can be achieved solely through experience (Locke II.1.7).
In contrast to Locke, Rene Descartes, a renowned rationalist asserts that it is through reasoning that a person can acquire knowledge which confers ability to discern true and false. This is in contrast to the empiric thought that the source of knowledge is experience (Cummins notes). According to Descartes, experience can cause deception of sensory organs with the way a person perceives objects hence cannot be relied on as a source of knowledge e.g. the false deception that a pencil inserted in water is broken (Hospers 5).
Descartes uses the above method to point out that a person should ignore judgement due to experience with objects unless proven beyond reasonable doubt. He uses this method to arrive at his method of establishing doubt (Hospers 77).
On the other hand, Locke’s method of arriving at his empiric view is in his work of an ‘epistle to the reader’ where he traces the roots of his philosophical empiric thinking. He uses an anecdote about conversations which showed him that for men to pursue knowledge, they suffer because of failure to determine understanding limits (Locke III.2.6).
From Locke’s argument, the origin of knowledge is through introspection and our senses (Locke II.1.3) though Descartes uses the methodical doubt approach of “I think, therefore I am” or “cogito ergosum” to refute Locke’s view though he points out that “Except our own thoughts, there is nothing absolutely in our power” (Hospers 31). This approach used by Descartes is however proof of the source of knowledge i.e. introspection.
Locke, John. An Essay Concerning Human Understanding. 6th ed.1689. Institute of Learning Technologies. Web. 8 Oct. 2011.
Cummins, Robert. Notes on Locke: Essay Concerning Human understanding.2009.Print.
Hospers, John. An introduction to philosophical analysis. Routledge, 1997.Print.