Descartes" Examination of a Thinking Soul.
In order to truly understand the nature of the human mind as asked in the course syllabus one must be able to define a thinking individual, something that Descartes attempts and succeeds in achieving. In his Letter to the Marquess of Newcastle, Descartes rejects others" belief that animals have reasoning or thoughts and devices a sort of test based on a defining characteristic of a thinking mind that he believes can successfully separate the thinking from the non-thinking. Descartes thoroughly seeks for a distinguishing feature that separates an animal mind from a human mind and comes to the conclusion that an "external action", more specifically the capacity for linguistic activity is the difference.
According to Descartes, defining a thinking creature is ultimately decided by the "external action" of linguistic capability; however, Descartes makes certain that actions that are inane, for example, are not included. In this passage, Descartes" idea of "external actions" is not simply the ability to eat, talk or walk (explained further later) but rather a more complex action that incurs more complex thoughts: the capacity for linguistic activity. However, Descartes does not simply define linguistic activity as talking but as " words, or other signs that are relevant to particular topics without expressing any passion" ("Letter to the Marquess of Newcastle," CR, p. 36). In Descartes" Discourse on the Method of Rightly Conducting One's Reason and Seeking the Truth n the Sciences, he first suggests a test to see if there is a separation of body and mind which includes such things as if the candidate is able to respond verbally, produce different arrangements of words so as to give appropriate, meaningful answer to questions and whether it can engage in a rage of appropriate, rational activities (CR, pp.34-35). Here, however, Descartes goes a step further as he devices a test to differentiate between a thinking and non-thinking mind.
