In the essay "Philosophy and This Actual World," M. Benjamin assesses the argument of Rene Descartes and his description of the Cartesian subject. The Cartesian subject is "a pure (disembodied) subject of consciousness" (Benjamin 29). Before describing and considering Benjamin's argument, it is necessary to briefly outline the argument of Descartes. Descartes' philosophy was developed based on a process of doubt. He sought knowledge and truth by asking what could be known without doubt. In doing so, he rejected everything external to a person because it could not be known with certainty. He argued that anything that a person sees or perceives could be false. This includes doubting the existence of others. Descartes finds only one thing that can be known with certainty. This is commonly summarized by his famous statement "I think before, I am." Essentially, since you are doing the thinking, it is impossible to doubt that you exist. This is the one thing that you can be certain of. This conclusion forms the first certainty of Descartes' theory. From this one proven conclusion, further conclusions are then made about the world. There are many ways to approach Descartes' argument. The one that Benjamin uses is based on the language used by a Cartesian thinker. An assessment of Benjamin's argument will show that it is a valid one and that it does show a major flaw in the philosophy of Descartes.

             Benjamin assesses this argument by focusing on the language that it required for the argument to be made. He starts by asking "What would language have to be like if you were a Cartesian subject?" (Benjamin 29). He draws three conclusions about this. The first is that it would have to self-taught. The second is that the language would have to be private. The third is that there would have to be some way to determine that the words have meaning. Benjamin's argument is that a language is not possible for a Cartesian subject.