Kenny, Anthony. Descartes: A Study of His Philosophy.
Universal doubt starts with doubting one's senses. An objection to this is the necessity of reliability to detect an error. Descartes agrees though the measures for reliability are innate and rest with the intellect for him. The validity of innate ideas, in the end, depends on the veracity of God--which also explains the use of evil genius to argue for the skeptical position.
The cogitare embraces all kinds of thought processes including the two major modes, which are sense perceptions and volition. Thus, as soon as I think, even if I am not sure about this cogitare, it cannot be doubted that an I--though in itself not clear--is. Descartes supports this with an indubitable "natural light" principle, namely, that a property necessitates a substance.
In addition, the cogito ergo sum implies a sum res cogitans, meaning that being's essence is thinking whereas res is the scholastic substantia (concrete entity). For Descartes, there are only two substances: the mind with the essence of thinking and the body with the essence of extension.
Kenny then investigates the two modes of consciousness, whereas sense perception is a mode of consciousness and a conscious act; whereas volition only is the latter. He concludes with Hobbes that, for Descartes, conscientia, defined only as awareness, cannot make inference about the world. There is also no measure--Kenny refers here to Wittgenstein--that ensures that there is content of thought.
Descartes separates mind and body which requires exhaustive truth about both. Descartes, responding to Arnauld, only makes claims to the knowledge of complete things that is distinct from adequate knowledge (that would be unattainable absolute knowledge). Kenny argues that for one, complete knowledge might also be unattainable, and secondly, that this caveat might allow discovering connections between mind and body.
Descartes proves the existence of the world and God through the "property of ideas," thoughts, which are innate and include images. He thus establishes the first proof of God: the idea of a perfect God, based on ex nihilo nihil fit, can only be given by an existing God. Kenny only validates this conclusion if it can be proven that the idea is coherent which is done by Descartes through his idea of "objective reality" that contributes existence to perfection. For Kenny, the truth of this depends on the veracity of God.
The second proof of God, the ontological argument, implies that understanding "true and immutable" essences confirms a thing which does not necessitate its existence. Kenny clarifies this using Meinong's distinction between Bestand (subsistence) and Existenz (existence). Still, both can concur and need to concur for God, because absolute perfection includes existence for Descartes. For Kenny, there is a contradiction between the proof of the I as the necessary substance to the property of thinking and the ontological proof that assumes that there can be properties without substance.
Descartes holds a number of truths derived from "natural light," some are clear as such whereas other require removal of prejudice--which is a willed clear and distinct judgment. The validity of such truths hinges on a God who does not deceive which depends on the truth of the proof of the cogito and of God. Kenny sees the argumentative circularity and remedies it by the need of a measure for fallible intuitions. Still, this is not satisfactory for Kenny because we never have a guarantee that our ideas--the measure of our actuality--are truly clear and distinct due to our tendency to err without being aware of it.
For Descartes, matter is characterized by extension. It is divisible, in motion and abides by inertia. Other properties (accidents) lack a priori clarity. Kenny demonstrates that Descartes specifications about inertia and circular movement tend to create logical contradictions. Kenny also points out that Descartes acknowledges a connection between mind and body though this creates difficulties considering their essences.
Kenny's book is a meditation on Descartes meditations that is a valuable accompaniment to Descartes's work.--Erich P. Schellhammer, Royal Roads University.
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|Author:||Schellhammer, Erich P.|
|Publication:||The Review of Metaphysics|
|Article Type:||Book review|
|Date:||Mar 1, 2010|
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