Descartes' Ontological Argument: Premises & Criticism

Instructor: Joshua Sipper

Dr. Sipper holds a PhD in Education, a Master's of Education, and a Bachelor's in English. Most of his experience is in adult and post secondary education.

Rene Descartes (1596-1650) is still considered one of the world's most revered philosophers. His extension and expansion of St Anselm's ontological argument is still held in high regard today by philosophers of all branches.

Descartes Ontology

Ontology is a word used by philosophers to describe the study of being or whether or not something or someone exists. Many philosophers have used ontology over the millennia to discuss the existence or being of everything from matter to morals to human beings. But the one being philosophers seem most interested in discussing is God. Descartes was no different. He takes much of his ontology from St Anselm (1033-1109), a monk who lived in France and England. St Anselm's ontological argument has been modified and changed by many philosophers over the centuries, but Descartes is considered to be one of the key philosophers as far as capturing and furthering the essence of the argument.

Rene Descartes was a famous philosopher, scholar, and mathematician. His ontological argument is seen as one of the most concise and elegant in history.
Descartes Portrait

Descartes Argument

Descartes builds upon the original Anselmian ontological argument which is laid out as the following:

1. No being can be conceived that is greater that God

2. This being either exists in mind, reality or both

3. If the being only exists in the mind:

a. Existing in mind and reality is better than only in the mind

b. This being existing in the mind can be conceived to exist in reality

c. If the being exists in mind alone, it is not the greatest to be conceived

4. Therefore this being must exist not only in the mind but also in reality

Descartes takes the argument to another level. This is how he puts the argument:

1. If God exists, He must be perfect

2. A perfect being is perfect in every way

3. Existence itself is a perfection

4. So, God must possess the attribute of existence necessarily. God exists.

There are similarities in both ways of stating the ontological argument, but it's easy to see that Descartes puts more emphasis on the nature of being than the state of being. In other words, Anselm was more concerned with the way in which God exists; whether in the mind or in reality or both. But, Descartes looks more deeply into the quality or nature of that existence. One argument isn't necessarily better than the other, but both are important to consider.

Ontological arguments revolve around the state or nature of being.
Ontological Committments

Criticisms of Descartes's' Ontological Argument

As with any philosophical argument, philosophers of opposing viewpoints always seek to critique the argument. This is not only important but often welcomed by the argument's champion since critiques help to point out inconsistencies which help the originating philosopher to refine his or her argument.

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