Jan Baptist Weenix. Portrait of René Descartes. 1647-1649.
One of the arguments for the existence of God that modern Humankind finds most difficult to understand is the ontological argument. This argument takes the concept of God, then argues on that basis that God must exist.
The first step in the argument is the assertion that the concept of God is innate within us. In other words, this is something that rational people recognize. (The historian of philosophy Frederick Copleston writes, “All clear and distinct ideas are innate. … for Descartes innate ideas are a priori[prior to experience] forms of thought which are not really distinct from the faculty of thinking.”) The innateness of the concept of God means that we recognize this concept through a purely mental insight, the same way that we recognize the facts of mathematics and of geometry.
The next step is to say what the concept of God that we recognize is. According to Descartes, the concept of God that we recognize is that of “a supremely perfect being.” In other words, God is the most perfect being. (Saint Thomas Aquinas would say that only through our awareness of the most perfect being can we be aware of the differences of quality among other objects and beings; for example, only because of our awareness of God, in whom all perfections reside, can we be aware that one horse is qualitatively better than another.)
Next, we must show what our clear and distinct idea of God can tell us about God. Descartes uses the example of geometric objects such as triangles and squares here. These geometric objects do not exist physically in the universe, yet we can talk meaningfully about them, and in fact, we can even develop theorems about them. One famous example is the Pythagorean theorem that “the square of the length of the hypotenuse of a right triangle equals the sum of the lengths of the other two sides” (The Concise Columbia Encyclopedia).
As Descartes points out, “… it follows, from my mere ability to elicit the idea of some object from my consciousness (cogitatione), that all the properties that I clearly and distinctly perceive the object to have do really belong to it.” In other words, our mental conception of a triangle can tell us some of the qualities of the triangle. For example, when you conceive of a triangle, you conceive of a three-sided geometric figure. In addition, you can go on to understand the theorems, including the Pythagorean theorem, concerning triangles.
Now, as we have already pointed out, we have an innate conception of God, in which we clearly and distinctly perceive that God is “a supremely perfect being.” By examining this concept of God, we can learn about God’s characteristics.
If we were to list the qualities of perfection, which of course are the qualities that the supremely perfect being — God — has, we would have to list omnipotence, omniscience, and omnibenevolence. In addition, Descartes says, we will have to list existence, because existence is a perfection. Since a most perfect being has all perfections, God will have the perfection of existence.
But is existence a perfection? Descartes definitely thinks so. After all, imagine two artistic masterpieces: one is still in the mind of the painter, while the other is actually painted on canvas. Which would you rather have in your collection of fine art? (Another example: What would you rather find in your pocket? A real, existing $100 bill, or an imaginary, non-existing $100 bill?)
Descartes believes that existence is a necessary part of the conception of God. When we think of a triangle, we must think of a three-sided geometric figure. Similarly, when we are truly thinking of the supremely perfect being, we must think of a being who possesses all perfections and who therefore must actually exist. According to Descartes, when we reflect on our innate idea of God, we clearly and distinctly perceive that existence is part of God’s essence — that is, we clearly and distinctly perceive that God must exist.
In Descartes’ words: “It is not within my power to think of God without existence (that is, of a supremely perfect being devoid of a supreme perfection), though it is in my power to imagine a horse either with or without wings.”
In brief, this is Descartes’ ontological argument for the existence of God:
P1: I have a clear and distinct innate idea of the essence of God.
P2: My clear and distinct innate idea of the essence of God is that God is a supremely perfect being.
P3: Things that I clearly and distinctly perceive are true.
P4: God’s essence is that God is a supremely perfect being (from premises 1-3).
P5: A supremely perfect being has all perfections.
P6: God has all perfections (from premises 4 and 5).
P7: Existence is a perfection.
C: God exists (from premises 6 and 7).
This argument applies only to God because God is the only perfect Being. In God alone does existence belong to essence. (In God alone does essence prove existence.) Existence is not a part of the essence of a winged horse such as Pegasus; however, existence is a part of the essence of the supremely perfect being.
Note: The quotations by René Descartes that appear in this essay are from his Philosophical Writings, edited by Elizabeth Anscombe and Peter Thomas Geach (copyright 1971 by the Bobbs-Merrill Co., Inc.).
Copyright by Bruce D. Bruce; All Rights Reserved
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