In the 1,000s AD, Anselm, Archbishop of Canterbury, England used natural theology in an attempt to prove the existence of God. Using an ontological approach, Anselm began with the concept of God as the “greatest conceivable being.” Anselm believed that once people understood the concept of God, they would realize that such a being must exist and so recognize the existence of God.
Alvin Plantinga might be the greatest Christian philosopher living today. He refined the ontological argument and made it more effective. For the next few blogs we will be using Alvin Plantinga’s ontological argument for God’s existence.
This argument uses a phrase “possible worlds” that we need to understand. In philosophy, “possible worlds” does NOT refer to a possible planet or universe. It simply refers to various descriptions of reality that could conceivably or potentially exist. In other words, it’s possible that things could be configured differently and this present reality is not the only one that could possibly exist.
A SET OF PROPOSITIONS
Imagine a series of individual propositions that might describe a possible world:
A = John likes ice cream.
B = The earth is round.
C = Susie works in a factory.
D = The sun rises every day in the east.
Think of a “possible world” as being the conjunction or summation of all these individual propositions (A + B + C + D . . . ). Add, take away or change one proposition and you have a different “possible world.” Only one of these alternatives (one set of propositions) describes the actual world that we presently live in.
EACH PROPOSITION IN A POSSIBLE WORLD MUST BE TRUE AND MUST NOT CONTRADICT THE OTHERS
As we consider these potential realities, there are guidelines that limit the range of possibilities.
In any “possible world” (set of propositions that describes a potential reality):
1. Each individual proposition MUST be true, or that world (description of reality) is not really possible. For example, the idea that “the prime minister is a prime number” is a false statement and could not be a proposition in ANY possible world.
2. All of the propositions that together comprise a “possible world” CANNOT conflict with, or contradict, one another or else, once again, that description of reality is not possible.
Also, a proposition must use terms that are coherent. It would NOT be coherent if it referred to a phrase like a “square circle” or “married bachelor.” However, since the concept of “God” is a coherent idea, an ontological argument begins with the assumption that a “greatest conceivable being” exists in some possible world (i.e., in some description of potential reality).
A MAXIMALLY GREAT BEING
“Maximal excellence” exists in any being who possesses the “excellent-making properties” of:
2. omnipotence and
3. moral perfection.
“Maximal greatness” exists in any being who possesses these properties in EVERY possible world. “Maximal greatness” refers to the same thing as a “greatest conceivable being.” This being would be all-knowing, all-powerful and morally perfect in every possible world.
Plantinga begins with this assumption: “There is a possible world in which a ‘maximally great being’ exists.” But to be “maximally great,” God must possess the three “excellent-making properties” in EVERY possible world, including this actual world.
THE ONTOLOGICAL ARGUMENT FOR GOD’S EXISTENCE
Now that we understand the concepts of a “possible world” and a “maximally great being,” our next blog will explore Plantinga’s argument as shown here:
1: It is possible that a maximally great being exists.
2: If it is possible that a maximally great being exists, then it exists in some possible world.
3: If a maximally great being exists in some possible world, then it exists in every possible world.
4: If a maximally great being exists in every possible world, then it exists in the actual world.
5: If a maximally great being exists in the actual world, then a maximally great being exists.
Conclusion: Therefore, a maximally great being exists.