Anselm: Does God exist?

St. Anselm (1033-1109) put forward a fairly straightforward argument in answer to the question: Does God exist? It is one of the classical arguments in Western philosophy. Just follow the cues to discover what his argument is.

1.
Start. Go to 2, 3, 4.

2. (from 1)
When an artist plans a work, the work exists in his understanding. When the artist executes his plan, the work exists in reality.
Go to 5.

3. (from 1)
God is a being "than which nothing greater can be conceived". [conceived = thought]
Combine with 5, go to 6. Also go weakly to 8.

4. (from 1)
A being that cannot be thought not to exist is greater than a being that can be thought not to exist.
Combine with 7, go to 8.

5. (from 2)
[Therefore] There is a difference between an object being in the understanding, and an object being in existence.
Combine with 3, go to 6.

6. (from 3 & 5)
Once one hears and comprehends this, God exists in the understanding.
Go to 7.

7. (from 6)
If God exists only in the understanding, then it is possible to think of a being that exists also in reality.
Combine with 4, go to 8.

8. (from 4 & 7)
This makes God not a being "than which nothing greater can be conceived". This is impossible (by hypothesis in 3).
Go to 9.

9. (from 8)
Therefore, a being "than which nothing greater can be conceived" must exist both in the understanding and in reality. This is God. God exists.
Go to 10.

10. (from 9)
End.


Primary source:
"Saint Anselm of Canterbury: The Ontological Argument" in Nicholas Capaldi (ed) et al, Journeys Through Philosophy, Prometheus Books, 1982, pp. 369-70.
[St. Anselm was the Italian-born Archbishop of Canterbury.]


Postscript on method
Most philosophy is written in prose. While this makes for fluent reading, it also makes the argument extremely opaque in both content and flow. Presenting the argument in syllogisms is fully transparent, but is extremely tedious both to write and read. This is my compromise mode of presentation. I call it "programmed philosophy".