Lecture 1 – Anselm’s ontological argument

St. Anselm of Canterbury (1033-1109)
•	Born in Aosta, in Piedmont area of what is now Italy.
•	Benedictine monk, became abbot of Bec monastery in 1063
•	made Archbishop of Canterbury in 1093
•	exiled by William II and Henry I due to conflicts over secular vs. spiritual authority
•	called by some the “Father of Scholasticism”
•	known for careful, painstaking methods
•	held that there could be no genuine conflict between faith and reason.
•	Proslogion I:  “…rather than seeking to understand so that I can believe, I believe so that I can understand.  In fact, one of the things I believe is that, ‘unless I believe, I cannot understand’ [Isa. 7:9].”  Anselm held that faith alone was not enough; the task imposed by belief was the necessity of showing one’s beliefs to be rational.  Held that God “reward[s] faith with understanding.” 
•	ontological argument a useful heuristic to separate rationalists from empiricists.  Descartes, Spinoza and Leibniz accepted some version of it.  Aquinas, Hume and Kant rejected it.
•	If the ontological argument works, it not only proves Gods existence, but also reveals atheism as a logically impossible position.

Anselm begins with his definition of God as “that than which nothing greater can be conceived.”  Even the Fool who has said in his heart that there is no God can hold in his mind this idea of “that than which nothing greater can be conceived.”  As such, the entity so defined exists at least in intellectu.  Regarding the ontological status of such an in intellectu being, Anselm likens it to the idea that a painter has in his head of the painting that he has planned but not yet executed.  Once he has completed the painting, it exists not only in intellectu but also in re, that is in mind-independent reality.  Anselm reasons that any being that exists both in intellectu and in re in this wise is greater than one that exists only in intellectu.  But ex hypothesi, God is that than which nothing greater can be conceived.  As such, He too must exist both in intellectu and in re.  For, if He existed only in intellectu, then we would be able to conceive of something greater than Him.  That is, the being than which nothing greater can be conceived would be something than which something greater could be thought.  But this is impossible.  Therefore, He must exist both in intellectu and in re.  (Note that this argument takes the form of a reductio ad absurdum in which the supposition that that than which nothing greater can be conceived exists solely in intellectu is shown to entail a contradiction.)
	Anselm continues on to argue by the same reasoning that not only does that than which nothing greater can be conceived exist both in intellectu and in re, but it cannot even be conceived not to so exist.  For, we can conceive both a being than which nothing greater can be conceived that can be thought not to exist, and one that cannot be thought not to exist.  Clearly, a being that cannot even be thought not to exist is greater than one that can be conceived as not existing.  God must therefore be the former since He is that than which nothing greater can be conceived.  For Anselm, God is the only necessary being.  Every other being can be conceived not to exist, and is therefore contingent.  For God alone is it the case that His non-existence is inconceivable.  He not only exists but exists necessarily.  It is thus the case that, of all beings, God possesses the good of existence to the highest degree.  Anselm observes that this is most appropriate for, were it not the case, then someone would be able to conceive of a being greater than God.  If this were possible, then “the creature would be above its creator and would judge its creator – and that is completely absurd” (Proslogion III).
	This raises the problem, however, of just how it is that the Fool is able to say in his heart that God does not exist.  According to the argument of Proslogion III, this should be impossible.  Anselm addresses this issue in Ch. 4 by drawing a distinction between two ways in which someone can think something.  On the one hand, we think about something when we think about the word that denotes it; on the other hand, we think about something when we think about the thing itself and not a sign for the thing.  When the Fool thinks that he can conceive of a God that does not exist, he is thinking in the first sense.  That is, he holds the words in his heart, but not the thing signified by the words.  We cannot think about God in the second sense until we understand the concept of God.  And, once we understand the concept of God, it is impossible for us to conceive of Him as non-existent or contingent.  While this, on the face of it, addresses the tension between what the Fool has said in his heart and the necessary existence of God, it seems that one might further argue that a being that cannot be conceived not to exist, even when thought of in the first sense (that of the Fool) is greater than one which can be thought (in the first sense) not to exist.  It is not at all clear what reply Anselm could furnish to such a criticism.