Analysis of information sources in references of the Wikipedia article "Norman Malcolm" in English language version.
Though no one pointed this out explicitly until Norman Malcolm in the mid-twentieth century, Bonaventure and Aquinas alike seem to have recognized that Anselm in fact developed two distinct versions of the ontological argument.[42] Malcolm distinguishes them as follows: Anselm's "first ontological proof [in Pros. 2] uses the principle that a thing is greater if it exists than if it does not exist. His second proof [in Pros. 3] employs the different principle that a thing is greater if it necessarily exists than if it does not necessarily exist."[...] [42] The first person to explicitly flag that there are two distinct arguments in Prologion 2-3 was Norman Malcolm, in "Anselm's Ontological Arguments," 44-46.
