In Oppy (1995c), I divided the ontological arguments that I examined into six classes: (i) definitional arguments, (ii) conceptual arguments, (iii) modal arguments, (iv) ‘Meinongian’ arguments, (v) experiential arguments, and (vi) ‘Hegelian’ arguments. While I claimed neither that this taxonomy is mutually exclusive nor that it is exhaustive, I did note that I knew of no purely a priori argument for the existence of an orthodoxly conceived monotheistic god that did not belong to at least one of these categories. For each of these categories of argument, I exhibited arguments from that class and gave a detailed account of what I took to be shortcomings of the exhibited arguments. Moreover, I gave a fairly carefully qualified argument for the conclusion that there could not be a successful ontological argument that belonged to any of the six classes that I had identified. Finally, among other things, I provided an account of the use of parodies in the discussion of ontological arguments.

Since I wrote that earlier book, I have come to have some further misgivings about the general objection to ontological arguments, that is, the ‘carefully qualified’ argument for the conclusion that there could not be a successful ontological argument that belonged to any of the six classes of ontological arguments that I had identified. Furthermore, I have come to think that there are various ways in which the discussion in that earlier book is seriously incomplete.