 Such ‘strict identity’ is virtually impossible to define due to the extreme difficulty of stipulating what would count as an acceptable and what as an unacceptable sense, part, aspect, or element of difference. For example, Aquinas distinguishes between the doctrine that God is the form of all things (‘formal pantheism’) and the doctrine that God is the matter of all things (‘material pantheism’) (Moran 1989, 86). Does either of these count as pantheism ‘proper’, or must both obtain at the same time? Again, while some pantheists conceive of deity in mereological terms as the collection of things which make up the universe, many others have found this approach inadequate, maintaining that in some important sense ‘the whole is greater than the sum of its parts.’ The finite things that we encounter around us and are happy enough to describe as parts of nature we feel less happy to think of as parts of God. Such theorists may also reject the charge that their way of thinking is panentheistic, maintaining that the proper lesson to draw is not one of the transcendence of the holistic view but rather one concerning the degree of unreality or abstraction involved in any distributed view. In short, does any admission of difference between the world as common-sense experiences it and the divine cosmos as pantheism understands it amount to a concession either that there are aspects of experience which fall outside deity or aspects of deity which fall outside experience? If so, then the class of ‘true pantheists’ threatens to become null. In the end, rather than attempt to draw sharp but artificial and contentious lines it seems more fruitful to maintain that the boundaries of demarcation between immanence, pantheism, and panentheism are vague and porous.