Mortimer J. Adler : biography
In other words, the universe as we know it today is not the only universe that can ever exist in time. How do we know that the present cosmos is only a possible universe (one of many possibilities that might exist), and not a necessary universe (the only one that can ever exist)? We can infer it from the fact that the order and disorder, the arrangement and disarray, of the present cosmos might have been otherwise. That it might have been different from what it is. There is no compelling reason to think that the natural laws which govern the present cosmos are the only possible natural laws. The cosmos as we know it manifests chance and random happenings, as well as lawful behavior. Even the electrons and protons, which are thought to be imperishable once they exist as the building blocks of the present cosmos, might not be the building blocks for a different cosmos.
The next step in the argument is the crucial one. It consists in saying that whatever might have been otherwise in shape or structure is something that also might not exist at all. That which cannot be otherwise also cannot not exist; and conversely, what necessarily exists can not be otherwise than it is. Therefore, a cosmos which can be otherwise is one that also can not be; and conversely, a cosmos that is capable of not existing at all is one that can be otherwise than it now is.
Applying this insight to the fact that the existing cosmos is merely one of a plurality of possible universes, we come to the conclusion that the cosmos, radically contingent in existence, would not exist at all were its existence not caused. A merely possible cosmos cannot be an uncaused cosmos. A cosmos that is radically contingent in existence, and needs a cause of that existence, needs a supernatural cause, one that exists and acts to exnihilate this merely possible cosmos, thus preventing the realization of what is always possible for merely a possible cosmos, namely, its absolute non-existence or reduction to nothingness.
Adler finishes by pointing out that the conclusion reached conforms to Ockham’s rule (the rule which states that we are justified in positing or asserting the real existence of unobserved or unobservable entities if-and only-if their real existence is indispensable for the explanation of observable phenomena) because we have found it necessary to posit the existence of God, the Supreme Being, in order to explain what needs to be explained-the actual existence here and now of a merely possible cosmos. The argument also appeals to the principle of sufficient reason.
Adler stressed that even with this conclusion, God’s existence cannot be proven or demonstrated, but only established as true beyond a reasonable doubt. However, in a recent re-review of the argument, John Cramer concluded that recent developments in cosmology appear to converge with and support Adler’s argument, and that in light of such theories as the multiverse, the argument is no worse for the wear and may, indeed, now be judged somewhat more probable than it was originally.John Cramer. . Perspectives on Science and Christian Faith, March 1995, pp. 32–42.
Religion in modern times
Adler believed that, if theology and religion are living things, there is nothing intrinsically wrong about efforts to modernize them. They must be open to change and growth like everything else. Further, there is no reason to be surprised when discussions such as those about the "death of God" – a concept drawn from Nietzsche – stir popular excitement as they did in the recent past, and could do so again today. According to Adler, of all the great ideas, the idea of God has always been and continues to be the one that evokes the greatest concern among the widest group of men and women. However, he was opposed to the idea of converting atheism into a new form of religion or theology, and cited many "new theologians" such as William Hamilton, Paul Van Buren, Thomas Altizer and Gabriel Vahanian, who promoted this error:
Adler saw such movements as obvious and disingenuous attempts to convert atheism and secularism into new forms of religion, rather than calling them by their right names:
