Book Review: Necessary Existence
Everything that exists that we know of is contingent. Something being contingent means it exists because of something else existing that caused it to exist, or at least provided the necessary conditions, for it’s existence. Contingent beings thus depend in their very existence on other things that exist. They could have thus failed to exist to begin with if not for the existence of other things. Trees, rocks, planets, galaxies, and everything else in the universe apparently, all exist contingent upon other things. The entire collection of everything we know of is an interconnected, interdependent web of contingently existing things existing contingently on other contingent things. All of which could have thus failed to exist to begin with. So why does anything exist at all if everything could have failed to exist to begin with? ?
This brings up the basic question in metaphysics of whether everything that exists exists contingently, or can or does something exist that is not contingent upon anything else for its existence? Philosophers call this hypothetical non-contingent being a necessary being. What would that be? First of all, as stated, it would have to be something that exists not because of anything else. It would therefore exist of itself, that is, as a result of what it is, its own nature (this self-existence is called aseity). It would be “necessary” in its existence as it could not not exist. Since it’s existence is not contingent on anything else, it could not go out of existence under any internal or external circumstances. As the authors state in the book, a necessary being would exist “no matter what.” In this way it would have necessary existence as opposed to contingent existence.
What could be a non-contingent or necessary being? Philosophers have proposed two main possibilities: abstract objects such as propositions and mathematical entities (numbers, sets) and of course, God, the latter seen as the ultimate, uncaused cause of everything else, thus the necessary Being that is the source or ground of all contingent being. Abstract entities are generally seen as being unable to cause anything else to exist given their abstract nature, and are thus generally not thought to be the ultimate source of contingent being, even if they do exist and in a necessary as opposed to contingent manner.
The authors, Alexander Pruss and Joshua Rasmussen are both theists and in the Introduction (chapter one) they say they are primarily concerned with concrete as apposed to abstract necessary being, that is, ones that are “capable of causation” (p. 2). They say this type of necessary being is not synonymous with God. There hypothetically could be other concrete necessary beings in existence. They say about their project in this book:
Our question, then, is this: is there anything that (i) possibly causes something (is concrete in our sense) and (ii) exists no matter what?
In asking if there is anything that possibly causes something, they are indicating theirs is a modal approach dealing with possibility and necessity (more on that below). “In keeping with tradition” they call whatever satisfies both requirements a concrete necessary being.
The question of necessary existence, they say, has relevance to Ontology, Theology and Cosmology (p. 2). The relevance to theology is obvious, as God is traditionally and almost universally viewed as a necessary, not a contingent, Being. Its relevance to the other two is due to the fact, in part, that some physicists are looking for a “theory of everything” or of what they think is the whole of reality, even if that consists only of this universe. They write about this project of physicists to find a theory of everything:
The search for an ultimate explanation invites a question: what kind of an explanation can be ultimate? Can contingent reality alone constitute an ultimate explanation? (p. 3)
They mention Lawrence Krauss’s claim that the universe came from “nothing,” which as I have claimed is an equivocation of its normal meaning and philosophical use. They say Krauss’s claim
… inspires curiosity: his state of ‘nothing’ includes laws and conditions, and one may like to know what could explain their existence. Might other laws and conditions have obtained instead? If so, what accounts for the existence of these particular starting conditions? Why did they obtain? One theory is that there is no answer–no deeper explanation. But consider the alternative: a necessary concrete reality lies at the ultimate explanatory foundation of our universe. That’s an importantly different kind of answer relevant to cosmogony. (p. 3)
If one or more concrete necessary entities lie at the foundation of contingent reality, either physics can describe it in physical terms or not. If not, then, “even the most complete physical theory” physics can come up with would miss out on the most fundamental component(s) of reality. A ‘theory of everything’ would be impossible for science, even in principle (p. 3).
All that background just brings us up through page 3.
Chapter two, Metaphysical Possibility and Necessity, provides a brief description of modal logic and modal approaches to possibility and necessity. Modal logic is the approach this book uses in presenting arguments for the existence of at least one concrete necessary being. They use S4 and S5 axioms and approaches saying, “The modal system S5 is the main modal system in this book.” (p. 14) The most famous, or infamous if you prefer, example of the use of S5 in an argument for a necessary being that exists in all possible “worlds” is Alvin Plantinga’s modal ontological argument. The argument between premise one (It is possible that a maximally great being exists) and the conclusion (Therefore, a maximally great being exists) is an S5 based modal argument from possibility or possible worlds.
Chapters three through eight present the six major arguments in the book for a necessary concrete being using this approach. Each argument is presented as a separate chapter. Chapter nine examines what they believe are the major arguments against the existence of a necessary being that have been advanced. An appendix contains a plethora of other, apparently new arguments, for a necessary being without much comment. They say these are minimally plausible arguments that they believe are worthy of further exploration by philosophers.
Each chapter on the arguments typically presents the argument, sometimes offering a more modest or restricted version, discuss objections to them, and have a final assessment of the argument and it’s pros and cons.
The first argument (chapter three) is an “up-to-date version” of the traditional Leibniz-style argument from contingency for a non-contingent, necessary being. They call their version the Argument From Contingent Existence or ACE. The more traditional Leibnizian-style cosmological argument is sound to me. It is the strongest argument to me for the existence of God, so it is appropriate that the authors start here. The “initial statement” (p. 34) of this argument is:
(1) For any particular contingent concrete things, there is an explanation of the fact that those things exist.
(2) Considering all the contingent concrete things that exist, if there is an explanation of the fact that those things exist, then there is a necessary concrete thing.
(3) Therefore, there is a necessary concrete thing.
That formulation distills contingency arguments into two premises that, if true, demonstrate that a concrete necessary thing must exist. The first premise is their explanatory principle or version of a Principle of Sufficient Reason (PSR). The second premise seems undeniable, so, as is usually the case with contingency arguments, it comes down to the truth or falsity of the explanatory principle. Since contingency arguments with an explanatory principle already have a history in philosophy going back at least to Leibniz and his PSR, they deal with the numerous objections to this type of argument that have been advanced: five by Hume, two by Kant and a recent one by Oppy and Leon.
Chapters 4 and 5 present two modal arguments from possible causes of contingent being. The first (chapter 4) is a Modal Argument from Beginnings (MAB). It argues for contingent being possibly having a cause of their beginning to exist. Since a cause of contingent being beginning to exist could not be contingent itself, it would have to be a necessary being. It strikes me as something of a modal version of a Kalam-style cosmological argument. The second argument (chapter 5) is a more modest causal argument from possible causes. They call it The Weak Argument from Beginnings (WAB). These two modal versions of cosmological arguments are interesting approaches and such modal approaches should spark interest and debate. Modal approaches are needed and helpful here.
Chapter six presents an argument from “modal uniformity.” I don’t know if this concept is original with the author(s) here, as it is new to me. They describe the concept this way:
Modal Uniformity: Normally, if a proposition p differs from a proposition q by a mere quantity, then p is possibly true iff q is possibly true.
They use the example of objects being collocated at the same place. If two of the same objects can be collocated, why not 3? 4? 276? The number seems irrelevant if you grant two objects can occupy the same space. Same with using size differences in a sequence of otherwise same objects. They admit all modal uniformity principles are “defeasable” so need to be examined on a case by case basis, but would still be useful to philosophers. Again, they use modal uniformity principles on arguments from contingent beings to argue for a necessary being. They apply it to their previous ACE and MAB arguments for potential added support.
Chapter 7, From Necessary Abstracta to Necessary Concreta is fairly straight forward. They argue that if, necessarily, abstract objects exist, then with a couple possibility premises regarding concrete contingent being and using S5, a concrete necessary being exists. Their main argument for this is interesting to me (see book for the details).
Chapter eight is “The Argument From Perfection.” This is a Godel like argument from “positive” properties or features. Necessary existence as well as “possibly causing something” is believed to be a “positive” property as they define positive here. This basically argues from the possibility to actuality of the existence of a being with such positive properties. This is the most abstract of the arguments for me and the most obscure one in the book. It reminded me of Plantinga’s discussion of what a “great making” property would be in a possible “maximally great” being.
Concluding Thoughts
The book is well written and is clear in it’s argumentation. The modal approaches here, especially the two cosmological arguments (chapters 4-5), are needed and important. They make the book worth reading for anyone, like myself, familiar with more traditional, non modal cosmological arguments. The other three main modal arguments are probably better suited and aimed at philosophers interested in philosophy of religion and those interested in modal arguments for a concrete, necessary being. The arguments in the Appendix are aimed at philosophers who may want to pursue the arguments for a necessary being further with various other, “minimally” plausible premises.
Overall, the book is a book by philosophers for philosophers, but chapters 3 to 5 may be of interest to anyone who is seriously interested in a new formulation of a contingency argument, and new modal based, cosmological arguments for the existence of a necessary being (e.g., God).
For a discussion with one of the authors, Joshua Rasmussen, of a modal cosmological argument from contingent being with an explanatory principle, see the video below. He also mentions their modal uniformity principle, etc. from this book.