Does Modal Realism Explain Why Anything At All Exists?
Perhaps the biggest question in all of philosophy is ‘why is there anything at all’?
What if the answer to this question is just that something necessarily has to exist because a state of ‘nothing at all’ is impossible. This is called a necessitarian response to the fundamental question and in this article, I’ll investigate a necessitarian argument called modal realism that may explain what some consider the most important question humanity has ever asked.
What follows is a very brief exploration of modal realism and possible world theories. I recommend you learn more about them if you’re interested by reading the book On the Plurality of Worlds by David Lewis.
What is Modal Realism?
David Lewis, regarded by some as one of the most important philosophers of the 20th century, believes there’s a logical explanation to the question and his theory of modal realism proves that it’s necessary that something must exist.
Modal Realism is a philosophy that states that literally all possible worlds exist and they are the same kind of thing as the actual world (they are made of concrete objects, not abstract ones).
So, let me explain exactly what that means.
Take the statement ‘the dinosaurs may still be around if the asteroid missed Earth’. It sounds like a true logical statement to make, but what exactly makes it true? It can’t be proven empirically since dinosaurs no longer exist nor figured out mentally per se by analyzing concepts like 1+1=2.
Or take the statement ‘We’d be speaking German if Hitler won WWII’. It sounds like a perfectly rational thing to say, but it’s about what the world isn’t. So what makes it seem logically true?
Statements such as these are called modal statements. The term modality is concerned with possibility, necessity, impossibility, and includes what could be the case and what must be the case.
Some philosophers including Lewis believe modal statements are true if the statement can exist in a ‘possible world’.
What’s a possible world?
Well, what Lewis calls ‘the actual world”, is the collection of everything there is in our universe or multiverse that we live in. A possible world is a universal multiverse where something different happened from the actual world we live in.
To say the dinosaurs may still be around if the asteroid missed earth can be thought of as in some possible world, the asteroid missed Earth and dinosaurs still exist there.
When Lewis says a possible world, he means literally that. Another world that really exists outside of our own. These are real things.
Specifically, a possible world is a maximal mereological sum of spatiotemporally related things. Mereology concerns the study of parts and the wholes they form. Possible worlds are like objects with everything in the object connected in some way but fully separate from all the other objects.
The underlying reason for this is that he believes that this is what the actual world is. In other words, possible worlds are just “different ways things could have been”, so they must be significantly similar to the actual world, with variations.
Why Would He Believe in Something so Radical?
Ok, so why would he believe something so radical like that, in infinite possible worlds? This sounds very unlike the very empiricist way of thinking of how many scientists and philosophers approach issues today, right?
Lewis believes the best theories are not necessarily simple, but explanatory. We should believe in the existence of whatever our best theories quantify even if it involves believing in an infinite number of other possible worlds. The theory may sound complex, but there’s a finite number of types of things that can exist, specifically concrete things like objects, humans, apples, trees, etc., since possible worlds are variations of the actual world.
How Does This Answer the Fundamental Question?
But, how does this answer the ‘why does anything at all exist’ question?
Well according to Lewis’s theory, there can be no world that is in a fully empty universe and does not have concrete objects in it. Specifically, he writes that since mereology does not permit ‘empty sums’, there can be no empty world. Because modal realism doesn’t allow for a non-concrete world, that makes it a necessary fact that there is something.
According to modal logic;
- A proposition X is necessarily true if X is true in all possible worlds.
- The proposition something exists is true in every possible world because a world without a spatiotemporal concrete entity wouldn’t be a world.
- If the proposition something exists is true, then that means a world with nothing in it is necessarily false.
Lewis isn’t the only one to employ the idea of possible worlds to analyze logical necessity as truth. There are other similar theories. It’s important to note, however, these possible world theories don’t outright state that the concept of nothing is illogical, it’s just that if we embrace a possible worlds theory then a state of ‘nothing existing’ can’t happen.
Therefore, we’ve solved the fundamental question ‘why does anything at all exist’.
Now we can dive deeper into modal realism and other possible world theories, but if it’s possible to prove the idea of nothing existing or a world with nothing as a coherent logical possibility, then all these types of necessitarian theories will fail.
So, does anyone have an argument that can?
The Subtraction Argument
It just turns out there is a philosopher who presented an argument that shows that there could be a possible world where nothing exists, specifically nothing concrete. His name is Thomas Baldwin, a professor at the University of York, and his argument is based on the idea that it’s always possible to subtract a concrete object for a given possible world and thus find another possible world accessible from the first world which has exactly one less concrete object in it.
He starts with these premises:
- There might be a world with a finite domain of concrete objects
- These concrete objects are, each of them, things which might not exist
- The non-existence of any one of these things does not necessitate the existence of any other such thing.
Then he shows the procedure for subtracting objects from worlds until we’re left with a world where we only have one concrete object left to subtract. Once we do that we arrive at the empty world nullifying this type of necessitarian theory.
Lewis could argue back that one could claim that we can get down to a world with exactly one concrete object, but if we remove it, we are no longer talking about a possible situation.
But, if the question of whether the empty world is possible comes down to the question of whether we can think of a possibility that is not a possibility of or for anything, then it seems that the issue is decided.
As long as we think of existence as a contingent matter, we can subtract as many items as we like from the actual world without violating any conditions on possibility, thus disproving these types of theories.
But, What About ‘Abstract’ Objects and Concepts?
But, hold on one second. What about abstract objects? I’m talking about intangible things like spacetime, math, logic, or even ‘possibility’ itself. The concept that ‘something possible’ could happen.
We may be able to conceive of one level of nothingness with nothing concrete in it, but what about another level where there’s no abstract objects, and no concepts, including the possibility that there’s no possibility for anything to exist or happen.
Would this world with truly nothing in it, be a world at all since the concept ‘world’ and ‘nothing’ attempts to give it some sort of domain. Is this type of pure nothing something illogical or a paradox?
I’ll explore this idea plus some more theories that may get us around this issue in a future article.
But, let me know what you think of very short introduction, mind-bending into modal realism and the fundamental question below.
Again, if this sort of thing interests you check out the full argument from David Lewis for yourself in his book Possible Worlds.
Plus, make sure to subscribe for more articles on existence from me below.
The Rest of the Articles in This Series Including the Best Answer:
Part 1. Questioning the Question and Types of Responses:
https://thinkingdeeply.medium.com/the-types-of-answers-to-why-is-there-something-rather-than-nothing-7360f54253f
Part 2. The Probabilistic Argument for Existence (Nozak & Van Inwagen): https://thinkingdeeply.medium.com/the-probabilistic-argument-for-why-anything-exists-at-all-examined-van-inwagen-nozick-6fd7f209d11d
Part 3. Modal Realism and Probable Worlds Argument (David Lewis): https://medium.com/curious/does-modal-realism-explain-why-anything-at-all-exists-db3c43a45df9
Part 4. Necessitarian Theistic Argument (Leibniz & Craig) https://thinkingdeeply.medium.com/does-god-explain-why-there-is-something-rather-than-nothing-1ba79fd90639
Part 5. The Brute Fact Argument (Hume & Russell) https://thinkingdeeply.medium.com/does-the-brute-fact-argument-explain-why-is-there-something-rather-than-nothing-189eb0289aa9
Part 6. Axiological Arguments (Leslie, Rescher, Tegmark) https://thinkingdeeply.medium.com/do-abstract-objects-explain-why-anything-exists-at-all-axiological-arguments-for-existence-fc9b194a3af9
Part 7. Is the Question Meaningless? (Wittgenstein, Edwards, Positivism, Smith) https://thinkingdeeply.medium.com/is-the-question-why-is-there-anything-at-all-actually-meaningless-1c8f2ce96703
Part 8. The Best Response: https://thinkingdeeply.medium.com/why-is-there-something-rather-than-nothing-the-best-answer-e568f468459a
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References:
https://www.wiley.com/en-us/On+the+Plurality+of+Worlds-p-9780631224266
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