LCA Point 5: The Necessary Object is God

This is our third post in a series on Leibniz’ Cosmological Argument. You can find the first post here and the second here. The full argument is:

(1)               Every contingent fact has an explanation.

(2)               There is a contingent fact that includes all other contingent facts.

(3)               Therefore, there is an explanation of this fact.

(4)               This explanation must involve a necessary object.

(5)               This necessary object is God.

Today we will be examining…

(5)               This necessary object is God.

This is much like the first point, in that it’s not obvious and requires some argumentation. First, let’s talk about what it means to be a necessary object. A necessary object is an object that explains its own existence. It does not “depend” on any other object to exist. Using the possible world terminology we introduced last post, a necessary object is an object that exists in every possible world. 

So what properties can we deduce about the necessary object? Well it’s clearly not material, as material objects depend on matter to exist and are contingent. In fact, it’s not composite at all, since composite objects depend on their components to exist. So the necessary object must be entirely simple.

Whatever necessarily exists must always exist, since the fact that it necessarily exists is true no matter what time period you are in. So the necessary object is everlasting.

The necessary object must be unchangeable. Suppose that the necessary object were to change. That change must either be caused by the necessary object itself, or something else. It cannot be caused by something else, because that would make the state of the necessary object contingent on that thing that caused it. So if it changes, it must cause that change itself. If something changes itself, either part of it changes another part, or the whole changes the whole. Since the object in question has no parts, the whole necessary object must change the whole necessary object. But if this were the case, it would have already been the thing it was going to change into. So it cannot change.

Now Leibniz presents an argument that the necessary object has understanding, a will, and power. He argues that it has understanding, as it can survey all possible worlds it can create. It has a will, as it selected one possible world. And it has power, as it actually created that world.

Is this argument reasonable? Consider first the understanding argument. Can the necessary object survey all possible worlds? A possible world is a world that could exist. If such a world contains any contingent objects, then the necessary object must exist. And if it doesn’t contain any contingent objects, and only the necessary object, then the necessary object must still exist.

Our necessary object explains all contingent objects. That means it must in some way contain information about those objects. And it contains information not only about contingent objects that exist, but also all possible contingent objects, since it would also explain them. And clearly it contains information of itself, since everything does. This kind of containing information is understanding.

Does it have a will? Of all the possible worlds, it chose one. Is simply choosing one possibility out of many having a will? Probably not, since my computer also does this and does not have a will. Instead, it seems more reasonable to say that having a will, or maybe a free will, is choosing an option apart from any outside compulsion. My computer chooses what it was programmed to choose, and so doesn’t have a will in this sense. But the necessary object is not compelled by anything external to it, and its choice comes entirely from within. So it seems it has a will.

And power? This one is more clear: it did in some sense create the world. It chose this possible world, and actualised it over other possible worlds. That is power.


Since the understanding, will, and power are directed towards all possibilities, they are infinite. The necessary being understands all possibilities, can will to create any of them, and has the power to carry out that will, whatever it may be.

And since choosing is to judge that the thing you choose is the best thing among the alternatives, and since the necessary object has full knowledge (knowledge of all possible worlds), it judges which is actually the best among infinitely many alternatives. This means that it is in a sense infinitely good.

Another argument can be made for a more general agency of the necessary object. As far as we understand explanations, there are three types: scientific, conceptual, and agential. The necessary object is clearly not a scientific explanation, since it cannot be material, due to simplicity. Further, science only explains things in terms of contingent things, or at least it has in every case we know of.

Nor is it a conceptual explanation. Among the contingent things we find substances, the stuff that other things are made from. Dualists will argue that the soul is a different kind of substance to matter, for example. Matter/energy is the substance that physical objects are made of. But the activity of a substance cannot be conceptually explained by the activity of something other than that substance. A conceptual explanation can tell us why things behave the way they do, in terms of what they are. But a conceptual explanation cannot give an account of why they are in the first place. So a conceptual explanation is insufficient for the big contingent fact.

So the only option remains is an agential explanation: an explanation in terms of some agent. So the necessary thing must be an agent in some sense.

We can also demonstrate uniqueness: every property the necessary object has must be a property it necessarily has, by a similar argument to the simplicity argument above. So if there are two necessary objects, they have the same properties. But two objects with identical properties are actually just one object. So there is only one necessary object.

At this point, we have proven that there exists a necessary object, which has infinite knowledge, infinite power, is infinitely good, is simple, eternal, unique, immutable etc. I know no name we could give this object other than “God”. And of course we have not yet arrived at Christianity. But I claim that after proving that this God exists, we may go looking for it in the world.

We find this: there exists a religious tradition spanning thousands of years who claim to worship something with all of these properties. They record centuries of interactions with this thing, who behaves exactly as we’d expect God to behave, including giving and fulfilling prophecy. And in the end we see the man Jesus who comes claiming to be God come in the flesh, who behaves as we’d expect God to behave, with a supremely good moral character, who fulfills prophecy given over the last few thousand years. I believe Him.

2 Replies to “LCA Point 5: The Necessary Object is God”

  1. I’m confused. How can something already be what it was going to change into? Why was it not one thing and then the other?

    1. It can’t be what it was going to change into. That’s my point, this is a reductio argument.

      It can’t be one thing and then another, because of the arguments I have just given.

      A fuller exploration of this can be found in chapter 4 of Aquinas’ Compendium of Theology.

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