The Self-Sufficient God

Why is there something rather than nothing? This is a classic philosophical question, and if you find it interesting, perhaps this is because you already have an intuition that the things around you are “contingent,” i.e., they don’t need to exist. And if you believe that they are contingent, this can be the first step in an argument for the existence of God known as the “Third Way” of Thomas Aquinas.

Why is there something rather than nothing? This is a classic philosophical question. Share on X

This paper will introduce the Third Way, which consists of the following four stages:

1. Some things are contingent.
2. If so, there must be a necessary being.
3. If so, there must be a self-sufficient necessary being.
4. This self-sufficient necessary being is what we call “God.”

We will now consider each stage in succession.

STAGE 1: Some Things Are Contingent

When we say that something is “contingent,” we mean that it is able to either exist or not exist. When we say that something is “necessary,” we mean that it must exist, and cannot not exist.

How do we know that some things are contingent? Perhaps we can see this through intuition. For example, as you look at a lamp, and you think about it, you might come to see that it doesn’t need to exist. Indeed, our interest in the question, “Why is there something rather than nothing?”, is a sign of our intuition that the things around us don’t need to exist.

Moreover, as Aquinas points out, the contingency of things can be seen from the fact that they are generated and corrupted, e.g., paper will cease to exist as paper if it burns. Such things are clearly able to either exist or not exist.

Moreover, any objector who denies that “some things are contingent” must embrace the alternative that “everything is necessary.” If so, the objector has already accepted stage 2 of the argument, namely, that there is at least one necessary being. So, a denial of stage 1 does not undermine Aquinas’s main argument, rather, it only accelerates us to the end of stage 2.

However, for those who do accept stage 1, let us now proceed to stage 2.

STAGE 2: If so, there must be a Necessary Being

Aquinas now argues for the existence of at least one necessary being. He has two arguments for this.

His first argument, given in his Summa Contra Gentiles (b.1, c.13, no.5), can be loosely interpreted as follows. Given that contingent things can either exist or not exist, something must play the role of deciding (or determining) whether or not they exist. But nothing can decide for itself whether or not it exists. Therefore, contingent things cannot decide for themselves whether or not they exist; rather, they need something else, i.e., a necessary being, to decide (or determine) whether or not they exist. So, there must be a necessary being.

Aquinas’s second argument, given in his Summa Theologiae (I, 2, 3), is as follows. If all things are contingent, then there was a time when nothing existed. But, if there was a time when nothing existed, then nothing would exist now, since nothing comes from nothing. However, it is clearly false that nothing exists now. Therefore, not all things are contingent; and there is at least one necessary being.

Why does Aquinas say (in the above argument) that if all things are contingent, there was a time when nothing existed? Perhaps he’s thinking of something like this. Let’s imagine that there is only one thing in existence: a contingent thing. So, it is intrinsically able to either exist or not exist. Therefore, as time passes, it will sometimes continue to exist, and it will sometimes cease to exist (never to return). Likewise, let us now imagine that there are many things in existence, and all of them are contingent. Thus, as time passes, everything will sometimes continue to exist, and everything will sometimes cease to exist (never to return). Therefore, if everything is contingent, there must have been a time in the past when nothing existed, and so nothing would exist now, which is clearly false. Therefore, not all things are contingent.

If everything is contingent, there must have been a time in the past when nothing existed, and so nothing would exist now, which is clearly false. Therefore, not all things are contingent. Share on X

At this point, an objector may respond by proposing that the cessation of contingent things need not result in nothing; rather it may result in the coming to be of new contingent things. For example, perhaps contingent things are composed of indestructible atoms which configure themselves into new contingent things. Or perhaps there is a permanent conservation law ensuring that the cessation of one contingent thing results in the generation of another contingent thing. However, Aquinas could respond to this objection by pointing out that the objector is thinking of the “indestructible atoms” and/or “permanent conservation law” not as contingent, but as necessary. If the atoms or laws were truly contingent, they could cease to exist. But since they are postulated as “permanent” and “indestructible,” they must be either 1) necessary or 2) sustained by something necessary. Thus, the objector is already granting the truth of step two: there must be at least one necessary being.

In short, if you’ve ever wondered why contingent things (like lamps) don’t simply pop out of existence before your eyes, Aquinas would say that this is because some necessary reality is holding them in existence through time. Moreover, if Aquinas were asked the question, “why is there something rather than nothing,” he might respond with this: “because something exists necessarily.”

STAGE 3: If so, there must be a Self-Sufficient Necessary Being

Aquinas goes on to distinguish between two hypothetical kinds of necessary being: 1) dependent and 2) self-sufficient. A dependent necessary being draws its existence from another (i.e., a sustaining cause), whereas a self-sufficient necessary being has existence through itself.

So, either 1) there is an infinite chain of dependent necessary beings, each one depending on the next or 2) there is at least one self-sufficient necessary being which does not depend on anything else.

Either 1) there is an infinite chain of dependent necessary beings, each one depending on the next or 2) there is at least one self-sufficient necessary being which does not depend on anything else. Share on X

Aquinas then says that there cannot be an infinite chain of dependent beings. His basic argument seems to be as follows. Suppose that A depends on B which depends on C. In that case, B is a “middle,” i.e., a being which both sustains another (i.e., A) and is sustained by another (i.e., C). Moreover, if there is a chain of dependent beings (e.g., A depends on B which depends on C which depends on D which depends on E), then all the middles together form one long middle (e.g., B-C-D). Now suppose that there is an infinite series of dependent beings, each one depending on the next. In that case, there is infinitely long middle with nothing before it. But there cannot be a middle with nothing before it, since that contradicts the definition of a middle (i.e., that which sustains another and is sustained by another). Thus, there cannot be an infinite series of dependent beings. So, there must be at least one self-sufficient being.

Perhaps a similar argument can be formulated like this. Some attributes are convertible from parts to whole, whereas others are not. For example, if every part of a house is blue, then the whole house is blue. So, “being blue” is convertible from parts to whole. However, if every part of the house is small, it doesn’t necessarily follow that the whole house is small. So, “being small” is not convertible from parts to whole.

Moreover, it seems that “being dependent” is convertible from parts to whole. For example, imagine a stick suspended horizontally in the air such that every part of the stick is exactly 2 ft above the ground. Moreover, suppose that the suspension of every part of the stick is dependent. For example, the suspension of this part depends on the suspension of another part which depends on the suspension of another part, etc. But in this case, it seems that the suspension of the whole stick must also be dependent. For, if there is nothing outside the stick holding it up, it will simply fall to the ground; and this would be true even if the stick is infinitely long or configured in a loop. In short, if all the suspensions of all the parts are dependent, then the suspension of the whole is also dependent. From this, it seems that “being dependent” is convertible from parts to whole.

Therefore, if we consider the collection of all dependent necessary beings (whether it’s finite or infinite), this collection as a whole must also be dependent. But it can only be dependent on a self-sufficient necessary being. Thus, there must be a self-sufficient necessary being.

STAGE 4: This Self-Sufficient Necessary Being is what we call “God.”

Although Aquinas is quick to say that a non-dependent necessary being is “what we call God,” some readers might demand more. For example, someone might think that the universe consists of many indestructible particles, each of which is its own “self-sustaining necessary being,” and none of which deserves the name “God.” Thus, in order to show that a non-dependent necessary being truly deserves the name “God,” we must consider Aquinas’s later arguments for why this being has the attributes we normally associate with “God.” We don’t have the space to consider all these arguments in detail here, but we can skim through a few.

First, a self-sufficient necessary being must be entirely self-sufficient. For example, it cannot be composed of 1) a self-sufficient aspect and 2) a dependent aspect; otherwise, the real “self-sufficient necessary being” would be the self-sufficient aspect alone, not the two aspects together.

Moreover, a self-sufficient necessary being cannot be composed of parts. For, if it were composed of parts, then either 1) the parts are dependent on the whole or 2) the whole is dependent on the parts. But both options are contrary to the previously established principle that the self-sufficient necessary being is entirely self-sufficient, without any dependent aspects. Therefore, a self-sufficient necessary being cannot be composed of parts.

Moreover, there can only be one self-sufficient necessary being. First, the self-sufficient necessary being is the first principle of all else; and, as Aquinas argues, the harmony of the universe points to one first principle, not many first principles. Second, if there were two self-sufficient necessary beings, they would be similar to each other with respect to “self-sufficient necessary existence.” But they cannot be similar to each other in every way, otherwise, they would be the same being. Thus, at least one must be composed of two parts 1) that whereby it is similar to the other, and 2) that whereby it is distinct from the other. But this is contrary to the previously established principle that a self-sufficient necessary being cannot be composed of parts. Thus, there can only be one self-sufficient necessary being.

Hence, the universe cannot be composed of many particle-like self-sufficient necessary beings. Rather, there is only one self-sufficient necessary being which causally sustains all other beings (including the whole visible universe) in existence.

There is only one self-sufficient necessary being which causally sustains all other beings (including the whole visible universe) in existence. Share on X

Moreover, the effect cannot be greater than the cause. Thus, the self-sufficient necessary being must be at least as perfect as its effects. But its effects include intelligence, goodness, and power (all of which can be found in the visible universe). Therefore, the self-sufficient necessary being must be intelligent, good, and powerful. Moreover, since the self-sufficient necessary being is not the cause of “non-being,” it is therefore not the cause of evil (which is a privation, not a being).

Of course, there are many other divine attributes which we haven’t yet touched on (e.g., infinity, pure actuality, omnibenevolence, omnipotence, etc.). But this will suffice as an introduction to the argument of the Third Way, both 1) that there is a self-sufficient necessary being and 2) that it has many of the attributes needed to deserve the name “God.”

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