Why is there anything at all?
Thomas Aquinas's argument from essence and existence.
Why is there something rather than nothing? Here we go through the answer Thomas Aquinas gave in his short work De ente et essentia (On Being and Essence). The argument does not rest on physics or on the world having a beginning, which is why it holds up well in conversation.
Read the argument in short first. Then walk through it step by step. At each step you can pick the most common objection and see how to answer it. If a concept is new to you, open the explanations below the argument.
The argument in short
The argument in five sentences, to learn by heart.
- What a thing is does not tell you that it exists.
- So everything around us has received its existence from something else. Nothing can give itself existence.
- A chain in which everything only has borrowed existence does not explain why anything exists, however long it is.
- So there is something that has not received its existence but is its own being. There can only be one such thing.
- This is what we call God.
Concepts you needEssence and existence · Act and potency · Cause
Essence and existence essentia, esseEssence is what a thing is. Existence, or being, is that it is. In everything created the two are distinct: existence is not part of what the thing is.
Example
You know what a rose is without knowing whether there is a rose on the table. To know that, you have to look.
In Thomas
Thomas discusses the distinction in De ente et essentia, ch. 3 (ch. 4 in some editions). In Summa theologiae I q.3 a.4 he shows that only in God are essence and being the same.
Act and potency actus, potentiaPotency is the capacity to become or receive something. Act is its actually being so. What receives something is in potency to it, and what is received is its act.
Example
A seed is a tree in potency, a grown tree is a tree in act. Cold water is hot in potency, until someone heats it.
In Thomas
Thomas applies the concepts to existence: what receives its existence is related to it as potency to act (De ente et essentia, ch. 3). In God there is no potency, and so his essence and his being are one (Summa theologiae I q.3 a.4).
Cause causa fiendi, causa essendiA cause is what something depends on. Thomas distinguishes the cause of a thing coming to be from the cause of its being. He also distinguishes chains whose links merely follow one another from chains where each link acts right now through the one before.
Example
A builder is the cause of a house coming to be, but the house still stands when he goes home. The sun is the cause of the light in the air, and the light vanishes the moment the sun stops shining.
In Thomas
The builder and the sun are Thomas's own examples, in Summa theologiae I q.104 a.1. He writes about the two kinds of chain in I q.46 a.2, reply 7: a stone moved by a stick, moved by a hand, compared with generations where one man is begotten by another.
Step by step
or tap a box in the map to see the texts behind it.
Test yourself
Think of your answer first. Nothing is saved.
What is the difference between essence and existence?
Essence is what a thing is. Existence is that it is. You can know the one without knowing the other.
Why can nothing give itself existence?
It would have to exist before it existed, in order to give itself existence.
How do you answer someone who says the universe could always have existed?
The argument does not rest on a beginning. Even what has always existed needs to receive its existence at every moment, as light in the air needs the sun.
Why can't the chain of borrowed existence go back forever?
Because each link acts right now through the one before, like the stone, the stick and the hand. Without something that has existence itself, there is nothing to lend, however long the chain.
What do you say when someone asks who created God?
The argument only says that what has received its existence needs a cause. God is his own being and has not received his existence from anyone.