Actions can have qualities and be subjects, like when we say "walking is good for health". Would Aristotle say that actions are substances?

  • 1
    No; see Aristotle's Categories Commented Mar 14 at 14:31
  • Indeed at first glance it seems to fit syntactically, however, your 'good for health' quality might not be proper enough to be a property of your intended subject 'walking' since apparently walking itself is usually deemed neutral (not subject bearer of either good or health) and even may be dangerous in some situations... Commented Mar 14 at 14:47
  • No, actions are relatives because they are predicable of the actor. For Aristotle, primary substances are individual objects that are not predicable of anything else (like Socrates), and secondary substances are kinds of individuals (like man), see SEP, Substance. Purely linguistic nominalization of verbs into gerunds like "walking" does not equal metaphysical transformation of relatives into substances.
    – Conifold
    Commented Mar 15 at 4:23

2 Answers 2


In cases like the OP’s question and if oneself is not quite sure whether the Aristotelian concept applies not only to objects but also to actions, it can be a good strategy to ask ChatGPT.

I asked ChatGPT:

According to Aristotle are actions substances?

Its answer is „No“.

Even more, ChatGPT presents a clear and correct argument, convincing everyone who is a bit familiar with the Aristotelian concepts. The key point of its answer reads:

"Actions, on the other hand, are the ways in which substances express their potentialities or capacities." (ChatGPT)

I don't think that a human person could have provided a better answer - at least concerning clarity ChatGPT outrivals the Delphic oracle by orders of magnitude ...

  • 1
    Perfect! Why loosing time to read books when it is enough to "ask ChatGPT"? Commented Mar 14 at 14:34
  • 1
    @MauroALLEGRANZA I assume we agree, that answers from ChatGPT only help those who are a bit familiar with the background of the concepts. Otherwise we could also learn by heart the encyclopedia and then act according to Searle's Chinese Room.
    – Jo Wehler
    Commented Mar 14 at 14:40
  • +1 "No; see Aristotle's Categories – Mauro ALLEGRANZA" That seems pretty darned clear to me. ; )
    – J D
    Commented Mar 14 at 23:48

There is no reason why an action can't be a substance. Aristotle also accepts incorporeal substances. However, the answer has to be given differently in the context of logic and metaphysics.

Aristotelian logic divides concepts into ten categories (discussed in the eponymous book), one of which is substance, which is referred to in its own right, the others being things predicated of another substance. We could use the concept "walking" in one of three ways:

(1) Going for a walk today was good for my health.
(2) Walking is good for health.
(3) I'm walking.

In sentence (1), "a walk" is an instance of walking. This is what Aristotle calls a primary substance, comparable to an individual human (as opposed to abstract walking, comparable to the human species).

In sentence (2), walking is certainly referring to a substance: the abstract notion of walking (if you doubt this, consider: what is being predicated of what?). According to Aristotle (Categories 5) an individual act of walking is more truly substantial than the abstract notion of walking, the reason being that it's possible to state "a walk is walking" but not "walking is a walk" (i.e. the general can always be predicated of the particular, but the opposite is not true). However, as demonstrated in this sentence, it's also possible to use abstract walking as a substance.

In sentence (3), "walking" is an act being predicated of the person who is doing the act. The concept of walking is not being referred to in this sentence as a substance; this sentence is referring to an act that "I" (a human) am doing but is extraneous (accidental) to who I am (which is a human).

But in metaphysics (the study of being, which is touched on only briefly in Aristotle's logical works, e.g. On Interpretation 3), we recognize that each of the three times we referred to walking, whether essentially or accidentally, we were talking about the same thing, something that really exists and can be discussed, i.e. we were signifying a substance. So the fact that "walking" in "I'm walking" is predicated accidentally of "me" doesn't change the fact that it's referring to the same thing as the abstract concept of "walking" which can be discussed in its own right.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .