A Philosophical Happy Hour on the distinction of potentiality and possibility in both being and knowing.
When we speak about what “could be”, we often unthinkingly use the words “possible” and “potential” as though they were interchangeable. Yet beneath this ordinary use lies a subtle but nevertheless important distinction: a distinction that reaches into the depths of how we (mis)understand change, existence, and even ourselves. Consider, for instance, the difference between, first, the imaginative act which renders a fictitious universe—a universe with entirely new laws of nature—and, second, the concrete capacity of an acorn to become a tree. Both, in some sense, concern what “is not yet”. But one concerns only what the mind can conceive without contradiction; the other concerns what actually might come to be, given the right conditions.
Philosophers in the Aristotelian and especially Scholastic traditions have emphasized that reality itself contains principles of becoming—what they called “potency” or “potentiality”. But not everything conceivable carries this kernel for real existence. Some things are “possible” only because our minds can imagine them; others are “potential” because the world itself bears within it the power to bring them forth.
In the Aristotelian-Scholastic tradition of inquiry, countless volumes have been dedicated to these deep and difficult metaphysical topics. Observation of both natural beings in their physical concrete reality and of the operations of the human mind have resulted in many distinctions. One might hear of “logical potency”, “objective potency”, “subjective potency”, “material potency”, “logical possibility”, “real possibility”, and so on—of the oppositions between “necessary” and “impossible” or “possible”, etc. The abstractness of the concepts makes their understanding difficult.
As such, exploring the meaning of these terms draws us into the heart of metaphysics. It challenges us to consider not only what is and what could be, but the very principles by which reality unfolds from possibility into actuality. Though they are abstract, however, these concepts are operative in all our thinking—and gaining some clarity benefits us all.
Questions We Can Ask
To help guide our conversation here, allow us to pose these questions:
- When we use the phrases “could be” and “what is able to be”, are we signifying different objects? What comes to mind with these phrases—or with the terms “possible” and “potential”?
- How do the conditions of what is determine or affect the conditions for what could be—how do time, circumstance, agency, instruments, etc., affect the possible and the potential?
- To what is “possible” opposed? To what is (the “actual”), to what must be (the “necessary”), to what cannot be (the “impossible”)? How are these oppositions alike, how different? What does this tell us about the nature of the possible and impossible?
- Does “possibility” have a special primacy in our acts of knowledge?
- What does it mean to say that “potentiality” can be defined or understood only in explicit reference to some actuality?
And to help contextualize our conversation, let us consider these handful of passages from Aristotle’s Metaphysics and Thomas Aquinas’ Commentary on it:
…it is necessary to know that the word “possible’ is said in two ways. In the one way, it is divided against what is necessary; as when we say those things are possible to which it belongs to be or not to be. And taking “possible” in this sense, it is not said in this way in this place [i.e., in Aristotle’s Metaphysics 9.4, and specifically where Aristotle considers the relations of antecedent and consequent]. For nothing prohibits the antecedent contingently from being or not being, even if the consequent be necessary; as is clear in this conditional: “If Socrates laughs, then he is human.”[1]
The other way in which “possible” is said is according to what is common both to those things which are necessary and to those things to which it belongs to be and not to be, insofar as the possible is divided against the impossible. And thus it is that the Philosopher uses it here; saying of the possible, that it is necessary for the consequent to be possible if the antecedent is possible.[2]
And first Aristotle says what it means to be in potency: namely that which is said to be in potency, is that which if it is posited to be in act, nothing impossible follows.[3]
…[the various senses of potency] are meant in reference to one primary kind of potency, which is a source of change in some other thing or in the same thing as other. For one kind is a power of being acted upon, which is a source in the acted-upon thing itself of passive change by the action of something else or of itself as other; another is an active condition of being unaffected for the worse or for destruction by the action of a source of change; either some other thing or itself as other. For the articulation of the primary sort of potency is present in the definitions of all these.[4]
You Can Participate
Well—let us just say that participation is at least possible for you! Whether or not you have the potential—this we cannot guarantee. But please, if you are free, join in for what should be a lively and enlightening discussion of metaphysics.
We will meet this Wednesday (24 September 2025, from 5:45-7:15+ pm ET) to see what we can figure out together.
[1] 1270/71: In meta, lib.9, lec.3, n.1811.
[2] 1270/71: In meta, lib.9, lec.3, n.1812.
[3] 1270/71: In meta, lib.9, lec.3, n.1804.
[4] i.348-30bc: Meta. 1046a 10–15.