Something about this post feels a little insane, but I've started so I'll finish...
traditionally in philosophy, anything that can be said to be is a being — Jamal
That is one I will need a citation for. — Wayfarer
τὰ ὄντα (ta onta) is what appears in ancient Greek philosophy. It's the plural form of the participle of the verb
to be and it means
things that are, or, to say exactly the same in a different way,
beings.
In English versions of Aristotle it has been translated in different ways, often avoiding
beings and opting instead for
things that are. The Loeb Classical Library notes that it avoids "beings" while at the same time acknowledging that it is a standard translation, that it has the same sense.
The plural neuter form of the participle, ta onta, occurs frequently to indicate things, things that are, beings (but we have tended to avoid the translation 'beings') — Early Greek Philosophy, Volume I: Introductory and Reference Materials
I don't know the reason for the general avoidance of "beings" in translations of Aristotle, but it could be the prevalence of the more modern use, which restricts it to sentient things (subjects of experience if you prefer). This is reasonable in a translation that aims to avoid confusing non-specialists, but it doesn't invalidate the use of "beings" generally in philosophy (to mean "things that are"). At least, it hasn't stopped scholars from continuing to use it.
The main point is that
τὰ ὄντα can interchangeably be translated as "things that are" or "beings". In philosophy they usually mean the same.
Aristotle deals with
τὰ ὄντα in his Categories and Metaphysics. In those works,
τὰ ὄντα is plainly not restricted to sentient individuals or subjects of experience (it can't be, because of what it means).
But to avoid translation issues I won't quote Aristotle directly. Following are quotations from a fairly small and random sample of articles in the search results for the term "beings" on the Stanford Encyclopedia of Philosophy, showing that it's commonly used in philosophy to mean
τὰ ὄντα or "things that are" or "things that can be said to be", especially when the subject under discussion is traditional metaphysics. Many of the quotations are from scholars of ancient and medieval philosophy.
The Categories begins with a strikingly general and exhaustive account of the things there are (ta onta)—beings. According to this account, beings can be divided into ten distinct categories. (Although Aristotle never says so, it is tempting to suppose that these categories are mutually exclusive and jointly exhaustive of the things there are.) They include substance, quality, quantity, and relation, among others. Of these categories of beings, it is the first, substance (ousia), to which Aristotle gives a privileged position. — SEP: Aristotle's Metaphysics
The correlatives form, therefore, a complex structure that is reproduced throughout the ladder and in each one of the beings, from God to a stone, to ontologically explain the continuity among all beings. In each one of them, the chain of the whole of creation is reproduced. — SEP: Ramon Llull
Aristotle announces that there is nonetheless a science of being qua being (Met. iv 4), first philosophy, which takes as its subject matter beings insofar as they are beings and thus considers all and only those features pertaining to beings as such—to beings, that is, not insofar as they are mathematical or physical or human beings, but insofar as they are beings, full stop. — SEP: Aristotle
On Heidegger's interpretation (see Sheehan 1975), Aristotle holds that since every meaningful appearance of beings involves an event in which a human being takes a being as—as, say, a ship in which one can sail or as a god that one should respect—what unites all the different modes of Being is that they realize some form of presence (present-ness) to human beings.
[...]
The foregoing considerations bring an important question to the fore: what, according to Heidegger, is so special about human beings as such? Here there are broadly speaking two routes that one might take through the text of Being and Time. The first unfolds as follows. If we look around at beings in general—from particles to planets, ants to apes—it is human beings alone who are able to encounter the question of what it means to be.
[...]
Moreover, if science may sometimes operate with a sense of awe and wonder in the face of beings, it may point the way beyond the technological clearing, an effect that, as we shall see later, Heidegger thinks is achieved principally by some great art.
By revealing beings as no more than the measurable and the manipulable, technology ultimately reduces beings to not-beings. — SEP: Martin Heidegger
Aristotle’s study does not concern some recondite subject matter known as ‘being qua being’. Rather it is a study of being, or better, of beings—of things that can be said to be—that studies them in a particular way: as beings, in so far as they are beings.
Of course, first philosophy is not the only field of inquiry to study beings. Natural science and mathematics also study beings, but in different ways, under different aspects. The natural scientist studies them as things that are subject to the laws of nature, as things that move and undergo change. That is, the natural scientist studies things qua movable (i.e., in so far as they are subject to change). The mathematician studies things qua countable and measurable. The metaphysician, on the other hand, studies them in a more general and abstract way—qua beings. So first philosophy studies the causes and principles of beings qua beings. — SEP: Aristotle’s Metaphysics
It is not easy to think about God’s relationship to the created world, because without such a world there can be neither space nor time. Not space, because space is nothing more than the existence of bodies, where bodies are beings that possess parts outside of parts, and so constitute the three-dimensional extension that we think of as space. — SEP: Thomas Aquinas
Similarly, according to Aristotle, things in the world are not beings because they stand under some genus, being, but rather because they all stand in a relation to the primary being, which in the Categories he says is substance. This explains in part why he says in the Metaphysics that in order to study being one must study substance. — SEP: Aristotle’s Categories
Recall that for Wolff a being in the most general sense is any possible thing. [...]
Wolff explains:
"A being is called composed which is made up of many parts distinct from each other. The parts of which a composite being is composed constitute a composite through the link which makes the many parts taken together a unit of a definite kind."
In one respect, simple beings and composite beings are not simply two different species of beings. It is not the case, for example, that within the realm of all possible things simple beings exist separate from, and in addition to, composite beings. — SEP: Christian Wolff
Heidegger sees modern technology as the fulfillment of Western metaphysics, which he characterizes as the metaphysics of presence. From the time of the earliest philosophers, but definitively with Plato, says Heidegger, Western thought has conceived of being as the presence of beings, which in the modern world has come to mean the availability of beings for use. In fact, as he writes in Being and Time, the presence of beings tends to disappear into the transparency of their usefulness as things ready-to-hand. — SEP: Postmodernism
Forms are marked as auto kath auto beings, beings that are what they are in virtue of themselves. — SEP: Plato’s Middle Period Metaphysics and Epistemology
There are pages and pages of this, but I have other sources aside from the SEP if you need them.