The Word “Thing”
In his Ethics Spinoza has a curious passage concerning the common word “thing”: “But not to omit anything it is necessary to know, I shall briefly add something about the causes from which the terms called Transcendental have had their origin—I mean terms like Being, Thing, and Something. These terms arise from the fact that the human body, being limited, is capable of forming distinctly only a certain number of images at the same time (I have explained what an image is in P17S). If that number is exceeded, the images will begin to be confused, and if the number of images the body is capable of forming distinctly in itself is greatly exceeded, they will all be completely confused with one another…. But when the images in the body are completely confused, the mind also will imagine all the bodies confusedly, without any distinction, and comprehend them as if under one attribute, namely, under the attribute of Being, Thing, and so forth… These terms signify ideas that are confused in the highest degree.” (P40) Spinoza evidently believes that the word “thing”, as philosophers employ it, is a defective word expressing a defective concept, because it signifies no determinate kind or sort or type. Presumably, then, it should be banned from serious discourse and certainly not relied upon in theoretical contexts. What it means is obscure at best.
And yet the word finds its way into philosophical discourse at the highest level, as if it cannot be done without. Let me mention three disparate examples. First, there is Descartes’ use of the phrase “thinking thing”: not “thinking subject” or “thinking self” or even “thinking substance”—as if Descartes is reluctant to say anything positive about what the thing that thinks is. We may not know what the nature of this thing is, but at least we know that it thinks—whatever precisely “it” is. Second, there is Kant’s use of “thing-in-itself”: this thing is also an I-know-not-what, though we know that there must be such a thing. Again, Kant doesn’t want to enter into any conjectures about what manner of thing this thing-in-itself might be—even to call it an “object” might be overreaching—so he sticks to the indeterminate term “thing”. Third, we have Wittgenstein’s well-known remark: “It is not a something, but not a nothing either!” (Philosophical investigations, 304) This sentence could be paraphrased as, “It is not a thing, but it is not not a thing either!” Once again, the thought is that we have run out of descriptive resources and are forced back to the non-descript word “thing”: we have reached the limit of language, the point at which all description fails us. We use the word “thing” when we can find nothing better to say—nothing more informative, more definite.
Here is how the OED defines “thing”: “an object that one need not, cannot, or does not wish to give a specific name to”. The word “object” jars here because “thing” seems broader than “object”, but for our purposes the definition captures the philosophical use of “thing” nicely. We use the word “thing” when we cannot use a more specific term—when we have no name or description for what we are referring to. Thus the word functions as an expression of ignorance: we use it when we need to be maximally general, vague, or noncommittal. We use it in contexts of epistemic limitation. Consider Hamlet’s famous declaration, “There are more things in heaven and earth, Horatio, than are dreamt of in our philosophy”: here the schematic “things” expresses the lack of knowledge to which Hamlet is drawing our attention—things whose nature and type we know nothing of. Hamlet is alluding to what lies beyond our conceptual scheme, even our imagination (“dreamt of”)—to the unknown or unknowable.
This, then, suggests an answer to the question troubling Spinoza: What are these schematic bloodless words for? Are they just confusions brought about by the way we form concepts, the mind misfiring? The answer, I suggest, is that we have these words because we recognize that we are cognitively limited—we know that we don’t know. We want to be able to speak about the unknown and unknowable, and to do that we need words that don’t commit us as to type—words without descriptive content. The concepts they express are not confused and pointless but exactly tailored to their purpose, namely to permit reference to what we do not and maybe cannot conceive. We might call them “horizon words”. There are “things” out there, over the horizon, which we don’t know how to describe or classify or get our minds around. To put it in philosopher’s jargon, we have the word “thing” because we are realists—because we don’t want to limit reality to what we know or could know. 
The point applies sharply to quantifier words like “something”, “everything”, and “nothing”. We want these expressions to have maximum generality, stretching beyond what we can know or conceive or dream. Thus “everything” means “every…single…thing”, without restriction. We need a word like “thing” if we are going to encompass every last thing (!) in reality. Restricted quantifiers like “every man” or “every elementary particle” won’t cut it. The word “thing” exists because language recognizes its own limitations—it refers to what it cannot refer to. That is, it refers to things it is incapable of describing. The concept thing is part of our conceptual scheme because our conceptual scheme is limited; it concedes the possible blankness of our thought concerning reality. We speak brightly of dogs, mountains, numbers, and electrons—things we can conceive, at least in some measure—but we also speak darkly of things that we cannot conceive but which might yet exist. Hence we find no tension in the phrase “unknowable things”. If we didn’t believe in such possibilities, we wouldn’t need the word “ thing” in its current meaning; there would be, so far as we are concerned, nothing beyond dogs, mountains, numbers, and electrons—nothing over the horizon.
Does anything fail to be a thing? Frege thought that concepts are not objects, so not everything is an object: but are concepts things? Surely they are, for they are real (for Frege). Are Platonic universals things? What else could they be (if they exist)–nothings? Is God a thing? He is certainly something, so he must be a thing of some sort—some…thing. Are events things, or thoughts, or numbers? Check, check, and check. Every last thing is a thing—it’s what anything has to be. The word “thing” applies to absolutely everything, trivially so; and it enables us to speak of what we cannot know or conceive or imagine. Everything we know is clearly a thing, but so is everything we don’t know. As Spinoza suggests, “thing” belongs with “being” in that both words aim to encompass the whole kit and caboodle (notice how language strains at its edges). It is the word we use in philosophical contexts when we mean to abstract away from the known part of reality and reach out to the very limits of reality. So far from being confused or pointless, it is a word with a clear and definite purpose—to make sure nothing (no…thing) is excluded. To speak of “things” is to speak of what is, immanently or transcendentally (to echo Spinoza). It is a very good word.
 There is an old horror film called simply The Thing and the point is that its hapless victims know not what it is that is decimating them. And then there is the timeless cliché, “Someone…or some thing”.