In many instances, perhaps, this is true. When I say human, there is a general agreement of the biological factors which are the minimum prerequisites for what we call humanity. If you understand the language reasonably well, then when I talk about humans, you won't think I'm talking about toaster ovens or squirrels. We have named a very specific object, which can be measured or differentiated precisely as a human being.
Now if I were to say, for example...
Humans are idiots.
...(which, I might add, wouldn't be entirely improbable), we know that we are speaking about these particular things, these human things. If I want to get very priggish about it, I could consult a biological text to see what trait or traits are necessarily indicative of humanity. For the purposes of this discussion, I will not, however, and will rely on the general assumption that the name tagging metaphor of language mentioned above is quite applicable in this case. We have differentiated among the totality that presents itself to us, we have have isolated a discrete object, and we have affixed that name tag (which reads human) to it.
Let's skip the verb (are) for a moment and deal with the word idiots. It's true that the word is—in a theoretical sense—a name tag that we affix an object, but there is no absolute standard, as there is for humans. In other words, if I refer to Michele Bachmann as an idiot (as I am wont to do), it is conceivable that you might disagree with me. You might argue that the category of 'idiots,' although applied to specific objects, is not in itself terribly specific and is subject to interpretation. Let's refer to Merriam-Webster, where idiot is defined as a foolish or stupid person. Obviously, these adjectives foolish and stupid require some judgment on the part of the speaker. We don't all believe the same things are foolish and stupid. Therefore, although there is a general category of idiocy at our disposal in the English language, the living word idiot is invested with a particularity by my personal judgment, which is informed by all this baggage that I collectively call 'my subjectivity.'
This is one of many ways that the language evolves. With words like idiot, the judgment as to what constitutes an idiot may shift in a given direction over time thus resulting in a slippage in the category as a whole. For example, perhaps idiot will become in time more closely associated with a person who prefers ignorance to unpleasant truth. Let's suppose this shift is brought about by the influence of one speaker upon others, and others upon others, and so on and so on. This may narrow the category and delimit the concept in the course of a few generations. Thus, the name tagging metaphor is somewhat problematic in the case of discretionary words like these. If there isn't a solid, specific thing we can tag, then how can we keep the idea stable?
But let's move on to the point of this entry—and that is the verb are located in the middle of the sentence above. In the English language, are is a conjugation of the verb to be—or, in its gerundial form, being.
What exactly are we name tagging in this case of the word being? Is there a thing there that we wish to classify and name? Well, you might answer that since to be can be defined in a dictionary, then there is an essential somethingness there which we might differentiate from other somethings in our world. And this is a mistake, I think, of ontology (the study of being).
In the sentence above, are is merely the connective tissue between two named objects. It identifies them as equivalents. Humans are idiots. In other words, it describes the relationship between the two objects tagged around it rather than indicating a thing in itself.
It has become a custom (one which postmodern theory has exploited and deconstructed) to regard words as symbols which point to real things. The words themselves are nothing. When a baby is born, the parents might name it Helen, Mary, Kiki, Pilot Inspektor, 67534, or Barfhead, but this is only the term by which the real thing (the baby) can be spoken about and addressed. When we see words, we therefore (almost instinctively) suppose that there is something behind them, some actual thing that is being pointed at.
This is where ontology gets into trouble. Because there is a linking verb being, which is a relational word rather than an object tag, we nevertheless suppose that there is some actual thing called being. And the philosophical questions assert themselves: What constitutes being? What does it mean to be? This word, since it is so obscure, since it points to nothing, takes on vast metaphysical connotations. We imagine that 'being' is something that we do—something primal that derives us and may possess qualities, even if these qualities are as obscure and elusive as being itself.
Now, some of you may be tempted to argue that this is all semantical game-playing on my part because we understand that when one says 'being' the thing one is really getting at is 'existence.' I disagree. Existence is a thing. It is a specific object that may be tagged. Philosophy may obfuscate it, but it's merely a status of presentness in the world (the world in this case incorporated the whole known universe and all that we may conceive of*). Anything that can not potentially be found or conceived must not exist, in the way that we understand existence. We shouldn't lose sight of the fact that existence is a relative term; it is relative to us, the humans who use it. It just means that I am here, in which case 'here' is a given location within the totality of the known universe. Philosophers (mainly the dead ones) liked to imagine that existence happens (or might happen) without respect to us, the people who use the word. This radical skepticism is almost religious in its theoretical reliance upon an a hypothetically unapparent world. In order for existence to occur outside of the bounds of my understanding or apprehension, it necessarily means that existence is not conceptually reliant upon my subjective understanding of it—which is ridiculous.
But being isn't existence, exactly. Being is far more mysterious in that it isn't merely a presentness in the world; it's a status devoid of content. To assert that 'I am' as Descartes did is only a manipulation of language. What would it mean if somebody said 'I'm not'? Well, then how can you assert an I, if it means existence? Clearly, being or not being doesn't add anything to the status of the self, the I; it just gives the appearance of a dilemma because we are seeking the thing behind the word being, which is a void.
When I say that I am, it's akin to a mathematical equation like this:
Well? Twelve equals what? Does the equation assert the existence of 12 or does it merely defer the definition of twelve? There is a relationship indicated, but one object can't have a relationship with no objects. Relationships are contingent upon at least two variables.
So when I say, I am—the question becomes: I am what? So long as I am able to identify myself as the I of the sentence, I have only established that I relate to something else. But to what? If there is no other term to relate to, I have asserted even less than my existence: I am everything and nothing. I am deferred. I am a problem left for another day...
* Which isn't to say that our conceptions exist materially, but only that they exist as conceptions.