For virtually every change we see, we tend to seek some cause. And when we find no cause on the scene, we'll postulate that one exists, even though we might be wrong. We do this so consistently that I wouldn't be surprised to find that brains have built-in tendencies to try to represent all situations in certain special ways:
THINGS. Whatever we may see or touch, we represent the scene in terms of separate object-things. We do the same for representing processes and mental states. In languages, these object-symbols tend to correspond to nouns. DIFFERENCES. Whenever we discern a change or just compare two different things, we represent this as a difference thing. In languages, these often correspond to verbs.
CAUSES. Whenever we conceive of an action, change, or difference, we try to assign a cause to it — that is, some other person, process, or thing that we can hold to be responsible for it. In languages, causes often take the forms of things. CLAUSES. Whatever structures we conceive are dealt with like single things. In languages, this corresponds to treating an entire phrase as though it were a single word.
In English, almost every sentence form demands some sort of Actor noun — and I think this reflects the need to find a motive or a cause. Consider how we place that it in Soon it will begin to rain. We're always chopping complex situations into artificially clear-cut chunks which we perceive as separate things. Then we notice various differences and relationships among those parts and assign them to various parts of speech. We string our words into clauses and our clauses into chains, often interrupting one by inserting fragments of others inside it, yet proceeding as though there were no interruptions at all. It has been alleged that the construction of such structures is unique to the grammar-machinery of language, but I suspect that languages evolved those forms because of mechanisms deeper in the grain of how we think. For example, when we talked about visual ambiguity, we saw that our vision-systems are highly proficient at representing structures that interrupt one another. This suggests that both our visual and linguistic abilities to deal with interruptions could be based on similar methods with which we manage what is represented in our short-term memories.
In any case, our brains appear to make us seek to represent dependencies. Whatever happens, where or when, we're prone to wonder who or what's responsible. This leads us to discover explanations that we might not otherwise imagine, and that helps us predict and control not only what happens in the world, but also what happens in our minds. But what if those same tendencies should lead us to imagine things and causes that do not exist? Then we'll invent false gods and superstitions and see their hand in every chance coincidence. Indeed, perhaps that strange word I — as used in I just had a good idea — reflects the selfsame tendency. If you're compelled to find some cause that causes everything you do — why, then, that something needs a name. You call it me. I call it you.