The very definition of "alien"

A New World, if We Can Take It (Whitley Strieber)

In reality, the way the visitors function and what happens to people in their proximity suggests that they perceive the world very, very differently from the way we do. For example, when you are face to face with the small gray beings that form such a large part of the presence we see, and figure so extensively in its folklore, there is no sense that you are with people. Rather, it's like being with animals who are much more intelligent than you are. This is because there is absolutely no cultural familiarity at all. None.

How can officials engage with somebody whose meaning lies beyond a gap far more vast than that between us and, say, dolphins? We haven't the slightest idea what cetaceans may be saying to each other, or even what language means to them, if anything. And our visitors -- even those who appear to engage with us verbally -- are far, far more different from us than any earthly species.