I can't prove there are any, perhaps no one will ever prove there are any, but I still wish they were out there. We can study the problem with science and can conclude there is nothing to rule it out, or that even though there is some good circumstantial evidence to suggest they are out there, we still won't know for sure until we make physical contact, communicate, or find some kind of archaeological evidence of their existence. We don't know whether or not there are other intelligent beings in the cosmos, and even if they exist, we don't know whether they are extremely rare, extremely common, or if its just us and no one else.

Why is this important to me? I need to know whether we are just a lucky accident, a freak, or if we are a result of a natural process that has repeated itself elsewhere--the same laws of nature yielding similar results under similar circumstances. I need to know this personally, it matters a great deal to me. It tells me what kind of universe I live in. I want to live in a universe populated by diverse life forms, cultures, intelligences, civilizations. I don't expect them to be like us (except that perhaps they are constructed and governed by the same physical laws), but I don't want to think we are alone. I don't want to live alone in this universe, the thought saddens me. In fact, it scares me.

Right now, my best guess is that life is probably pretty common throughout the universe, at least single-celled life is. I don't know for sure, of course, but what we know of life on earth suggests it is probably pretty common out there. But more complex life forms are another matter. Thinking creatures are totally speculative, and other civilizations and cultures are anyone's guess.

If we ever find another sentient species out there, we'll have our answer. But if we don't, we won't have proved the opposite. This is the kind of question that has only two possible answers: 'yes', and 'we don't know'.

I am self-aware enough to recognize this need to know in myself is very similar to the search for a god that I see in others. Perhaps it originates from the same place, some part of our wiring that makes us look for something greater...or at least...something equal. Maybe so.
But I have already resigned myself to living in a universe with no Father. I don't want to live in that universe without brothers. I do not want to be alone.