Today, the question of the existence of any other reason, there are two logical starting point. This is a supposition that it exists (in the near field of contact), or the assumption that we are absolutely alone in this universe. (It is possible, however, and an intermediate solution: for example, the conclusion that the unknown civilization live in such a mind-blowing expanses where our telescopes can not penetrate, but here we are interested only in the extreme points of view..) We have seen that the facts, which now has a science (and the complete absence of any kind was evidence of the existence of other civilizations in the area controlled by us - this is a fact), alone can not clarify the analyzed object. By themselves, they do not say, and can not speak strongly about anything. However, if we take as a working hypothesis or that of the extreme assumptions, they will be very, very eloquent.