Extraterrestrial Civilizations Read Online Free Page A

animals.
    And yet there may be some one kind of tool that marks the clear boundary line separating the most intelligent species from all others.
    We have not far to seek. The key lies in the taming and use of fire. There is definite evidence of fire’s having been used in caves in China in which an earlier hominid species,
Homo erectus
, dwelt at least half a million years ago. The discovery has never been forgotten.
    No human society existing anywhere on Earth now lacks the knowledge of how to ignite and use a fire. No nonhuman species whatever has ever made the slightest advance in the direction of the use of fire, as far as we can tell.
    Suppose we define “human intelligence” as: A level of intelligence high enough to allow the development of methods for igniting and using fire.
    In that case, to the question of whether the equivalent of human intelligence exists on Earth in nonhuman species, the answer must be: No! —The human being stands alone.
    This might seem unfair; and the result of an arbitrary, self-serving definition. Let’s see if it is by comparing the dolphin and the human being.
    The dolphin spends his life in water and the human being spends his life in air. Water is a viscous medium, much more viscous than air. It takes much more effort to force one’s way through water at a given speed than it does through air. (Anyone who has tried to run when partly immersed in water knows this is so.)
    In order to attain speed in water, the dolphin has evolved a streamlined form to reduce water resistance. Moving through air, however, the human being does not require streamlining. The human being can develop a very irregular form and still be capable of fast motion.
    For that reason, the human being can develop complicated appendages, while the dolphin cannot. The dolphin’s streamlining allows it two stubby paddles and a fluke as its only maneuverable appendages, and these are useful only for propulsion and guiding.
    To put it most briefly, human beings, because they live in air, can develop hands with which they can manipulate their environment. Dolphins, because they live in water, cannot develop hands.
    Then again, the fire that early humans learned to handle is the radiation of heat and light that results from a rapid energy-yielding chemical reaction. The most common energy-yielding large-scale chemical reactions that are useful in this connection are those resulting from the combination of substances containing carbon atoms, hydrogen atoms, or both (“fuel”) with the oxygen in the air. The process is called combustion. Fire cannot exist under water since free oxygen is not present and combustion cannot take place.
    Therefore, even if dolphins had the intelligence to conceptualize fire, and to work out, mentally, the steps needed to tame and use it, they would be unable to put any of it into practice.
    We see now, however, that the human use of fire could be considered as no more than the accidental by-product of the fact that the human being lives in air, and is not in itself necessarily a true measure of intelligence.
    The dolphins, after all, even though they are unable to manipulate the environment and unable to build and use a fire, may have in their own way developed a subtle philosophy of life. They may have worked out, more usefully than we have, a rationalization of living. They may interchange more joy and good will with their feelings and understand more. The fact that we cannot grasp their philosophy and their modes of thought is no evidence of their low intelligence, but is perhaps evidence of our own.
    Well, perhaps!
    The fact is, though, that we don’t have any evidence of the dolphin’s philosophy of life. The lack of that evidence may be entirely our fault, but there’s nothing we can do about it. Without evidence, there is no way of reasoning usefully. We can look for the evidence and someday, perhaps, find it, but until then, we can’t reasonably assign human intelligence to the