In the fiction I enjoy, sentient alien civilizations are extremely common and frequently interact with humans. It is generally acknowledged that universes like those of Star Trek and Star Wars, where practically every solar system has a sentient and usually humanoid race, are next to impossible. It is recognized by everyone as something extremely fun, but not an idea to be taken too seriously. Nevertheless, there is a general expectation in the circles I frequent that there is an alien race of sentience out there somewhere. A great deal of money is spent every year to fund the Search for Extra Terrestrial Intelligence (SETI) with the expectation that once we find this alien race we will be able to communicate with it. This is something of which I am not convinced for reasons I will lay out below.
Before I directly tackle the issue of alien races, it is useful to discuss the term "qualia" for the purposes of this discussion. Philosophers, in discussing the way we perceive the world, have often made a distinction between the world itself and the way we perceive it. When I see a red flower, what exists in the actual world is a series of molecules of certain composition so as to reflect light of a particular spectrum. When perceived by me, this light enters into the human eye. Rather than seeing things as such, however, I see red. The aspect of this sensory experience that we label "red" is referred to by philosophers as the experiences "qualia." The reason for explaining this will become clear later.
I am not, in my understanding of the world, a complete empiricist. That is, it seems apparent to me that there are some aspects of human understanding that come to us before experience. Nevertheless, I am well aware of the monumental role that experience plays in our formation of ideas and especially in our use of language. When I and friend get together for a coffee and comment that the coffee is particularly bitter that day, we understand each other because of our agreement on the word "bitter" as referencing a certain qualia in our experience. Or, earlier in this article, when I talked about a red flower, you understood my meaning on the basis of your association of the words "red" and "flower" with given qualia in your experience. It even seems that many of our more abstract ideas are ultimately derived from empirical experiences of certain kinds. Basic concepts of cause and effect, spatial relation, the basic distinction between subject and object, and even mathematics, are quite possibly a priori (existing before experience), but other abstract concepts, such as society or friendship, stem from experience.
This aspect of language development becomes an impediment when our sensory experience of the world differs significantly. One needs look no further than the case of a man born blind. Such a man might have color words in his vocabulary, but they are essentially meaningless. I have heard that some blind people can distinguish color by touch, but even here there association for color vocabulary is tactile and not visual and therefore substantially different from the average seeing person's experience of the world. For our purposes, however, let us discuss a blind man who is unable to make even this distinction. For him, color words simply refer to a vague experience which he knows others have, but the qualia of which he has never experienced. If this man hears a poem talking about a women's raven black hair, or has a friend talk to him about a brilliant red sunset, he cannot really fathom what is really being said. This is not a lack of intelligence, but merely a lack of relevant experience, and because of his blindness he has no way of gaining this experience. The blind man does, however, have the rest of his common human experience to draw on in conversation, and this more than compensates for his handicap.
But what of a being possessed of an entirely different kind of experience? It is probable that any alien race would evolve (or be created) with an array of sensory organs utterly foreign to creatures of earth. Being bound by human sensory experience, I can't really imagine what this would be, just as the blind man can't really imagine what seeing is like, but that does not make it impossible. Indeed, given the fact that an alien would be of entirely different genetic makeup (if it even had genes), this scenario seems most likely. Any number of ways of sensing the world could be just as effective as our sensory modes without being related at all in their qualia. And, unlike the blind man, such an alien would have no common human experience upon which to build a connection. A blind man may not see, but he can still feel and hear and his experience of emotional qualia is effectively the same. Given the probability of the alien's otherness, and the nature of language discussed above, how likely is it that an effective form of communication could be developed with an alien race?
There is, however, one solid objection to the claims made above that deserves attention. I was talking with my friend Jon Shiefer regarding my ideas about communication with aliens and he brought up the possibility of mind reading. If aliens were psychic, wouldn't that solve the problem? I had thought about this some, but had not given it too deep of consideration. It did seem to be at least a possible solution. Ultimately, though, given the considerations I have brought up above, I think it, too, ultimately fails for two reasons: the first is that an alien possessed with telepathic equipment would have it for the purposes of reading other minds of his species. There is no reason to think it would even be equipped to tune in to the human brain. Even if it did, however, the alien would experience a set of bizarre and utterly foreign qualia that would mean nothing to its mind. Essentially, it would seem that any telepathic ability would consist of some system that was able to pick up the electrical signals of another's brain and interpret them. Again, a human seeing a flower has a certain set of photons enter his eye, which his brain then interprets into colors using a specific part of the brain that functions for sight. In other words, a human brain possesses a specific faculty for interpreting human sight impulses. What faculty would the alien possess that could interpret the signals?
Therefore, given at least purely naturalistic considerations, it seems that communication with aliens would be impossible and that programs like SETI would be a waste of time. There are, however, two possible considerations that deserve attention. The first, following the naturalistic outlook I have assumed for this article, is that of a common genetic ancestry. Some stories have it that the world was genetically seeded by aliens, others that at some time in the past being of terrestrial genetic origin left Earth. If this happened, then there would be a common genetic heritage that might lead to a similar experience of the world that could possibly allow for communication between species. Finally, there is the possibility that is the one most significant to me. If one believes, as I do, that the universe was designed by God, a wrench is thrown into the purely naturalistic model, and I don't just believe in any God, I believe in the God of the Bible. According to that text, humans are made in the image of God. It is widely regarded by theologians that our minds are a crucial part of that image. To be sentient is at least part of what it is to be made in the image of God and apart from this image sentience cannot exist. God is not embodied (apart from Christ), but might there be something native to conscience itself that would lead any sentient being, once embodied, to experience the world in a certain way? Even lacking this, might two separate sentient beings created by God have some common ground in their spirituality, even if not in their physical experience of the world? If these common grounds existed, then they could potentially form the basis for a shared language. I cannot say that they must exist if God is added into the picture, but then I also cannot see anything that would forbid them. If then, God exists, there might be some hope that someday, if we meet aliens, we might find a way to talk with them.