There then followed several transmissions from PC3 which the earthlings did not understand. They were
T, Si → Sy = 1.35 × 1012 years (breakthrough)
Si = atmospheric wave motion, tactile, radar return
Sy = variable pitch frequencies combined with radar-return configurations, or SRs (sound-radar)
Sn = SR, + SR2 (+ = assert)
C = 1 (Int, Soc, Sy)
Each item of information was followed by the query: “What’s yours?” Then: “What’s your C-type? Are you C1? C2? C3? Over and out. Come back.”
A puzzled silence from the earthship transmitter, then: “Say sgain.” Then: “Say again longer [i.e., Explain]. What is C-type? What is Si? Sy? Si ? Sy breakthrough? T? Sn?
After many weeks of transmissions, dogged human effort, and an unflagging good-humored patience from the PC3 transmitter, the following explanations were spelled out:
T = time
Si = sign
Sy = symbol
Sn = sentence
T, Si → Sy 1.35 × 1012 years means how long ago in PC3 years we made the breakthrough from sign communication to symbol communication, i.e., 13,500,000 years.
Before that, we communicated by touch, sounds of different pitches, and a radar-like reception of reflected sound. Like a bat, said an earthling. Imagine bats flying blind and emitting squeaks of different musical pitches.
Sy, or symbols, were formed by combining frequency clusters (e.g., chords of musical squeaks) with the percept or radar configuration formed by the radar-return of this or that object. Thus, instead of the word ball being applied to the round thing you earthlings play with, our primitive word was applied to the jagged radar-configuration of the double-bladed sickle with which our ancestors harvested our atmospheric algae. Our “words” or symbols are combinations of musical chords (for objects), arpeggios (for action words, verbs) with the corresponding radar percepts, just as your words ball, yellow, slice are combinations of sound configurations and visual percepts (though we don’t quite understand what you mean by “visual” and “see”).
Sn is a sentence, uniting two of these sound-radar configurations, so:
means: Your spaceship is descending.
EARTHSHIP: True. Very interesting. We read. Request permission to land. We could exchange much more information by meeting and talking.
PC3: Not quite yet. You haven’t answered our question about C-type.
EARTHSHIP: What do you mean by type of consciousness?
PC3: We are C1s. We wanted to know whether you are C1s or C2s or C3s.
EARTHSHIP: What is a C1?
PC3 (patiently): We told you. C = 1 (Int, Soc, Sy).
EARTHSHIP: What does that mean?
PC3 (patiently): It means that in order for the individual consciousness to be activated, it is required that there be a Soc, that is, a society, that is, two or more persons; an exchange of Sy, that is, symbols; and an Int, that is, an intersubjective relationship in which there is agreement about the symbol used and the thing that is talked about.
EARTHSHIP: Oh.
PC3: And you?
EARTHSHIP: We’re much the same. Now may we request permission to—
PC3: Just a moment. It is still necessary to establish your C-type. We are C1s, that is, first-order consciousness. Through the centuries we have learned by painful experience that there are at least two other C-types, C2s and C3s. C1s and C3s are benign. C2s are dangerous. Which are you?
EARTHSHIP: Say again. What’s the difference?
PC3: A C1 consciousness is a first-order consciousness, or what you would call a preternatural consciousness — according to the dictionary your computer transmitted.
EARTHSHIP: It is? Say again. Preternatural?
PC3: Well, something like the consciousness of a child grown mature and sophisticated but maintaining its innocence permanently and avoiding the malformations of self-consciousness, enjoying the beauty of our planet and each other and our science and art without weariness, boredom, fear, guilt, or shame. Like what you call the Helen Keller phenomenon.
EARTHSHIP: How do you know about her?
PC3: One of our cosmological linguists just arrived. This is he speaking. We’ve been monitoring you for years. Switch to Earth-L, English-speaking? German? French?
EARTHSHIP: American English.
PC3: Got it. I read. What can we do for you?
EARTHSHIP: What do you mean by the Helen Keller phenomenon?
PC3: The joy of consciousness and the discovery of the Cosmos through the mediation of symbols and the cooperation of others and the preservation of this joy against the incursions of boredom, fear, anger, despair, shame, and the love of war and death and the secret desire for the misfortune of others.
EARTHSHIP: Check. Did you say shame?
PC3: We have observed that C2s experience shame. For example, do you wear clothes?
EARTHSHIP: Yes.
PC3: Despite the controlled environment of your ship?
EARTHSHIP: Yes.
PC3: Why?
EARTHSHIP: Ah, custom. Aesthetics.
PC3: Aesthetics? Explain.
EARTHSHIP: Later, when we land. May we land?
PC3: Not yet. What is your C-type?
EARTHSHIP: What is a C2 consciousness?
PC3: A C2 consciousness is a consciousness which passes through a C1 stage and then for some reason falls into the pit of itself.
EARTHSHIP: The pit of itself?
PC3: In some evolving civilizations, for reasons which we don’t entirely understand, the evolution of consciousness is attended by a disaster of some sort which occurs shortly after the Sy breakthrough. It has something to do with the discovery of the self and the incapacity to deal with it, the consciousness becoming self-conscious but not knowing what to do with the self, not even knowing what its self is, and so ending by being that which it is not, saying that which is not, doing that which is not, and making others what they are not.
EARTHSHIP: What does that mean?
PC3: Playing roles, being phony, lying, cheating, stealing, and killing. To say nothing of exotic disordering of the reproductive apparatus of sexual creatures.
EARTHSHIP: What does that mean?
PC3: Exploitative sex.
EARTHSHIP: Exploitative sex?
PC3 (consulting computerized earth-slang dictionary): It seems to mean what you call “screwing everything in sight,” not only 
to 
and to but to and to and + + and + + —to mention a few of the simpler combinations.
EARTHSHIP: That is what is called “freedom of sexual preference.”
PC3: Call it what you like. We are not interested. What concerns us is our experience with C2s whom we have allowed to land on PC3. They are usually polite at first, but always turn hostile, deceptive, and end by attempting to screw (is that the right word?) any creatures on PC3 which have an opening or a protuberance. We could tolerate their odd sexual behavior, but they were also sentimental and cruel — or rather sentimental, therefore cruel. One goes with the other. They are mainly interested in self-esteem. We are afraid of C2s. They do not know themselves or what to do with themselves.
EARTHSHIP: What about you? What do you do about your consciousness and your selves?