Excerpts from Gödel, Escher, Bach by Douglas Hofstadter (via Occam’s Beard)
In these examples of decipherment of out-of-context messages, we can separate out fairly clearly three levels of information: (1) the frame message; (2) the outer message; (3) the inner message. The one we are most familiar with is (3), the inner message; it is the message which is supposed to be transmitted: the emotional experiences in music, the phenotype in genetics, the royality and rites of ancient civilations in tablets, etc.
To understand the inner message is to have extracted the meaning intended by the sender.
The frame message is the message “I am a message; decode me if you can!”; and it is implicitly conveyed by the gross structural aspects of any information-bearer.
To understand the frame message is to recognize the need for a decoding-mechanism.
If the frame message is recognized as such, then attention is switched to level (2), the outer message. This is information, implicitly carried by symbol-patterns and structures in the message, which tells how to decode the inner message.
To understand the outer message is to build, or know how to build, the correct decoding mechanism for the inner message.
This outer level is perforce an implicit message, in the sense that the sender cannot ensure that it will be understood. It would be a vain effort to send instructions which tell how to decode the outer message, for they would have to be part of the inner message, which can only be understood once the decoding mechanism has been found. For this reason, the outer message is necessarily a set of triggers, rather than a message which can be revealed by a known decoder.
The formulation of these three “layers” is only a rather crude beginning at how meaning is contained in messages. There may be layers and layers of outer and inner messages, rather than just one of each. Think, for instance, of how intricately tangled are the inner and outer messages of the Rosetta stone. To decode a message fully, one would have to reconstruct the entire semantic structure which underlay its creation— and thus to understand the sender in every deep way. Hence one could throw away the inner message, because if one truly understood all the finesse of the outer message, the inner message would be reconstructible.
What makes us see a frame message in certain objects, but none in others? Why should an alien civilization suspect, if they intercept an errant record, that a message lurks within? What should make a record any different from a meteorite? Clearly its geometric shape is the first clue that “something funny is going on”. The next clue is that, on a more microscopic scale, it consists of a very long aperiodic sequence of patters, arranged in a spiral. If we were to unwrap the spiral, we would have one huge linear sequence (around 2000 feet long) of minuscule symbols. This is not so different from a DNA molecule, whose symbols, drawn from a meager “alphabet” of four different chemical bases, are arrayed in a one-dimensional sequence, and then coiled up into a helix. Before Avery had established the connection between genes and DNA, the physicist Erwin Schrödinger predicted, on purely theoretical grounds, that genetic information would have to be stored in “aperiodic crystals”, in his influential book What is Life? In fact, books themselves are aperiodic crystals contained inside neat geometrical forms. These examples suggest that, where an aperiodic crystal is found “packaged” inside a very regular geometric structure, there may lurk an inner message.
The three levels are very clear in the case of a message found in a bottle washed up on a beach. The first level, the frame message, is found when one picks up the bottle and sees that it is sealed, and contains a dry piece of paper. Even without seeing writing, one recognizes this type of artifact as an information-bearer, and at this point it would take an extraordinary—almost inhuman—lack of curiosity, to drop the bottle and not look further. Next, one opens the bottle and examines the marks on the paper. Perhaps they are Japanese: this can be discovered without any recognition of the inner message being understood—it merely comes from a recognition of the characters. The outer message can be stated as an English sentence: “I am in Japanese.” Once this has been discovered, then one can proceed to the inner message, which may be a call for help, a haiku poem, a lover’s lament…
It would be of no use to include in the inner message a translation of the sentence “This message is in Japanese”, since it would take someone who knew Japanese to read it. And before reading it, he would have to recognize the fact that, as it is in Japanese, he can read it. You might try to wriggle out of this by including translations of the statement “This message is in Japanese” into many different languages. That would help in a practical sense, but in a theoretical sense the same difficulty is there. An English-speaking person still has to recognize the “Englishness” of the message; otherwise it does no good. Thus one cannot avoid the problems that one has to find out how to decipher the inner message from the outside; the inner message itself may provide clues and confirmations, but those are at best triggers acting upon the bottle finder (or upon the people whom he enlists to help).
Similar kinds of problem confront the shortwave radio listener. First, he has to decide whether the sounds he hears actually constitute a message, or are just static. The sounds in themselves do not give the answer, not even in the unlikely case that the inner message is in the listener’s own native language, and is saying, “These sounds actually constitute a message and are not just static!” If the listener recognizes a frame message in the sounds, then he tries to identify the language the broadcast is in— and clearly, he is still on the outside; he accepts triggers from the radio, but they cannot explicitly tell him the answer.
It is in the nature of outer messages that they are not conveyed in any explicit language. To find an explicit language in which to convey outer messages would not be a breakthrough— it would be a contradiction in terms! It is always the listener’s burden to understand the outer message. Success lets him break through into the inside, at which point the ratio of triggers to explicit meanings shifts drastically towards the latter. By comparison with the previous stages, understand the inner message seems effortless. It is as if it just gets pumped in.
In multisense realism, I think of the three levels of GEB semiotics not as absolutes of frame, outer, and inner, but as relative frames of increasingly inner qualities. The bottle is read optically (inner to your visual experience but outer to your body and self), the text is read optically and typographically (inner to your semiotic experience but outer to your ‘self’) and the message is understood linguistically and cognitively (inner to your conscious mental experience or executive/self awareness but outer to your visual experience and absent from your body experience). The letters are more outer to your mind than the words, but not as outer as the optics available through your eyes. It’s all sensory experience and it is all inner, outer, and frame relative to different levels of participation. All sense is a frame making, breaking, and preserving experience which recontextualizes other frames as inner and outer.