The Black Box is simply the study of the relations between the
Experimenter and his environment, when special attention is given
To the flow of information. “A study of the real world thus
Becomes a study of transducers.” (Goldman, Information theory.)
Before we go further, the question of “emergent” properties
Should be clarified.
First let one fact be established. If a number of Black Boxes are
Given, and each is studied in isolation until its canonical represen-
Tation is established, and if they are coupled in a known pattern by
Known linkages, then it follows (S.4/8) that the behaviour of the
Whole is determinate, and can be predicted. Thus an assembly of
Black Boxes, in these conditions, will show no “emergent” prop-
Erties; i.e. no properties that could not have been predicted from
Knowledge of the parts and their couplings.
The concept of “emergence” has never been defined with pre-
Cision, but the following examples will probably suffice as a basis
For discussion:
Ammonia is a gas, and so is hydrogen chloride. When the
Two gases are mixed, the result is a solid— a property not pos-
Sessed by either reactant.
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Carbon, hydrogen and oxygen are all practically tasteless, yet
The particular compound “sugar” has a characteristic taste pos-
Sessed by none of them.
The twenty (or so) amino-acids in a bacterium have none of
Them the property of being “self-reproducing”, yet the whole, with
Some other substances, has this property.
If these examples are compared in detail with the processes of
Study and coupling of Black Boxes, it is soon seen that the exam-
Ples postulate much less knowledge of their parts than is postu-
Lated of the Black Boxes. Thus the prediction in regard to
Ammonia and hydrogen chloride is based on no more knowledge
Of each substance than that it is a gas. Similarly, of the twenty
Amino-acids all that is asked is “is it self- reproducing?” Were
Each amino-acid treated as a Black Box the examination would be
Far more searching. The input to a molecule is the set of electrical
And mechanical forces, in all distributions and combinations, that
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Can affect it; and its output is the set of all states, electrical and
Mechanical, that it can be in. Were this complete knowledge
Available, then the method of S.4/8 shows how the behaviour of
Many coupled amino-acids could be predicted; and among the
Predicted behaviours would be that of self-reproduction of the
Whole.
It will be seen that prediction of the whole’s behaviour can be
Based on complete or on incomplete knowledge of the parts. If the
Knowledge is complete, then the case is that of the Black Box
Whose canonical representation is known, the inputs or circum-
Stances being all those that may be given by the other Boxes to
Which it is to be coupled. When the knowledge of the parts is so
Complete, the prediction can also be complete, and no extra prop-
Erties can emerge.
Often, however, the knowledge is not, for whatever reason,
Complete. Then the prediction has to be undertaken on incomplete
Knowledge, and may prove mistaken. Sometimes all that is known
Of the parts is that every one has a certain characteristic. There
May be no better way of predicting than to use simple extrapola-
Tion — to predict that the whole will have it. Sometimes this
Proves justified; thus, if a whole is of three parts, each of pure cop-
Per, then we shall be correct if we predict that the whole is of pure
Copper. But often the method fails, and a new property can, if we
Please, be said to “emerge”.
It does in fact very commonly happen that when the system
Becomes large, so that the range of size from part to whole is very
Large, the properties of the whole are very different from those of
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A N I N T R O D UC T I O N T O C Y B E R NE T I C S
TH E BL AC K B O X
The parts. Biological systems are thus particularly likely to show
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The difference. We must therefore be on guard against expecting
The properties of the whole to reproduce the properties of the parts,
And vice versa.
The examples of ammonium chloride and sugar mentioned
Above are simple examples, but more complex cases occur. Con-
Sider, for instance, the concept of “localisation” of some function
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