Free Janus by Arthur Koestler

fundamental problems as the theory of evolution;
free will versus determinism; and the pathology and creativity of the
human mind.
     
     
     
12
     
     
As already mentioned, the purpose of this chapter is not to provide
a manual of hierarchies, but to convey some idea of the conceptual
framework on which this inquiry is based, and to give the reader the
'feel' of hierarchic thinking as opposed to the current reductionist
and mechanistic trends. To conclude this summary survey, I must mention,
however briefly, a few more principles which all hierarchic systems have
in common.
     
     
One obvious point is that hierarchies do not operate in a vacuum,
but interact with others. This elementary fact has given rise to much
confusion. If you look at a well-kept hedge surrounding a garden like
a living wall, the rich foliage of the entwined branches may make you
forget that the branches originate in separate bushes. The bushes are
vertical, arborizing structures. The entwined branches form horizontal networks at numerous levels. Without the individual plants there would
be no entwining, and no network. Without the network, each plant would be
isolated, and there would be no hedge and no integration of functions.
'Arborization' and 'reticulation' (net-formation) are complementary
principles in the architecture of organisms and societies. The circulatory
system controlled by the heart and the respiratory system controlled by
the lungs function as quasi-autonomous, self-regulating hierarchies,
but they interact on various levels. In the subject-catalogues in our
libraries the branches are entwined through cross-references. In cognitive
hierarchies -- universes of discourse -- arborization is reflected in the
'vertical' denotation (classification) of concepts, reticulation in their
'horizontal' connotations in associative nets.
     
     
The complementarity of arborization and reticulation yields relevant
clues to the complex problem of how memory works.*
     
* The section that follows is a summary of The Act of Creation,
     Book II, Ch. X, The Ghost in the Machine, Ch. V and VI,
     and of a paper read to the Harvard Medical School Symposium on
    'The Pathology of Memory'. [21]
     
     
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In Stevenson's novel Kidnapped , Alan Breck makes the casual remark:
'I have a grand memory for forgetting, David.' He speaks for all of us,
and not only those afflicted with aphasia or senility. Painful as it is,
we have to admit that a large proportion of our memories resembles the
dregs in a wine glass, the dehydrated sediments of experiences whose
flavour has gone -- or, to change the metaphor, they are like dusty
abstracts of past events on the shelves of a dimly lit archive.
Fortunately this applies only to one type or category of memories,
which I shall call abstractive memory. But there is another category,
derived from our capacity to recall past episodes, or scenes, or details
of scenes, with almost hallucinatory vividness. I shall call this the spotlight type of memory, and I shall contend that 'abstractive memory'
and 'spotlight memory' are different classes of phenomena, based on
different neural mechanisms.
     
     
Take abstractive memory first. The bulk of what we can remember of our
life history, and of the knowledge we have accumulated in the course of
it, is of the abstractive type.
     
     
The word 'abstract' has, in common usage, two main connotations: it is the
opposite of 'concrete', in the sense that it refers to a general concept
rather than a particular instance; in the second place, an 'abstract' is a
condensation of the essence of a longer document. Memory is abstractive in
both senses. I watch a television play. The exact words of each actor are
forgotten within a few seconds; only their abstracted meaning is retained.
The next morning I can only remember the sequence of scenes which constituted
the story. A month later, all I can remember is that the play was about a
gangster on the run. Much the same happens to the