"(Harold Innis) changed his procedure from working with a "point of view"
 to that of the generating of insights by the method of "interface",
 as it is named in chemistry. "Interface" refers to the interaction of
 substances in a kind of mutual irritation. In art and poetry this is
 precisely the technique of "symbolism" (Greek 'symballein' -- to throw
 together) with its paratactic procedure of juxtaposing without connectives.
 It is the natural form of conversation or dialogue rather than of written
 discourse. In writing, the tendency is to isolate an aspect of some matter
 and to direct steady attention upon that aspect. In dialogue there is an
 equally natural interplay of multiple aspects of any matter. This interplay
 of aspects can generate insights or discovery. By contrast, a point of view
 is merely a way of looking at something. But an insight is the sudden
 awareness of a complex process of interaction. An insight is a contact with
 the life of forms."
- From Media and Cultural Change, Marshall McLuhan's introduction to the
  1964 edition of The Bias of Communication by Harold Innis