The Law of Unity in Description.

The word unity, as applied to a description, means one¬ness of effect. It is secured by excluding from a picture details that strike us as out of harmony with the general impression that the object we are de¬scribing makes upon us. In this extract from Charlemagne.
A description which produces upon the hearer singleness of impression has unity. The word which characterizes this impression expresses the funda¬mental quality of the description.