Lines

Line: Paul Klee defined a line as a "point set in motion"

http://nowiknow.com/making-it-rain/
Rain is a lot of points(water droplets) set in motion by gravity

Implied Line: a line created by the eye while following a set of points, objects, figures, shapes, etc.

The landing lights create an implied line.

Psychic Line: It is a non-existent line, created sub-consciously.

A psychic line is created when we look to the left to know what the dragons are staring at.