What Principle of Design is used to create cohesiveness in a work of art?

Often in bluegrass the mandolin chords are so staccato they sound like drum beats arpeggios bass lines melodies

In the centauromachy metope of the parthenon, human is to centaur as is to .

Which does the author mean by " nature had to kindle all the fires, for man by his own effort was unable to produce a spark