Full Idea
It is necessary for the whole to be prior to the part. For if the whole body is put to death, there will no longer be a foot or a hand. For everything is defined by its function and by its capacity (so the hands and feet would no longer be the same).
Gist of Idea
The whole is prior to its parts, because parts are defined by their role
Source
Aristotle (Politics [c.332 BCE], 1253a20)
Book Reference
Aristotle: 'Politics', ed/tr. Reeve,C.D.C. [Hackett 2017], p.4
A Reaction
It may be a mistake to ask which of these is 'prior'. If bricks make a wall, the whole depends on the parts, but the parts can exist without the whole. They continue to be possible parts of a wall (unlike severed feet).
Related Ideas
Idea 5227 The nature of any given thing is determined by its end [Aristotle]
Idea 16598 Priority was a major topic of dispute for scholastics [Pasnau]