Formal Cause

Class arrangement
Dynamic explanation
Essence principle

All individual things consist of matter and form. Matter is the principle of potentiality, or the ability to become multiple identifiable things. Form is the principle of determination and actuality, which accounts for the thing being the kind of thing it is. Accordingly, form is the functional organization that an individual shares with other members of its class.

“Cause, therefore, is after one manner said to be that, from which, being inherent, something is produced.” – Aristotle