The structural unity of the parts is such that, if any one of them is displaced or removed, the whole will be disjointed and disยญturbed. For a thing whose presence or absence makes no visible difference is not an organic part of the whole.
AristotleNature does nothing without a purpose. In children may be observed the traces and seeds of what will one day be settled psychological habits, though psychologically a child hardly differs for the time being from an animal.
Aristotle