
Originally Posted by
Jonathan
It's because one is implied by the other. An internal structure exists in a space. An external structure defines a space within it. A space has a structure. Actions within a space have internal relationships that define an internal structure.
For it not to be so would be like drawing an asterisk without any space between the lines that come out, or like drawing a square with no space in side it, or like drawing something that doesn't have an outside to it, or like to draw something where no relationships can exist between the elements at all, ever.
So basically, one implies the other. It's just simple geometry.