But the way people commonly use the word nowadays it means something all of whose parts are mutually interdependent - not only for their mutual action, but for their meaning and for their existence.

A corporation is organized as a system - it has this department, that department, that department... they don't have any meaning separately; they only can function together. And also the body is a system. Society is a system in some sense. And so on.

People are no longer primarily in opposition, nor can they be said to be interacting, rather they are participating in this pool of common meaning which is capable of constant development and change.

Appearance is something absolute, but reality is not that way - everything is interdependent, not absolute.

if we knew the meaning of life it would cease to have meaning

Language has no independent existence apart from the people who use it. It is not an end in itself; it is a means to an end of understanding who you are and what society is like.