I need a phrase

Or, at most, a couple of sentences. It needs to sum up a range of subjects and ideas including stuff like:

• Literature


• Meaning


• Development of language (that is, development of the ability to use it and understand it, not the developement of languages)


• Linguistics


• How people communicate


• How stuff like the above changes, and why

There are some other ideas around these things, too, but they're not clear yet.

Any thoughts?