Metaphor changes language

This is one of the more lucid passages I discovered reading Owen Barfield:

Now apart from the actual invention of new words (an art in which many poets have excelled), the principal means by which this creation of meaning is achieved is – as has already been pointd out – metaphor. But it must be remembered that ANY specifically NEW use of a word or phrase is really a metaphor, since it attempts to arouse cognition of the unknown by suggestion from the known. I will take an example: the painter’s expression “point of view” was a metaphor the first time it was used with a psychological content. This content is today one of its accepted meanings – indeed, it is the most familiar one – but it could only have become so AFTER passing, explicity or implicityl, through the earlier stage of metaphor. In other words, either Coleridge or somebody else either said or thought (I am of course putting it a little crudely) ‘X is to the mind what “point of view” is to an observer of landscape’. And in so doing he enriched the content of the expression “point of view” just as Shakespeare enriched the content of ‘balm’ (and of ‘sleep’, too) when he called sleep the ‘balm of hurt minds’ (‘sleep is to hurt minds what balm is to hurt bodies’). Reflection will show that the ‘new’ use of an epithet – that is to say, its application to a substantive with which it has not hitherto been coupled – is also a concealed metaphor.

-Owen Barfield, Poetic Diction: The Making of Meaning, (Reader p.20)

Barfield goes on to explain in quite some detail how the word “ruin” evolved (via metaphor) to mean several different things over the course of history. This stuff is interesting, but Podictionary makes it more fun!