Metaphor is much more than a poetic device. It's a way of thinking. It encourages the mind to see a thing through another. It can be applied to every facet of human endeavour. It is one of the main reasons that reading Shakespeare can be of so much value to everyone, not only English majors, teachers and writers. In fact, it sometimes seems as if every aspect of his work is shot through with the idea. Today, let's consider once more (I wrote about this in a different context in my post of October 8, 2010) what is often called "word class conversion", the technique whereby one part of speech is used as another. Here's an example from act two, scene three of King Lear - the speech in which Edgar decides that the only way to avoid being caught by his father's forces (he's been framed by his half-brother, Edmund) is to disguise himself as a "Bedlam beggar". Check out the three successive nouns used as verbs in the ninth and tenth lines:

I heard myself proclaim'd,

And by the happy hollow of a tree

Escap'd the hunt. No port is free, no place

That guard and most unusual vigilance

Does not attend my taking. Whiles I may scape,

I will preserve myself; and am bethought

To take the basest and most poorest shape

That ever penury, in contempt of man,

Brought near to beast. My face I'll grime with filth,

Blanket my loins, elf all my hair in knots,

And with presented nakedness outface

The winds and persecutions of the sky.

The country gives me proof and precedent

Of Bedlam beggars, who, with roaring voices,

Strike in their numb'd and mortified bare arms

Pins, wooden pricks, nails, sprigs of rosemary;

And with this horrible object, from low farms,

Poor pelting villages, sheepcotes, and mills,

Sometime with lunatic bans, sometime with prayers,

Enforce their charity. 'Poor Turlygod! poor Tom!'

That's something yet! Edgar I nothing am.