SONNET 129 SHAKESPEARE:

Th' expense of spirit in a waste of shame
Is lust in action; and till action, lust
Is perjured, murd'rous, bloody, full of blame,
Savage, extreme, rude, cruel, not to trust,

Enjoyed no sooner but despised straight,
Past reason hunted, and no sooner had
Past reason hated as a swallowed bait
On purpose laid to make the taker mad;

Mad in pursuit and in possession so,
Had, having, and in quest to have, extreme;
A bliss in proof and proved, a very woe;
Before, a joy proposed; behind, a dream.

All this the world well knows, yet none knows well
To shun the heaven that leads men to this hell.

It is an impersonal poem, in which the poet doesn't appear, and it is a metaphor for sexual experience.

The first quarain begings with a negative climax in which the waste of energy is seem as a shamefull waste referring eighter to energy or to sperm. Luxury acts as if it could act by itself and it is full of blame. Using a chiasmus "lust in action- action lust", Shakerpeare emphatizes the negative aspects of lust which is savage extreme rude, cruel, but also (more obvioussly) not to trust.

The second quatrain evidences, in the first lines the quick changes of attitude: enjoyed vs despised. The transformation is vey fast. Even in the following lines the attitude changes instantly between, before and after: past reason is hunted and quickly hated.

In the third quatran man becomes man and out of control in action. That's to say following physical attraction man doesn't use the Brain and he is often unable to control himself. He wants to have more and more and extremely more!

It is the experience of a deep joy followed by great sorrow. the big joy Lust proposes becomes at the end a dream.

In the last couplet Shakespeare ends the poem supporting that what he said is well known by the world, but none knows it well. Even if man experienced it, he never learns because he is attracted by Lust which through heaven brings him to hell.