The first clause is switched back to front: the first line tells what lust that acts is.


 The act that spends self in a waste of shame
 Is lust that acts; and till it acts, that lust
 Lies, kills, is stained with blood, is full of blame,
 Harsh, too far, rude, cruel, not to trust;
 As soon lived up then hate it straight;
 Past all sense we hunt it; and, soon as had,
 Past all sense we hate it, as mouth-bit bait,
 That's laid as if to make who takes it mad:
 Mad in the chase, and when you have it too;
 Had, now have, and in quest to have, too steep;
 A bliss in proof, and proved, in truth, a woe;
 To come, a joy that's planned; once done, a dream.
   All this the world well knows; yet none knows well
   To shun the bliss that leads men to this hell.

                                -- Will the Bard