The Complaint: or Night Thoughts (excerpt)

By Nature's law, what may be, may be now;
  There's no prerogative in human hours.
  In human hearts what bolder thought can rise,
  Than man's presumption on to-morrow's dawn?
  Where is to-morrow? In another world.
  For numbers this is certain; the reverse
  Is sure to none; and yet on this perhaps,
  This peradventure, infamous for lies,
  As on a rock of adamant we build
  Our mountain hopes, spin out eternal schemes
  As we the Fatal Sisters could out-spin,
  And big with life's futurities, expire.
  Not ev'n Philander had bespoke his shroud,
  Nor had he cause; a warning was deny'd:
  How many fall as sudden, not as safe!
  As sudden, though for years admonish'd home.
  Of human ills the last extreme beware;
  Beware, Lorenzo, a slow-sudden death.
  How dreadful that deliberate surprise!
  Be wise to-day; 'tis madness to defer;
  Next day the fatal precedent will plead;
  Thus on, till wisdom is push'd out of life.
  Procrastination is the thief of time;
  Year after year it steals, till all are fled,
  And to the mercies of a moment leaves
  The vast concerns of an eternal scene.
  If not so frequent, would not this be strange?
  That 'tis so frequent, this is stranger still.
  Of man's miraculous mistakes this bears
  The palm, "That all men are about to live,"
  For ever on the brink of being born,
  All pay themselves the compliment to think
  They, one day, shall not drivel: and their pride
  On this reversion takes up ready praise;
  At least, their own; their future selves applauds;
  How excellent that life they ne'er will lead!
  Time lodg'd in their own hands is Folly's vails;
  That lodg'd in Fate's to Wisdom they consign.
  The thing they can't but purpose, they postpone.
  'Tis not in folly not to scorn a fool,
  And scarce in human wisdom to do more.
  All promise is poor dilatory man,
  And that through every stage; when young, indeed,
  In full content we sometimes nobly rest,
  Unanxious for ourselves; and only wish,
  As duteous sons our fathers were more wise.
  At thirty man suspects himself a fool,
  Knows it at forty, and reforms his plan;
  At fifty chides his infamous delay,
  Pushes his prudent purpose to resolve;
  In all the magnanimity of thought
  Resolves, and re-resolves, then dies the same.