According to William Shakespeare in As You Like It:
- All the world's a stage,
- And all the men and women merely players,
- They have their exits and entrances,
- And one man in his time plays many parts,
- His acts being seven ages.
These are, approximately:
- infancy,
- childhood,
- the lover,
- the soldier,
- the adult, with "fair round belly, with good capon lin'd, / With eyes severe, and beard of formal cut",
- old age, with "his big manly voice, / Turning again towards childish treble, pipes / And whistles in his sound.",
- senility and death.