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.