And one man in his life plays many parts.
Shakspeare: As You Like It.
Palladas, a Greek poet of the third century, has the following, translated by Merivale:—
This life a theatre we well may call,
Where every actor must perform with art,
Or laugh it through and make a farce of all,
Or learn to bear with grace his tragic part.
Pythagoras, who lived nearly two centuries later, also said,—
This world is like a stage whereon many play their parts.