But can and will are birds of diff'rent feather.
Can is a swan, that bottles up its music,
And never lets it out till death is near;
But will's a piping bullfinch, that does ever
Whistle forth every note it has been taught,
To any fool that bids it. Now, sir, mark;—
Whoever's here, would fain be private here;
Whoever's here, depend on't, tell I can;—
Whoever's here, depend on't, tell I will not.