I want to do something like:
\epigraph{Elbert Hubbard}{
Many people fail in life, not for lack of ability or brains or even
courage,

but simply because they have never organized their energies around a
goal.}

Because I want to have the but on the second line, with the rest of the text. But this gives:
Runaway argument?
{ Many people fail in life, not for lack of ability or brains or even\ETC.
! Paragraph ended before \epigraph was complete.
<to be read again>
                   \par

I managed to get what I want with:
\epigraph{Elbert Hubbard}{
  Many people fail in life, not for lack of ability or brains or even
  courage,
  \blank[disable]
  but simply because they have never organized their energies around a
  goal.
}

But I was wondering if there is a better solution?