>perl -wMstrict -le
"my $letter =
   qq{One Mr. John Doe was a very good friend of John Jacob \n}  .
   qq{Astor. They met often with William and Henry James and \n} .
   qq{Capt. Jean-Luc Picard at the quaint Tavern On The Green.};
 print qq{''$letter''};
 my $Capped    = qr{ [[:upper:]] [[:lower:]]+ }xms;
 my $name      = qr{ $Capped (?: - $Capped)*  }xms;
 my $full_name = qr{ $name   (?: \s+ $name)+  }xms;
 my @names =
   map { tr{ \t\n}{ }s;  $_ }
   $letter =~ m{ $full_name }xmsg
   ;
 print qq{'$_'} for @names;
"
''One Mr. John Doe was a very good friend of John Jacob
Astor. They met often with William and Henry James and
Capt. Jean-Luc Picard at the quaint Tavern On The Green.''
'One Mr'
'John Doe'
'John Jacob Astor'
'Henry James'
'Jean-Luc Picard'
'Tavern On The Green'