BTW chromatic gave some background on the philosophy behind his Modern Perl book in
this thread:
Modern Perl assumes you're already decent at programming, so it elides some basic stuff in favor of explaining how
Perl works from philosophy to programming in the large. Learning Perl assumes you've never programmed before,
so it spends more time on the basics, covers less of the language, and doesn't explore the philosophy of Perl in as much detail.