Exception not being caught

So, I've got a little piece of code designed to play with catching the exception that's thrown when an object doesn't have a __toString method. <?php class A { } $a = new A(); // Ayn would be proud, right? try { echo "a is ",$a,"\n"; } catch(Exception $e) { echo "\nException Caught: "; echo $e, $n; } ?> This does not run as expected. I'd think that when the implicit string conversion in the try block hits, the exception would be thrown, caught by the catch block, and relayed. Instead you don't ever see the words "exception caught" and you get "Catchable fatal error: Object of class A could not be converted to string." If it's catchable, why isn't it caught in my example? Thanks, Weston