Sorry, many dynamic languages prevent against this. For example:
$ perl -Mstrict -E 'say $foo'
Global symbol "$foo" requires explicit package name at -e line 1.
Also, his comment about properties on objects is very debatable, too. Ignoring that the term "property" is overloaded and not defined, since I use roles (see: http://www.slideshare.net/Ovid/inheritance-versus-roles-1799...), I find out at compile time if my classes are missing an attribute or method (actually it's composition time, but that's splitting a hair that most will never notice). In short, I don't get frantic 2AM phone calls about a batch process trying to call a non-existent method.