On today's Smalltalk Daily, we take a look at Pragmas. There's been a discussion about those recently on our mailing lists, and Michael posted on it today - I like this summation:

So why do we blend the source code to a method with the signature of a method? Well, pragmatism. It's incredibly convenient to be able to edit the signature with the code itself. When you stop to think about it - pragmas are the same. Is it easier to pull down a menu to define an attribute on a method, or easy enough just to write some code that you can copy, paste, move around, edit - all in the same place that's contextually bound to the method you're actually working on...

For a different point of view, try Antony's post: