I've come across the idea of Aspect Oriented Programming, and I have some concerns with it.

The basic idea seems to be that we want to take cross-cutting concerns which aren't well modularized using object and modularize them. That is all very fine and well.

But the implementation of AOP seems to be that of modifying code from outside of the module. So, for example, an aspect could be written that changes what happens when a particular object is passed as a parameter in a function. This seems to go directly against the idea of modules. I should not be able to modify a module's behavior from outside of that module, otherwise the whole point of modules are overturned. But aspects seem to be doing exactly that!

Basically, aspects seems to be a form of code patching. It may useful for some quick hacks; but, as a general principle perhaps its not something you want to do. Aspect Oriented Programming seems to me taking a bad practice and raising to a general design principle.

Is AOP a good practice? Are certain programming problems solved more elegantly with AOP?