Language Power

My article "Speed Programming?" talked indirectly about the power of languages. This isn't the first time this subject has come up. For instance, last month I was discussing this very subject with a friend of mine.

In the core of this particular debate was this old article http://www.paulgraham.com/avg.html by Paul Graham where he suggested that "programming languages vary in power." and "that if you have a choice of several languages, it is, all other things being equal, a mistake to program in anything but the most powerful one". As a note he is a Lisp expert and suggests that Lisp is one of the more powerful languages available.

However, ignoring the fact that he chooses Lisp, is this argument valid? I've been thinking about this for a good while now and as my previous article might suggest I'm still looking for an answer.

The only thing that I would say (with a possible difference of opinion to his argument) is that I have found the libraries available also seriously factor into the amount of work you can do in a fixed amount of time - strong examples are Objective-C with Cocoa and Python with the Python libraries.

I actually think the difference between a language and it's libraries is more blurred than clear cut. Consider C and its strings / string manipulation libraries - although you can do them "by hand" really they could be part of the language specification. Another more black and white case is that Objective-C/Cocoa provides advanced data types like dictionaries, vector-style arrays, sets and strings entirely by the use of classes and method calls. These feel like part of the strengths of the language when you are programming although they are really part of the library (framework).

Conversely, I guess, quite often libraries can be used with different languages by the use of shared library bridges. For example SDL is available for many languages even though it's written in C. Perhaps languages and libraries not totally unlinked, but can certainly aid each other?