Eric, Chris and Nick
I thought that Eric was just joking with his brick wall; in no way does a brick wall at the end of an alley have any meaning similar to ´an end in itself´ which means something entirely different, intrinsic self-justification, just as Nick has stated. Unless, of course, the play is on words which it might well be, and in that sense there would indeed be an end within the alley itself - one of brick.
Chris is perhaps confusing two things here: commissioned work as by the people he cited may or may not be art but its end is to fulfil the commission, not necessarily to be art; on the other side of the equation, the artist who takes the photograph, paints the picture or chips the stone to please himself may or may not be working to commision, but as an artist first his task is to create art.
There is an alternative way or, perhaps, there are exceptions to the rule, where photographers who undertake commercial work are also artists and even in spite of themselves, whatever they do is kissed by their magic and turns out to be a work of art, commissioned or not, which might be where some on Chris´ list fit best.
It quickly becomes obvious that we are no nearer to finding a happy consensus on what might be art!
Rob C