First off, what are maps? To me a map is an analogy; from an old dictionary definition of the word 'an agreement, likeness, or proportion between the relations of things to one another...'.
Maps have shapes, points, lines and polygons, which have to be honest. Part of the art (if art it is) comes from how styles are applied to the shapes and by how the text, labelling and furniture is selected and placed. The shapes of course can not be altered in the interests of appearance and this imposes necessary constraints on the map maker, who's job it is to use his skills to make the map tell a story in the simplest way possible. I think it is inevitable that a map which tells its story well will also be attractive to the eye, but this, in my opinion, would not make it art. Maps are things of purpose and good ones can be interesting and appealing, but not art I think.
Now I'm in trouble.
I like what you said Nick. There can be 'art' in the design, but if art is a pure expression and maps are function first, then a map can not be a pure expression and be functional (opposing forces).
Could not disagree more. Art is what and where we find it and although the term may have a definition art itself is a fairly personal concept defined by the individual. A person may find art, whether man made or not, in almost anything. To me an artful map can indeed be a functional one, these are not mutually exclusive concepts in design.
The art in "art & science" of cartography is a different subject altogether and reflects the subjective nature of creating a graphic representation of the world as well as the creative process of map mapping overall.
To the idea that a map must be 'honest', again I respectfully disagree. A map as a representation of some part of the world is by it's very nature 'dishonest'. It carries with it in style and design all of it's makers perceptions and biases about the subject being mapped (we do this whether conscious of it or not). And just like a photograph, simply by taking a segment of the world and showing it in frame we alter its context and reality. But beyond that esoterica is the fact that many maps (even good maps) are purposefully made to be misleading or dishonest (see "how to lie with maps", Monmonier).
A map has to have a function, otherwise it is 'artful representation of a map form', so there are inherent barriers to full art expression. Certainly, a map can have be artfully created, just as a photojournalist who takes photos with a purpose can be artful.