Stephen Bayley's obituary for Alan Fletcher in Sunday's Observer contained an interesting assertion:

'Graphic design' is what used to be called commercial art - at least by faux purists who felt that true 'art' was isolated from the brute necessities of vulgar trade and popular communication. As if Raphael had been cordoned off from Vatican gold or any need to communicate with believers or penitents. As if Damien Hirst maintained a fastidious distance from his discounted cash flow.

Hmm. Art and design clearly share many of the same skills in terms of mark-making. There, however, the similarities end.

In truth the fact that the financial transaction is up-front in design and hidden in fine art is something of a false dichotomy. Art remains a market-based activity, even if it is a rather rarefied one, just as all real production is rooted in economics. How art differs from design is that its propaganda serves the whims of only one master - the artist. Good design - or commercial art, if you like - serves a specific material purpose, be it economic, communicative or whatever else.

The demarcation wasn't always so clear. During the 19th century, the ideal of the artist changed from being a tradesperson to a kind of delinquent professional. This change was solidified by the rise of modernism in the twentieth century, but has its beginnings in eighteenth century romanticism, a movement which not only fetishised mythologising (especially self-mythologising) and individualism but was a rebellion against the growing importance of industrial production, or at least the grimy cities and money-grubbing "lower orders" who did the actual foul-smelling work.

Suddenly, the true artist was a man (and it was almost invariably men) who could see more clearly and who stood apart. No mere illustrator, these towering geniuses... Those popular artists who produced work specifically intended to support commercial activity, the proto-designers, why they were simply artisans.

Today we expect our artists to be philosophers, not "mere" decorators - which could explain why we so often end up with such poor decoration and one-quark thin imitations of philosophy.

Beyond a smattering of Baudrillard and Barthes, I recall no attempt on the part of most students to get to grips with the intricacies of critical thinking while I was attending art school. Not that that's a bad thing: students were instructed in art and professional practice and if they wanted to read Slavoj Zizek, as I did, then that was their own look-out.

Still, the snobbery which Bayley notes cuts both ways. Loathsome as the iconic image of the artist surely is, plenty of designers are only too willing to play the part assigned to them by the popular image of their jobs.