Unexplainable? Jackson Pollock’s painting, Number 17, 1949 … ‘The pictures I contemplate painting would constitute a halfway state’, he said. Photograph: Reuters

It is a vice of second-rate art to come with its own eloquent explanation attached. If an artist can translate the meaning and purpose of a work into easily understandable words, it means one of two things. Either the artist is lying, in order to ease the way with patrons and funders; or the artist is a fool. And if dishonesty is the reason, that too is something that vitiates art. No serious art is easy to interpret. Nor is there ever a single valid interpretation of art. If art is good, there are many things to be said about it and much that will remain unsayable.

Yet, there are more and more pressures today on artists to explain themselves. Once, an artist was allowed to hide behind a vague and mysterious aura. The American abstract expressionist painters made grand pronouncements about their work that are so enigmatic they give away no hostages – nor do the kinds of epigrammatic comments made by Francis Bacon. Yet artists in Britain today are always offering explanations for what they do.

If you’re looking for the root cause of anything annoying, silly or spurious in the culture of art in 21stcentury Britain the source of the problem is never hard to locate. Once again the culprit is … public art, in which the popularization of art, the determination of institutions from parks to to local councils to be associated with it, and a lingering British Puritan visual clumsiness produce a lot of guff as artists try to promote the accessible virtues of their ideas.