Abstract
This is the first of a series of mini-essays by Dr J. C. Jones that will be published in the next few issues. These have been peer reviewed to a degree appropriate to ‘notes’ rather than full articles. It is hoped that they will engender discussion, and readers with responses to any particular mini-essay are encouraged to contact Dr Jones himself or the journal editor. It is also believed that they will provide teaching material, in which case acknowledgement is requested. Editor