Margaret L. Blaise (née Jones, 1878-1935) was one of the most accomplished and fervent pioneers of the Esperanto movement in Britain. The British Library holds a few editions of her innovative The Esperanto Manual (1908 and further editions in 1911 and 1913) and this reprint of the article ‘A World Language: Why not Esperanto?’, first published in The Link in June 1916. In this booklet Blaise puts the case for Esperanto as an ‘easy, fascinating and successful auxiliary language’, which in addition has another remarkable quality: ‘Moreover, there is really behind the language itself, a sort of fraternal feeling, nearly always existing, which renders a service from one foreigner to another a thing of duty and pleasure, as well as of business’. She gives numerous examples of the usefulness of Esperanto on ‘numberless occasions’ at the beginning of the war and afterwards, in hospitals and internment camps: ‘everywhere where native languages are of no avail, there are instances where Esperanto has proved itself a boon and a blessing incalculable’. Blaise looks forward to the future peace negotiations and the ‘new fields of commerce’ that will open up after the war. ‘Everything to-day proves, therefore, not only that there is an urgent demand for a lingua franca, but that Esperanto is that universal auxiliary language…’ she concludes.