In his writings Jespersen has expressed his conviction that an auxiliary language should be one which is based on the material of the European languages but which should be regularly constructed and should be independent of national usages, with a complete grammar of its own. It should have its roots in the European languages and yet be autonomous in its own structure. The constructed auxiliary language should be neutral and should serve as a second language beside our mother tongue.
Jespersen gives numerous examples to show that though a second ethnic language may be taught at school and college, the result is not, of necessity, a command of that language by the student, but rather a first introduction. If the student has, after such initial study, the opportunity to visit and to live in the country whose language he studied, then only can he hope to master the language eventually. The mere study of a foreign language does not, in most cases, achieve results which justify the expense of energy and time which it demands.
Under the heading `Ignorance of foreign languages' Jespersen speaks of the inability of prominent statesmen of the years 1914-1918 to use efficiently a language which they must have tried to acquire during many years of arduous study at school and at college. "Sir Edward Grey could not speak French, and the French ambassador, Cambon, spoke bad English. None of the French or English generals, with the exception of Lord Kitchener, spoke the other nation's language at all well, and at the Peace Conference Clemenceau gained an undue ascendancy because he was practically the only one who had complete command of both languages." (An International Language, p. 16). H. Diels formulated, in a few words, one of the chief reasons for a scientific, constructed language; Jespersen quotes this scholar and adds a confession which few would have expected from a linguist of Jespersen's repute: "`Incalculable are the intellectual losses incurred every year in consequence of the national hobby of small, but highly gifted and scientifically active peoples, who insist that scientific works (which cannot all of them be translated) should appear in their own, narrowly circumscribed languages.' For my part," Jespersen adds, "though I have spent most of my life studying different languages, I have sometimes been obliged to lay aside as unread books and papers which I should have liked very much to study, but which happened to be written in a tongue with which I was not sufficiently familiar."
This situation confronts many scientists who are obliged by their occupation to follow developments in other countries, yet who cannot devote sufficient time to become conversant with more than one or two languages which they find are essential. Developments and discoveries outside the linguistic boundaries of a small nation, or of a nation whose language it is difficult to learn, are often ignored in other countries. Even today it is impossible to obtain all the writings of Freud or Einstein in English, or to obtain the transactions of foreign learned societies, reports of specialised research issued periodically by scientific institutions in many countries. Crowther reports in his book Soviet Science that about four thousand scientists are engaged in research work of institutions attached to the Sovietrussian Academy of Sciences, and the papers published by them must be considerable.
The American journal Science (August, 1935) published a `Plea to scientists of the Soviet Union' in which the author mentioned the intellectual losses incurred by the fact that Russian scientists tend to publish the results of their researches in Russian, a tendency fostered by a new national pride. J. Lansbury adds an interesting comment: "There are in the world about 24,000 scientific journals. In one medical library in New York alone we find 1,831 periodicals. 55 per cent. of these are written in English; of the remaining 45 per cent., about one third is in German, one fifth in French, and about a tenth in either Italian or Spanish. The other journals are written in any one of the languages of Europe or Asia and are, for most Americans, wholly incomprehensible."
Jespersen has asserted that it is incomparably easier to learn a constructed language and to use it as a common means of communication beside the mother tongue than to try to acquire a working knowledge of an ethnic language. Experiments carried out in America have proved the correctness of this assertion.
Prof. Thorndike has, over a period of six years, conducted experimental classes to determine the relative ease of learning a constructed language as compared with learning an ethnic language, and further to discover the influence of the study of a constructed language on subsequent language learning. He found that, given the same time to study a constructed and and an ethnic language, the results achieved in the auxiliary language are from five to fifteen times those of an ethnic language, according to the difficulty of the latter (Language Learning, 1933, Columbia University).